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* malloc/malloc.c (rEALLOc): Only free memory for size 0 if oldmem is != NULL. 1999-04-28 Andreas Jaeger <aj@arthur.rhein-neckar.de> * malloc/malloc.c (REALLOC_ZERO_BYTES_FREES): Define it to follow ISO C9x and Unix98. 1999-04-28 Ulrich Drepper <drepper@cygnus.com>
4707 lines
143 KiB
C
4707 lines
143 KiB
C
/* Malloc implementation for multiple threads without lock contention.
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Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
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and Doug Lea <dl@cs.oswego.edu>, 1996.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* V2.6.4-pt3 Thu Feb 20 1997
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This work is mainly derived from malloc-2.6.4 by Doug Lea
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<dl@cs.oswego.edu>, which is available from:
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ftp://g.oswego.edu/pub/misc/malloc.c
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Most of the original comments are reproduced in the code below.
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* Why use this malloc?
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This is not the fastest, most space-conserving, most portable, or
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most tunable malloc ever written. However it is among the fastest
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while also being among the most space-conserving, portable and tunable.
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Consistent balance across these factors results in a good general-purpose
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allocator. For a high-level description, see
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http://g.oswego.edu/dl/html/malloc.html
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On many systems, the standard malloc implementation is by itself not
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thread-safe, and therefore wrapped with a single global lock around
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all malloc-related functions. In some applications, especially with
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multiple available processors, this can lead to contention problems
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and bad performance. This malloc version was designed with the goal
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to avoid waiting for locks as much as possible. Statistics indicate
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that this goal is achieved in many cases.
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* Synopsis of public routines
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(Much fuller descriptions are contained in the program documentation below.)
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ptmalloc_init();
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Initialize global configuration. When compiled for multiple threads,
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this function must be called once before any other function in the
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package. It is not required otherwise. It is called automatically
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in the Linux/GNU C libray or when compiling with MALLOC_HOOKS.
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malloc(size_t n);
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Return a pointer to a newly allocated chunk of at least n bytes, or null
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if no space is available.
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free(Void_t* p);
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Release the chunk of memory pointed to by p, or no effect if p is null.
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realloc(Void_t* p, size_t n);
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Return a pointer to a chunk of size n that contains the same data
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as does chunk p up to the minimum of (n, p's size) bytes, or null
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if no space is available. The returned pointer may or may not be
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the same as p. If p is null, equivalent to malloc. Unless the
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#define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
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size argument of zero (re)allocates a minimum-sized chunk.
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memalign(size_t alignment, size_t n);
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Return a pointer to a newly allocated chunk of n bytes, aligned
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in accord with the alignment argument, which must be a power of
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two.
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valloc(size_t n);
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Equivalent to memalign(pagesize, n), where pagesize is the page
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size of the system (or as near to this as can be figured out from
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all the includes/defines below.)
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pvalloc(size_t n);
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Equivalent to valloc(minimum-page-that-holds(n)), that is,
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round up n to nearest pagesize.
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calloc(size_t unit, size_t quantity);
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Returns a pointer to quantity * unit bytes, with all locations
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set to zero.
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cfree(Void_t* p);
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Equivalent to free(p).
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malloc_trim(size_t pad);
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Release all but pad bytes of freed top-most memory back
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to the system. Return 1 if successful, else 0.
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malloc_usable_size(Void_t* p);
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Report the number usable allocated bytes associated with allocated
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chunk p. This may or may not report more bytes than were requested,
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due to alignment and minimum size constraints.
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malloc_stats();
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Prints brief summary statistics on stderr.
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mallinfo()
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Returns (by copy) a struct containing various summary statistics.
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mallopt(int parameter_number, int parameter_value)
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Changes one of the tunable parameters described below. Returns
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1 if successful in changing the parameter, else 0.
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* Vital statistics:
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Alignment: 8-byte
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8 byte alignment is currently hardwired into the design. This
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seems to suffice for all current machines and C compilers.
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Assumed pointer representation: 4 or 8 bytes
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Code for 8-byte pointers is untested by me but has worked
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reliably by Wolfram Gloger, who contributed most of the
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changes supporting this.
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Assumed size_t representation: 4 or 8 bytes
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Note that size_t is allowed to be 4 bytes even if pointers are 8.
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Minimum overhead per allocated chunk: 4 or 8 bytes
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Each malloced chunk has a hidden overhead of 4 bytes holding size
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and status information.
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Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead)
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8-byte ptrs: 24/32 bytes (including, 4/8 overhead)
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When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
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ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
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needed; 4 (8) for a trailing size field
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and 8 (16) bytes for free list pointers. Thus, the minimum
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allocatable size is 16/24/32 bytes.
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Even a request for zero bytes (i.e., malloc(0)) returns a
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pointer to something of the minimum allocatable size.
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Maximum allocated size: 4-byte size_t: 2^31 - 8 bytes
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8-byte size_t: 2^63 - 16 bytes
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It is assumed that (possibly signed) size_t bit values suffice to
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represent chunk sizes. `Possibly signed' is due to the fact
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that `size_t' may be defined on a system as either a signed or
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an unsigned type. To be conservative, values that would appear
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as negative numbers are avoided.
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Requests for sizes with a negative sign bit will return a
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minimum-sized chunk.
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Maximum overhead wastage per allocated chunk: normally 15 bytes
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Alignment demands, plus the minimum allocatable size restriction
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make the normal worst-case wastage 15 bytes (i.e., up to 15
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more bytes will be allocated than were requested in malloc), with
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two exceptions:
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1. Because requests for zero bytes allocate non-zero space,
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the worst case wastage for a request of zero bytes is 24 bytes.
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2. For requests >= mmap_threshold that are serviced via
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mmap(), the worst case wastage is 8 bytes plus the remainder
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from a system page (the minimal mmap unit); typically 4096 bytes.
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* Limitations
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Here are some features that are NOT currently supported
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* No automated mechanism for fully checking that all accesses
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to malloced memory stay within their bounds.
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* No support for compaction.
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* Synopsis of compile-time options:
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People have reported using previous versions of this malloc on all
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versions of Unix, sometimes by tweaking some of the defines
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below. It has been tested most extensively on Solaris and
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Linux. People have also reported adapting this malloc for use in
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stand-alone embedded systems.
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The implementation is in straight, hand-tuned ANSI C. Among other
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consequences, it uses a lot of macros. Because of this, to be at
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all usable, this code should be compiled using an optimizing compiler
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(for example gcc -O2) that can simplify expressions and control
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paths.
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__STD_C (default: derived from C compiler defines)
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Nonzero if using ANSI-standard C compiler, a C++ compiler, or
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a C compiler sufficiently close to ANSI to get away with it.
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MALLOC_DEBUG (default: NOT defined)
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Define to enable debugging. Adds fairly extensive assertion-based
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checking to help track down memory errors, but noticeably slows down
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execution.
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MALLOC_HOOKS (default: NOT defined)
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Define to enable support run-time replacement of the allocation
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functions through user-defined `hooks'.
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REALLOC_ZERO_BYTES_FREES (default: NOT defined)
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Define this if you think that realloc(p, 0) should be equivalent
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to free(p). Otherwise, since malloc returns a unique pointer for
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malloc(0), so does realloc(p, 0).
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HAVE_MEMCPY (default: defined)
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Define if you are not otherwise using ANSI STD C, but still
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have memcpy and memset in your C library and want to use them.
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Otherwise, simple internal versions are supplied.
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USE_MEMCPY (default: 1 if HAVE_MEMCPY is defined, 0 otherwise)
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Define as 1 if you want the C library versions of memset and
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memcpy called in realloc and calloc (otherwise macro versions are used).
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At least on some platforms, the simple macro versions usually
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outperform libc versions.
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HAVE_MMAP (default: defined as 1)
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Define to non-zero to optionally make malloc() use mmap() to
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allocate very large blocks.
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HAVE_MREMAP (default: defined as 0 unless Linux libc set)
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Define to non-zero to optionally make realloc() use mremap() to
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reallocate very large blocks.
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malloc_getpagesize (default: derived from system #includes)
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Either a constant or routine call returning the system page size.
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HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined)
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Optionally define if you are on a system with a /usr/include/malloc.h
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that declares struct mallinfo. It is not at all necessary to
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define this even if you do, but will ensure consistency.
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INTERNAL_SIZE_T (default: size_t)
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Define to a 32-bit type (probably `unsigned int') if you are on a
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64-bit machine, yet do not want or need to allow malloc requests of
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greater than 2^31 to be handled. This saves space, especially for
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very small chunks.
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_LIBC (default: NOT defined)
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Defined only when compiled as part of the Linux libc/glibc.
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Also note that there is some odd internal name-mangling via defines
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(for example, internally, `malloc' is named `mALLOc') needed
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when compiling in this case. These look funny but don't otherwise
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affect anything.
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LACKS_UNISTD_H (default: undefined)
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Define this if your system does not have a <unistd.h>.
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MORECORE (default: sbrk)
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The name of the routine to call to obtain more memory from the system.
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MORECORE_FAILURE (default: -1)
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The value returned upon failure of MORECORE.
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MORECORE_CLEARS (default 1)
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True (1) if the routine mapped to MORECORE zeroes out memory (which
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holds for sbrk).
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DEFAULT_TRIM_THRESHOLD
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DEFAULT_TOP_PAD
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DEFAULT_MMAP_THRESHOLD
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DEFAULT_MMAP_MAX
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Default values of tunable parameters (described in detail below)
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controlling interaction with host system routines (sbrk, mmap, etc).
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These values may also be changed dynamically via mallopt(). The
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preset defaults are those that give best performance for typical
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programs/systems.
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DEFAULT_CHECK_ACTION
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When the standard debugging hooks are in place, and a pointer is
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detected as corrupt, do nothing (0), print an error message (1),
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or call abort() (2).
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*/
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/*
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* Compile-time options for multiple threads:
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USE_PTHREADS, USE_THR, USE_SPROC
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Define one of these as 1 to select the thread interface:
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POSIX threads, Solaris threads or SGI sproc's, respectively.
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If none of these is defined as non-zero, you get a `normal'
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malloc implementation which is not thread-safe. Support for
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multiple threads requires HAVE_MMAP=1. As an exception, when
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compiling for GNU libc, i.e. when _LIBC is defined, then none of
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the USE_... symbols have to be defined.
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HEAP_MIN_SIZE
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HEAP_MAX_SIZE
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When thread support is enabled, additional `heap's are created
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with mmap calls. These are limited in size; HEAP_MIN_SIZE should
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be a multiple of the page size, while HEAP_MAX_SIZE must be a power
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of two for alignment reasons. HEAP_MAX_SIZE should be at least
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twice as large as the mmap threshold.
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THREAD_STATS
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When this is defined as non-zero, some statistics on mutex locking
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are computed.
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*/
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/* Preliminaries */
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#ifndef __STD_C
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#if defined (__STDC__)
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#define __STD_C 1
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#else
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#if __cplusplus
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#define __STD_C 1
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#else
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#define __STD_C 0
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#endif /*__cplusplus*/
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#endif /*__STDC__*/
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#endif /*__STD_C*/
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#ifndef Void_t
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#if __STD_C
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#define Void_t void
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#else
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#define Void_t char
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#endif
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#endif /*Void_t*/
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#if __STD_C
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# include <stddef.h> /* for size_t */
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# if defined _LIBC || defined MALLOC_HOOKS
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# include <stdlib.h> /* for getenv(), abort() */
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# endif
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#else
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# include <sys/types.h>
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#endif
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/* Macros for handling mutexes and thread-specific data. This is
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included early, because some thread-related header files (such as
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pthread.h) should be included before any others. */
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#include "thread-m.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <stdio.h> /* needed for malloc_stats */
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/*
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Compile-time options
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*/
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/*
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Debugging:
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Because freed chunks may be overwritten with link fields, this
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malloc will often die when freed memory is overwritten by user
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programs. This can be very effective (albeit in an annoying way)
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in helping track down dangling pointers.
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If you compile with -DMALLOC_DEBUG, a number of assertion checks are
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enabled that will catch more memory errors. You probably won't be
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able to make much sense of the actual assertion errors, but they
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should help you locate incorrectly overwritten memory. The
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checking is fairly extensive, and will slow down execution
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noticeably. Calling malloc_stats or mallinfo with MALLOC_DEBUG set will
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attempt to check every non-mmapped allocated and free chunk in the
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course of computing the summaries. (By nature, mmapped regions
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cannot be checked very much automatically.)
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Setting MALLOC_DEBUG may also be helpful if you are trying to modify
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this code. The assertions in the check routines spell out in more
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detail the assumptions and invariants underlying the algorithms.
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*/
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#if MALLOC_DEBUG
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#include <assert.h>
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#else
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#define assert(x) ((void)0)
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#endif
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|
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/*
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INTERNAL_SIZE_T is the word-size used for internal bookkeeping
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of chunk sizes. On a 64-bit machine, you can reduce malloc
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overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int'
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at the expense of not being able to handle requests greater than
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2^31. This limitation is hardly ever a concern; you are encouraged
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to set this. However, the default version is the same as size_t.
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*/
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#ifndef INTERNAL_SIZE_T
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#define INTERNAL_SIZE_T size_t
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#endif
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|
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/*
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REALLOC_ZERO_BYTES_FREES should be set if a call to
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realloc with zero bytes should be the same as a call to free.
|
||
Some people think it should. Otherwise, since this malloc
|
||
returns a unique pointer for malloc(0), so does realloc(p, 0).
|
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*/
|
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|
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|
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#define REALLOC_ZERO_BYTES_FREES
|
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|
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|
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/*
|
||
HAVE_MEMCPY should be defined if you are not otherwise using
|
||
ANSI STD C, but still have memcpy and memset in your C library
|
||
and want to use them in calloc and realloc. Otherwise simple
|
||
macro versions are defined here.
|
||
|
||
USE_MEMCPY should be defined as 1 if you actually want to
|
||
have memset and memcpy called. People report that the macro
|
||
versions are often enough faster than libc versions on many
|
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systems that it is better to use them.
|
||
|
||
*/
|
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|
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#define HAVE_MEMCPY 1
|
||
|
||
#ifndef USE_MEMCPY
|
||
#ifdef HAVE_MEMCPY
|
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#define USE_MEMCPY 1
|
||
#else
|
||
#define USE_MEMCPY 0
|
||
#endif
|
||
#endif
|
||
|
||
#if (__STD_C || defined(HAVE_MEMCPY))
|
||
|
||
#if __STD_C
|
||
void* memset(void*, int, size_t);
|
||
void* memcpy(void*, const void*, size_t);
|
||
#else
|
||
Void_t* memset();
|
||
Void_t* memcpy();
|
||
#endif
|
||
#endif
|
||
|
||
#if USE_MEMCPY
|
||
|
||
/* The following macros are only invoked with (2n+1)-multiples of
|
||
INTERNAL_SIZE_T units, with a positive integer n. This is exploited
|
||
for fast inline execution when n is small. */
|
||
|
||
#define MALLOC_ZERO(charp, nbytes) \
|
||
do { \
|
||
INTERNAL_SIZE_T mzsz = (nbytes); \
|
||
if(mzsz <= 9*sizeof(mzsz)) { \
|
||
INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp); \
|
||
if(mzsz >= 5*sizeof(mzsz)) { *mz++ = 0; \
|
||
*mz++ = 0; \
|
||
if(mzsz >= 7*sizeof(mzsz)) { *mz++ = 0; \
|
||
*mz++ = 0; \
|
||
if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0; \
|
||
*mz++ = 0; }}} \
|
||
*mz++ = 0; \
|
||
*mz++ = 0; \
|
||
*mz = 0; \
|
||
} else memset((charp), 0, mzsz); \
|
||
} while(0)
|
||
|
||
#define MALLOC_COPY(dest,src,nbytes) \
|
||
do { \
|
||
INTERNAL_SIZE_T mcsz = (nbytes); \
|
||
if(mcsz <= 9*sizeof(mcsz)) { \
|
||
INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src); \
|
||
INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest); \
|
||
if(mcsz >= 5*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
|
||
*mcdst++ = *mcsrc++; \
|
||
if(mcsz >= 7*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
|
||
*mcdst++ = *mcsrc++; \
|
||
if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++; \
|
||
*mcdst++ = *mcsrc++; }}} \
|
||
*mcdst++ = *mcsrc++; \
|
||
*mcdst++ = *mcsrc++; \
|
||
*mcdst = *mcsrc ; \
|
||
} else memcpy(dest, src, mcsz); \
|
||
} while(0)
|
||
|
||
#else /* !USE_MEMCPY */
|
||
|
||
/* Use Duff's device for good zeroing/copying performance. */
|
||
|
||
#define MALLOC_ZERO(charp, nbytes) \
|
||
do { \
|
||
INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp); \
|
||
long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
|
||
if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
|
||
switch (mctmp) { \
|
||
case 0: for(;;) { *mzp++ = 0; \
|
||
case 7: *mzp++ = 0; \
|
||
case 6: *mzp++ = 0; \
|
||
case 5: *mzp++ = 0; \
|
||
case 4: *mzp++ = 0; \
|
||
case 3: *mzp++ = 0; \
|
||
case 2: *mzp++ = 0; \
|
||
case 1: *mzp++ = 0; if(mcn <= 0) break; mcn--; } \
|
||
} \
|
||
} while(0)
|
||
|
||
#define MALLOC_COPY(dest,src,nbytes) \
|
||
do { \
|
||
INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src; \
|
||
INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest; \
|
||
long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
|
||
if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
|
||
switch (mctmp) { \
|
||
case 0: for(;;) { *mcdst++ = *mcsrc++; \
|
||
case 7: *mcdst++ = *mcsrc++; \
|
||
case 6: *mcdst++ = *mcsrc++; \
|
||
case 5: *mcdst++ = *mcsrc++; \
|
||
case 4: *mcdst++ = *mcsrc++; \
|
||
case 3: *mcdst++ = *mcsrc++; \
|
||
case 2: *mcdst++ = *mcsrc++; \
|
||
case 1: *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; } \
|
||
} \
|
||
} while(0)
|
||
|
||
#endif
|
||
|
||
|
||
#ifndef LACKS_UNISTD_H
|
||
# include <unistd.h>
|
||
#endif
|
||
|
||
/*
|
||
Define HAVE_MMAP to optionally make malloc() use mmap() to
|
||
allocate very large blocks. These will be returned to the
|
||
operating system immediately after a free().
|
||
*/
|
||
|
||
#ifndef HAVE_MMAP
|
||
# ifdef _POSIX_MAPPED_FILES
|
||
# define HAVE_MMAP 1
|
||
# endif
|
||
#endif
|
||
|
||
/*
|
||
Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
|
||
large blocks. This is currently only possible on Linux with
|
||
kernel versions newer than 1.3.77.
|
||
*/
|
||
|
||
#ifndef HAVE_MREMAP
|
||
#define HAVE_MREMAP defined(__linux__) && !defined(__arm__)
|
||
#endif
|
||
|
||
#if HAVE_MMAP
|
||
|
||
#include <unistd.h>
|
||
#include <fcntl.h>
|
||
#include <sys/mman.h>
|
||
|
||
#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
|
||
#define MAP_ANONYMOUS MAP_ANON
|
||
#endif
|
||
|
||
#ifndef MAP_NORESERVE
|
||
# ifdef MAP_AUTORESRV
|
||
# define MAP_NORESERVE MAP_AUTORESRV
|
||
# else
|
||
# define MAP_NORESERVE 0
|
||
# endif
|
||
#endif
|
||
|
||
#endif /* HAVE_MMAP */
|
||
|
||
/*
|
||
Access to system page size. To the extent possible, this malloc
|
||
manages memory from the system in page-size units.
|
||
|
||
The following mechanics for getpagesize were adapted from
|
||
bsd/gnu getpagesize.h
|
||
*/
|
||
|
||
#ifndef malloc_getpagesize
|
||
# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */
|
||
# ifndef _SC_PAGE_SIZE
|
||
# define _SC_PAGE_SIZE _SC_PAGESIZE
|
||
# endif
|
||
# endif
|
||
# ifdef _SC_PAGE_SIZE
|
||
# define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
|
||
# else
|
||
# if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE)
|
||
extern size_t getpagesize();
|
||
# define malloc_getpagesize getpagesize()
|
||
# else
|
||
# include <sys/param.h>
|
||
# ifdef EXEC_PAGESIZE
|
||
# define malloc_getpagesize EXEC_PAGESIZE
|
||
# else
|
||
# ifdef NBPG
|
||
# ifndef CLSIZE
|
||
# define malloc_getpagesize NBPG
|
||
# else
|
||
# define malloc_getpagesize (NBPG * CLSIZE)
|
||
# endif
|
||
# else
|
||
# ifdef NBPC
|
||
# define malloc_getpagesize NBPC
|
||
# else
|
||
# ifdef PAGESIZE
|
||
# define malloc_getpagesize PAGESIZE
|
||
# else
|
||
# define malloc_getpagesize (4096) /* just guess */
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
|
||
This version of malloc supports the standard SVID/XPG mallinfo
|
||
routine that returns a struct containing the same kind of
|
||
information you can get from malloc_stats. It should work on
|
||
any SVID/XPG compliant system that has a /usr/include/malloc.h
|
||
defining struct mallinfo. (If you'd like to install such a thing
|
||
yourself, cut out the preliminary declarations as described above
|
||
and below and save them in a malloc.h file. But there's no
|
||
compelling reason to bother to do this.)
|
||
|
||
The main declaration needed is the mallinfo struct that is returned
|
||
(by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a
|
||
bunch of fields, most of which are not even meaningful in this
|
||
version of malloc. Some of these fields are are instead filled by
|
||
mallinfo() with other numbers that might possibly be of interest.
|
||
|
||
HAVE_USR_INCLUDE_MALLOC_H should be set if you have a
|
||
/usr/include/malloc.h file that includes a declaration of struct
|
||
mallinfo. If so, it is included; else an SVID2/XPG2 compliant
|
||
version is declared below. These must be precisely the same for
|
||
mallinfo() to work.
|
||
|
||
*/
|
||
|
||
/* #define HAVE_USR_INCLUDE_MALLOC_H */
|
||
|
||
#if HAVE_USR_INCLUDE_MALLOC_H
|
||
# include "/usr/include/malloc.h"
|
||
#else
|
||
# ifdef _LIBC
|
||
# include "malloc.h"
|
||
# else
|
||
# include "ptmalloc.h"
|
||
# endif
|
||
#endif
|
||
|
||
|
||
|
||
#ifndef DEFAULT_TRIM_THRESHOLD
|
||
#define DEFAULT_TRIM_THRESHOLD (128 * 1024)
|
||
#endif
|
||
|
||
/*
|
||
M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
|
||
to keep before releasing via malloc_trim in free().
|
||
|
||
Automatic trimming is mainly useful in long-lived programs.
|
||
Because trimming via sbrk can be slow on some systems, and can
|
||
sometimes be wasteful (in cases where programs immediately
|
||
afterward allocate more large chunks) the value should be high
|
||
enough so that your overall system performance would improve by
|
||
releasing.
|
||
|
||
The trim threshold and the mmap control parameters (see below)
|
||
can be traded off with one another. Trimming and mmapping are
|
||
two different ways of releasing unused memory back to the
|
||
system. Between these two, it is often possible to keep
|
||
system-level demands of a long-lived program down to a bare
|
||
minimum. For example, in one test suite of sessions measuring
|
||
the XF86 X server on Linux, using a trim threshold of 128K and a
|
||
mmap threshold of 192K led to near-minimal long term resource
|
||
consumption.
|
||
|
||
If you are using this malloc in a long-lived program, it should
|
||
pay to experiment with these values. As a rough guide, you
|
||
might set to a value close to the average size of a process
|
||
(program) running on your system. Releasing this much memory
|
||
would allow such a process to run in memory. Generally, it's
|
||
worth it to tune for trimming rather than memory mapping when a
|
||
program undergoes phases where several large chunks are
|
||
allocated and released in ways that can reuse each other's
|
||
storage, perhaps mixed with phases where there are no such
|
||
chunks at all. And in well-behaved long-lived programs,
|
||
controlling release of large blocks via trimming versus mapping
|
||
is usually faster.
|
||
|
||
However, in most programs, these parameters serve mainly as
|
||
protection against the system-level effects of carrying around
|
||
massive amounts of unneeded memory. Since frequent calls to
|
||
sbrk, mmap, and munmap otherwise degrade performance, the default
|
||
parameters are set to relatively high values that serve only as
|
||
safeguards.
|
||
|
||
The default trim value is high enough to cause trimming only in
|
||
fairly extreme (by current memory consumption standards) cases.
|
||
It must be greater than page size to have any useful effect. To
|
||
disable trimming completely, you can set to (unsigned long)(-1);
|
||
|
||
|
||
*/
|
||
|
||
|
||
#ifndef DEFAULT_TOP_PAD
|
||
#define DEFAULT_TOP_PAD (0)
|
||
#endif
|
||
|
||
/*
|
||
M_TOP_PAD is the amount of extra `padding' space to allocate or
|
||
retain whenever sbrk is called. It is used in two ways internally:
|
||
|
||
* When sbrk is called to extend the top of the arena to satisfy
|
||
a new malloc request, this much padding is added to the sbrk
|
||
request.
|
||
|
||
* When malloc_trim is called automatically from free(),
|
||
it is used as the `pad' argument.
|
||
|
||
In both cases, the actual amount of padding is rounded
|
||
so that the end of the arena is always a system page boundary.
|
||
|
||
The main reason for using padding is to avoid calling sbrk so
|
||
often. Having even a small pad greatly reduces the likelihood
|
||
that nearly every malloc request during program start-up (or
|
||
after trimming) will invoke sbrk, which needlessly wastes
|
||
time.
|
||
|
||
Automatic rounding-up to page-size units is normally sufficient
|
||
to avoid measurable overhead, so the default is 0. However, in
|
||
systems where sbrk is relatively slow, it can pay to increase
|
||
this value, at the expense of carrying around more memory than
|
||
the program needs.
|
||
|
||
*/
|
||
|
||
|
||
#ifndef DEFAULT_MMAP_THRESHOLD
|
||
#define DEFAULT_MMAP_THRESHOLD (128 * 1024)
|
||
#endif
|
||
|
||
/*
|
||
|
||
M_MMAP_THRESHOLD is the request size threshold for using mmap()
|
||
to service a request. Requests of at least this size that cannot
|
||
be allocated using already-existing space will be serviced via mmap.
|
||
(If enough normal freed space already exists it is used instead.)
|
||
|
||
Using mmap segregates relatively large chunks of memory so that
|
||
they can be individually obtained and released from the host
|
||
system. A request serviced through mmap is never reused by any
|
||
other request (at least not directly; the system may just so
|
||
happen to remap successive requests to the same locations).
|
||
|
||
Segregating space in this way has the benefit that mmapped space
|
||
can ALWAYS be individually released back to the system, which
|
||
helps keep the system level memory demands of a long-lived
|
||
program low. Mapped memory can never become `locked' between
|
||
other chunks, as can happen with normally allocated chunks, which
|
||
menas that even trimming via malloc_trim would not release them.
|
||
|
||
However, it has the disadvantages that:
|
||
|
||
1. The space cannot be reclaimed, consolidated, and then
|
||
used to service later requests, as happens with normal chunks.
|
||
2. It can lead to more wastage because of mmap page alignment
|
||
requirements
|
||
3. It causes malloc performance to be more dependent on host
|
||
system memory management support routines which may vary in
|
||
implementation quality and may impose arbitrary
|
||
limitations. Generally, servicing a request via normal
|
||
malloc steps is faster than going through a system's mmap.
|
||
|
||
All together, these considerations should lead you to use mmap
|
||
only for relatively large requests.
|
||
|
||
|
||
*/
|
||
|
||
|
||
|
||
#ifndef DEFAULT_MMAP_MAX
|
||
#if HAVE_MMAP
|
||
#define DEFAULT_MMAP_MAX (1024)
|
||
#else
|
||
#define DEFAULT_MMAP_MAX (0)
|
||
#endif
|
||
#endif
|
||
|
||
/*
|
||
M_MMAP_MAX is the maximum number of requests to simultaneously
|
||
service using mmap. This parameter exists because:
|
||
|
||
1. Some systems have a limited number of internal tables for
|
||
use by mmap.
|
||
2. In most systems, overreliance on mmap can degrade overall
|
||
performance.
|
||
3. If a program allocates many large regions, it is probably
|
||
better off using normal sbrk-based allocation routines that
|
||
can reclaim and reallocate normal heap memory. Using a
|
||
small value allows transition into this mode after the
|
||
first few allocations.
|
||
|
||
Setting to 0 disables all use of mmap. If HAVE_MMAP is not set,
|
||
the default value is 0, and attempts to set it to non-zero values
|
||
in mallopt will fail.
|
||
*/
|
||
|
||
|
||
|
||
#ifndef DEFAULT_CHECK_ACTION
|
||
#define DEFAULT_CHECK_ACTION 1
|
||
#endif
|
||
|
||
/* What to do if the standard debugging hooks are in place and a
|
||
corrupt pointer is detected: do nothing (0), print an error message
|
||
(1), or call abort() (2). */
|
||
|
||
|
||
|
||
#define HEAP_MIN_SIZE (32*1024)
|
||
#define HEAP_MAX_SIZE (1024*1024) /* must be a power of two */
|
||
|
||
/* HEAP_MIN_SIZE and HEAP_MAX_SIZE limit the size of mmap()ed heaps
|
||
that are dynamically created for multi-threaded programs. The
|
||
maximum size must be a power of two, for fast determination of
|
||
which heap belongs to a chunk. It should be much larger than
|
||
the mmap threshold, so that requests with a size just below that
|
||
threshold can be fulfilled without creating too many heaps.
|
||
*/
|
||
|
||
|
||
|
||
#ifndef THREAD_STATS
|
||
#define THREAD_STATS 0
|
||
#endif
|
||
|
||
/* If THREAD_STATS is non-zero, some statistics on mutex locking are
|
||
computed. */
|
||
|
||
|
||
/*
|
||
|
||
Special defines for the Linux/GNU C library.
|
||
|
||
*/
|
||
|
||
|
||
#ifdef _LIBC
|
||
|
||
#if __STD_C
|
||
|
||
Void_t * __default_morecore (ptrdiff_t);
|
||
Void_t *(*__morecore)(ptrdiff_t) = __default_morecore;
|
||
|
||
#else
|
||
|
||
Void_t * __default_morecore ();
|
||
Void_t *(*__morecore)() = __default_morecore;
|
||
|
||
#endif
|
||
|
||
#define MORECORE (*__morecore)
|
||
#define MORECORE_FAILURE 0
|
||
#define MORECORE_CLEARS 1
|
||
#define mmap __mmap
|
||
#define munmap __munmap
|
||
#define mremap __mremap
|
||
#define mprotect __mprotect
|
||
#undef malloc_getpagesize
|
||
#define malloc_getpagesize __getpagesize()
|
||
|
||
#else /* _LIBC */
|
||
|
||
#if __STD_C
|
||
extern Void_t* sbrk(ptrdiff_t);
|
||
#else
|
||
extern Void_t* sbrk();
|
||
#endif
|
||
|
||
#ifndef MORECORE
|
||
#define MORECORE sbrk
|
||
#endif
|
||
|
||
#ifndef MORECORE_FAILURE
|
||
#define MORECORE_FAILURE -1
|
||
#endif
|
||
|
||
#ifndef MORECORE_CLEARS
|
||
#define MORECORE_CLEARS 1
|
||
#endif
|
||
|
||
#endif /* _LIBC */
|
||
|
||
#ifdef _LIBC
|
||
|
||
#define cALLOc __libc_calloc
|
||
#define fREe __libc_free
|
||
#define mALLOc __libc_malloc
|
||
#define mEMALIGn __libc_memalign
|
||
#define rEALLOc __libc_realloc
|
||
#define vALLOc __libc_valloc
|
||
#define pvALLOc __libc_pvalloc
|
||
#define mALLINFo __libc_mallinfo
|
||
#define mALLOPt __libc_mallopt
|
||
#define mALLOC_STATs __malloc_stats
|
||
#define mALLOC_USABLE_SIZe __malloc_usable_size
|
||
#define mALLOC_TRIm __malloc_trim
|
||
#define mALLOC_GET_STATe __malloc_get_state
|
||
#define mALLOC_SET_STATe __malloc_set_state
|
||
|
||
#else
|
||
|
||
#define cALLOc calloc
|
||
#define fREe free
|
||
#define mALLOc malloc
|
||
#define mEMALIGn memalign
|
||
#define rEALLOc realloc
|
||
#define vALLOc valloc
|
||
#define pvALLOc pvalloc
|
||
#define mALLINFo mallinfo
|
||
#define mALLOPt mallopt
|
||
#define mALLOC_STATs malloc_stats
|
||
#define mALLOC_USABLE_SIZe malloc_usable_size
|
||
#define mALLOC_TRIm malloc_trim
|
||
#define mALLOC_GET_STATe malloc_get_state
|
||
#define mALLOC_SET_STATe malloc_set_state
|
||
|
||
#endif
|
||
|
||
/* Public routines */
|
||
|
||
#if __STD_C
|
||
|
||
#ifndef _LIBC
|
||
void ptmalloc_init(void);
|
||
#endif
|
||
Void_t* mALLOc(size_t);
|
||
void fREe(Void_t*);
|
||
Void_t* rEALLOc(Void_t*, size_t);
|
||
Void_t* mEMALIGn(size_t, size_t);
|
||
Void_t* vALLOc(size_t);
|
||
Void_t* pvALLOc(size_t);
|
||
Void_t* cALLOc(size_t, size_t);
|
||
void cfree(Void_t*);
|
||
int mALLOC_TRIm(size_t);
|
||
size_t mALLOC_USABLE_SIZe(Void_t*);
|
||
void mALLOC_STATs(void);
|
||
int mALLOPt(int, int);
|
||
struct mallinfo mALLINFo(void);
|
||
Void_t* mALLOC_GET_STATe(void);
|
||
int mALLOC_SET_STATe(Void_t*);
|
||
|
||
#else /* !__STD_C */
|
||
|
||
#ifndef _LIBC
|
||
void ptmalloc_init();
|
||
#endif
|
||
Void_t* mALLOc();
|
||
void fREe();
|
||
Void_t* rEALLOc();
|
||
Void_t* mEMALIGn();
|
||
Void_t* vALLOc();
|
||
Void_t* pvALLOc();
|
||
Void_t* cALLOc();
|
||
void cfree();
|
||
int mALLOC_TRIm();
|
||
size_t mALLOC_USABLE_SIZe();
|
||
void mALLOC_STATs();
|
||
int mALLOPt();
|
||
struct mallinfo mALLINFo();
|
||
Void_t* mALLOC_GET_STATe();
|
||
int mALLOC_SET_STATe();
|
||
|
||
#endif /* __STD_C */
|
||
|
||
|
||
#ifdef __cplusplus
|
||
}; /* end of extern "C" */
|
||
#endif
|
||
|
||
#if !defined(NO_THREADS) && !HAVE_MMAP
|
||
"Can't have threads support without mmap"
|
||
#endif
|
||
|
||
|
||
/*
|
||
Type declarations
|
||
*/
|
||
|
||
|
||
struct malloc_chunk
|
||
{
|
||
INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */
|
||
INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */
|
||
struct malloc_chunk* fd; /* double links -- used only if free. */
|
||
struct malloc_chunk* bk;
|
||
};
|
||
|
||
typedef struct malloc_chunk* mchunkptr;
|
||
|
||
/*
|
||
|
||
malloc_chunk details:
|
||
|
||
(The following includes lightly edited explanations by Colin Plumb.)
|
||
|
||
Chunks of memory are maintained using a `boundary tag' method as
|
||
described in e.g., Knuth or Standish. (See the paper by Paul
|
||
Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
|
||
survey of such techniques.) Sizes of free chunks are stored both
|
||
in the front of each chunk and at the end. This makes
|
||
consolidating fragmented chunks into bigger chunks very fast. The
|
||
size fields also hold bits representing whether chunks are free or
|
||
in use.
|
||
|
||
An allocated chunk looks like this:
|
||
|
||
|
||
chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of previous chunk, if allocated | |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of chunk, in bytes |P|
|
||
mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| User data starts here... .
|
||
. .
|
||
. (malloc_usable_space() bytes) .
|
||
. |
|
||
nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of chunk |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
|
||
|
||
Where "chunk" is the front of the chunk for the purpose of most of
|
||
the malloc code, but "mem" is the pointer that is returned to the
|
||
user. "Nextchunk" is the beginning of the next contiguous chunk.
|
||
|
||
Chunks always begin on even word boundaries, so the mem portion
|
||
(which is returned to the user) is also on an even word boundary, and
|
||
thus double-word aligned.
|
||
|
||
Free chunks are stored in circular doubly-linked lists, and look like this:
|
||
|
||
chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of previous chunk |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
`head:' | Size of chunk, in bytes |P|
|
||
mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Forward pointer to next chunk in list |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Back pointer to previous chunk in list |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Unused space (may be 0 bytes long) .
|
||
. .
|
||
. |
|
||
nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
`foot:' | Size of chunk, in bytes |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
|
||
The P (PREV_INUSE) bit, stored in the unused low-order bit of the
|
||
chunk size (which is always a multiple of two words), is an in-use
|
||
bit for the *previous* chunk. If that bit is *clear*, then the
|
||
word before the current chunk size contains the previous chunk
|
||
size, and can be used to find the front of the previous chunk.
|
||
(The very first chunk allocated always has this bit set,
|
||
preventing access to non-existent (or non-owned) memory.)
|
||
|
||
Note that the `foot' of the current chunk is actually represented
|
||
as the prev_size of the NEXT chunk. (This makes it easier to
|
||
deal with alignments etc).
|
||
|
||
The two exceptions to all this are
|
||
|
||
1. The special chunk `top', which doesn't bother using the
|
||
trailing size field since there is no
|
||
next contiguous chunk that would have to index off it. (After
|
||
initialization, `top' is forced to always exist. If it would
|
||
become less than MINSIZE bytes long, it is replenished via
|
||
malloc_extend_top.)
|
||
|
||
2. Chunks allocated via mmap, which have the second-lowest-order
|
||
bit (IS_MMAPPED) set in their size fields. Because they are
|
||
never merged or traversed from any other chunk, they have no
|
||
foot size or inuse information.
|
||
|
||
Available chunks are kept in any of several places (all declared below):
|
||
|
||
* `av': An array of chunks serving as bin headers for consolidated
|
||
chunks. Each bin is doubly linked. The bins are approximately
|
||
proportionally (log) spaced. There are a lot of these bins
|
||
(128). This may look excessive, but works very well in
|
||
practice. All procedures maintain the invariant that no
|
||
consolidated chunk physically borders another one. Chunks in
|
||
bins are kept in size order, with ties going to the
|
||
approximately least recently used chunk.
|
||
|
||
The chunks in each bin are maintained in decreasing sorted order by
|
||
size. This is irrelevant for the small bins, which all contain
|
||
the same-sized chunks, but facilitates best-fit allocation for
|
||
larger chunks. (These lists are just sequential. Keeping them in
|
||
order almost never requires enough traversal to warrant using
|
||
fancier ordered data structures.) Chunks of the same size are
|
||
linked with the most recently freed at the front, and allocations
|
||
are taken from the back. This results in LRU or FIFO allocation
|
||
order, which tends to give each chunk an equal opportunity to be
|
||
consolidated with adjacent freed chunks, resulting in larger free
|
||
chunks and less fragmentation.
|
||
|
||
* `top': The top-most available chunk (i.e., the one bordering the
|
||
end of available memory) is treated specially. It is never
|
||
included in any bin, is used only if no other chunk is
|
||
available, and is released back to the system if it is very
|
||
large (see M_TRIM_THRESHOLD).
|
||
|
||
* `last_remainder': A bin holding only the remainder of the
|
||
most recently split (non-top) chunk. This bin is checked
|
||
before other non-fitting chunks, so as to provide better
|
||
locality for runs of sequentially allocated chunks.
|
||
|
||
* Implicitly, through the host system's memory mapping tables.
|
||
If supported, requests greater than a threshold are usually
|
||
serviced via calls to mmap, and then later released via munmap.
|
||
|
||
*/
|
||
|
||
/*
|
||
Bins
|
||
|
||
The bins are an array of pairs of pointers serving as the
|
||
heads of (initially empty) doubly-linked lists of chunks, laid out
|
||
in a way so that each pair can be treated as if it were in a
|
||
malloc_chunk. (This way, the fd/bk offsets for linking bin heads
|
||
and chunks are the same).
|
||
|
||
Bins for sizes < 512 bytes contain chunks of all the same size, spaced
|
||
8 bytes apart. Larger bins are approximately logarithmically
|
||
spaced. (See the table below.)
|
||
|
||
Bin layout:
|
||
|
||
64 bins of size 8
|
||
32 bins of size 64
|
||
16 bins of size 512
|
||
8 bins of size 4096
|
||
4 bins of size 32768
|
||
2 bins of size 262144
|
||
1 bin of size what's left
|
||
|
||
There is actually a little bit of slop in the numbers in bin_index
|
||
for the sake of speed. This makes no difference elsewhere.
|
||
|
||
The special chunks `top' and `last_remainder' get their own bins,
|
||
(this is implemented via yet more trickery with the av array),
|
||
although `top' is never properly linked to its bin since it is
|
||
always handled specially.
|
||
|
||
*/
|
||
|
||
#define NAV 128 /* number of bins */
|
||
|
||
typedef struct malloc_chunk* mbinptr;
|
||
|
||
/* An arena is a configuration of malloc_chunks together with an array
|
||
of bins. With multiple threads, it must be locked via a mutex
|
||
before changing its data structures. One or more `heaps' are
|
||
associated with each arena, except for the main_arena, which is
|
||
associated only with the `main heap', i.e. the conventional free
|
||
store obtained with calls to MORECORE() (usually sbrk). The `av'
|
||
array is never mentioned directly in the code, but instead used via
|
||
bin access macros. */
|
||
|
||
typedef struct _arena {
|
||
mbinptr av[2*NAV + 2];
|
||
struct _arena *next;
|
||
size_t size;
|
||
#if THREAD_STATS
|
||
long stat_lock_direct, stat_lock_loop, stat_lock_wait;
|
||
#endif
|
||
mutex_t mutex;
|
||
} arena;
|
||
|
||
|
||
/* A heap is a single contiguous memory region holding (coalesceable)
|
||
malloc_chunks. It is allocated with mmap() and always starts at an
|
||
address aligned to HEAP_MAX_SIZE. Not used unless compiling for
|
||
multiple threads. */
|
||
|
||
typedef struct _heap_info {
|
||
arena *ar_ptr; /* Arena for this heap. */
|
||
struct _heap_info *prev; /* Previous heap. */
|
||
size_t size; /* Current size in bytes. */
|
||
size_t pad; /* Make sure the following data is properly aligned. */
|
||
} heap_info;
|
||
|
||
|
||
/*
|
||
Static functions (forward declarations)
|
||
*/
|
||
|
||
#if __STD_C
|
||
|
||
static void chunk_free(arena *ar_ptr, mchunkptr p) internal_function;
|
||
static mchunkptr chunk_alloc(arena *ar_ptr, INTERNAL_SIZE_T size)
|
||
internal_function;
|
||
static mchunkptr chunk_realloc(arena *ar_ptr, mchunkptr oldp,
|
||
INTERNAL_SIZE_T oldsize, INTERNAL_SIZE_T nb)
|
||
internal_function;
|
||
static mchunkptr chunk_align(arena *ar_ptr, INTERNAL_SIZE_T nb,
|
||
size_t alignment) internal_function;
|
||
static int main_trim(size_t pad) internal_function;
|
||
#ifndef NO_THREADS
|
||
static int heap_trim(heap_info *heap, size_t pad) internal_function;
|
||
#endif
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
static Void_t* malloc_check(size_t sz, const Void_t *caller);
|
||
static void free_check(Void_t* mem, const Void_t *caller);
|
||
static Void_t* realloc_check(Void_t* oldmem, size_t bytes,
|
||
const Void_t *caller);
|
||
static Void_t* memalign_check(size_t alignment, size_t bytes,
|
||
const Void_t *caller);
|
||
#ifndef NO_THREADS
|
||
static Void_t* malloc_starter(size_t sz, const Void_t *caller);
|
||
static void free_starter(Void_t* mem, const Void_t *caller);
|
||
static Void_t* malloc_atfork(size_t sz, const Void_t *caller);
|
||
static void free_atfork(Void_t* mem, const Void_t *caller);
|
||
#endif
|
||
#endif
|
||
|
||
#else
|
||
|
||
static void chunk_free();
|
||
static mchunkptr chunk_alloc();
|
||
static mchunkptr chunk_realloc();
|
||
static mchunkptr chunk_align();
|
||
static int main_trim();
|
||
#ifndef NO_THREADS
|
||
static int heap_trim();
|
||
#endif
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
static Void_t* malloc_check();
|
||
static void free_check();
|
||
static Void_t* realloc_check();
|
||
static Void_t* memalign_check();
|
||
#ifndef NO_THREADS
|
||
static Void_t* malloc_starter();
|
||
static void free_starter();
|
||
static Void_t* malloc_atfork();
|
||
static void free_atfork();
|
||
#endif
|
||
#endif
|
||
|
||
#endif
|
||
|
||
/* On some platforms we can compile internal, not exported functions better.
|
||
Let the environment provide a macro and define it to be empty if it
|
||
is not available. */
|
||
#ifndef internal_function
|
||
# define internal_function
|
||
#endif
|
||
|
||
|
||
|
||
/* sizes, alignments */
|
||
|
||
#define SIZE_SZ (sizeof(INTERNAL_SIZE_T))
|
||
#define MALLOC_ALIGNMENT (SIZE_SZ + SIZE_SZ)
|
||
#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1)
|
||
#define MINSIZE (sizeof(struct malloc_chunk))
|
||
|
||
/* conversion from malloc headers to user pointers, and back */
|
||
|
||
#define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ))
|
||
#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ))
|
||
|
||
/* pad request bytes into a usable size */
|
||
|
||
#define request2size(req) \
|
||
(((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \
|
||
(long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \
|
||
(((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK)))
|
||
|
||
/* Check if m has acceptable alignment */
|
||
|
||
#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0)
|
||
|
||
|
||
|
||
|
||
/*
|
||
Physical chunk operations
|
||
*/
|
||
|
||
|
||
/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */
|
||
|
||
#define PREV_INUSE 0x1
|
||
|
||
/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */
|
||
|
||
#define IS_MMAPPED 0x2
|
||
|
||
/* Bits to mask off when extracting size */
|
||
|
||
#define SIZE_BITS (PREV_INUSE|IS_MMAPPED)
|
||
|
||
|
||
/* Ptr to next physical malloc_chunk. */
|
||
|
||
#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) ))
|
||
|
||
/* Ptr to previous physical malloc_chunk */
|
||
|
||
#define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) ))
|
||
|
||
|
||
/* Treat space at ptr + offset as a chunk */
|
||
|
||
#define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s)))
|
||
|
||
|
||
|
||
|
||
/*
|
||
Dealing with use bits
|
||
*/
|
||
|
||
/* extract p's inuse bit */
|
||
|
||
#define inuse(p) \
|
||
((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE)
|
||
|
||
/* extract inuse bit of previous chunk */
|
||
|
||
#define prev_inuse(p) ((p)->size & PREV_INUSE)
|
||
|
||
/* check for mmap()'ed chunk */
|
||
|
||
#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED)
|
||
|
||
/* set/clear chunk as in use without otherwise disturbing */
|
||
|
||
#define set_inuse(p) \
|
||
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE
|
||
|
||
#define clear_inuse(p) \
|
||
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE)
|
||
|
||
/* check/set/clear inuse bits in known places */
|
||
|
||
#define inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE)
|
||
|
||
#define set_inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE)
|
||
|
||
#define clear_inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE))
|
||
|
||
|
||
|
||
|
||
/*
|
||
Dealing with size fields
|
||
*/
|
||
|
||
/* Get size, ignoring use bits */
|
||
|
||
#define chunksize(p) ((p)->size & ~(SIZE_BITS))
|
||
|
||
/* Set size at head, without disturbing its use bit */
|
||
|
||
#define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s)))
|
||
|
||
/* Set size/use ignoring previous bits in header */
|
||
|
||
#define set_head(p, s) ((p)->size = (s))
|
||
|
||
/* Set size at footer (only when chunk is not in use) */
|
||
|
||
#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s))
|
||
|
||
|
||
|
||
|
||
|
||
/* access macros */
|
||
|
||
#define bin_at(a, i) ((mbinptr)((char*)&(((a)->av)[2*(i) + 2]) - 2*SIZE_SZ))
|
||
#define init_bin(a, i) ((a)->av[2*i+2] = (a)->av[2*i+3] = bin_at((a), i))
|
||
#define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr)))
|
||
#define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr)))
|
||
|
||
/*
|
||
The first 2 bins are never indexed. The corresponding av cells are instead
|
||
used for bookkeeping. This is not to save space, but to simplify
|
||
indexing, maintain locality, and avoid some initialization tests.
|
||
*/
|
||
|
||
#define binblocks(a) (bin_at(a,0)->size)/* bitvector of nonempty blocks */
|
||
#define top(a) (bin_at(a,0)->fd) /* The topmost chunk */
|
||
#define last_remainder(a) (bin_at(a,1)) /* remainder from last split */
|
||
|
||
/*
|
||
Because top initially points to its own bin with initial
|
||
zero size, thus forcing extension on the first malloc request,
|
||
we avoid having any special code in malloc to check whether
|
||
it even exists yet. But we still need to in malloc_extend_top.
|
||
*/
|
||
|
||
#define initial_top(a) ((mchunkptr)bin_at(a, 0))
|
||
|
||
|
||
|
||
/* field-extraction macros */
|
||
|
||
#define first(b) ((b)->fd)
|
||
#define last(b) ((b)->bk)
|
||
|
||
/*
|
||
Indexing into bins
|
||
*/
|
||
|
||
#define bin_index(sz) \
|
||
(((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3):\
|
||
((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6):\
|
||
((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9):\
|
||
((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12):\
|
||
((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15):\
|
||
((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18):\
|
||
126)
|
||
/*
|
||
bins for chunks < 512 are all spaced 8 bytes apart, and hold
|
||
identically sized chunks. This is exploited in malloc.
|
||
*/
|
||
|
||
#define MAX_SMALLBIN 63
|
||
#define MAX_SMALLBIN_SIZE 512
|
||
#define SMALLBIN_WIDTH 8
|
||
|
||
#define smallbin_index(sz) (((unsigned long)(sz)) >> 3)
|
||
|
||
/*
|
||
Requests are `small' if both the corresponding and the next bin are small
|
||
*/
|
||
|
||
#define is_small_request(nb) ((nb) < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH)
|
||
|
||
|
||
|
||
/*
|
||
To help compensate for the large number of bins, a one-level index
|
||
structure is used for bin-by-bin searching. `binblocks' is a
|
||
one-word bitvector recording whether groups of BINBLOCKWIDTH bins
|
||
have any (possibly) non-empty bins, so they can be skipped over
|
||
all at once during during traversals. The bits are NOT always
|
||
cleared as soon as all bins in a block are empty, but instead only
|
||
when all are noticed to be empty during traversal in malloc.
|
||
*/
|
||
|
||
#define BINBLOCKWIDTH 4 /* bins per block */
|
||
|
||
/* bin<->block macros */
|
||
|
||
#define idx2binblock(ix) ((unsigned)1 << ((ix) / BINBLOCKWIDTH))
|
||
#define mark_binblock(a, ii) (binblocks(a) |= idx2binblock(ii))
|
||
#define clear_binblock(a, ii) (binblocks(a) &= ~(idx2binblock(ii)))
|
||
|
||
|
||
|
||
|
||
/* Static bookkeeping data */
|
||
|
||
/* Helper macro to initialize bins */
|
||
#define IAV(i) bin_at(&main_arena, i), bin_at(&main_arena, i)
|
||
|
||
static arena main_arena = {
|
||
{
|
||
0, 0,
|
||
IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7),
|
||
IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15),
|
||
IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23),
|
||
IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31),
|
||
IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39),
|
||
IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47),
|
||
IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55),
|
||
IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63),
|
||
IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71),
|
||
IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79),
|
||
IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87),
|
||
IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95),
|
||
IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103),
|
||
IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111),
|
||
IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119),
|
||
IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127)
|
||
},
|
||
&main_arena, /* next */
|
||
0, /* size */
|
||
#if THREAD_STATS
|
||
0, 0, 0, /* stat_lock_direct, stat_lock_loop, stat_lock_wait */
|
||
#endif
|
||
MUTEX_INITIALIZER /* mutex */
|
||
};
|
||
|
||
#undef IAV
|
||
|
||
/* Thread specific data */
|
||
|
||
#ifndef NO_THREADS
|
||
static tsd_key_t arena_key;
|
||
static mutex_t list_lock = MUTEX_INITIALIZER;
|
||
#endif
|
||
|
||
#if THREAD_STATS
|
||
static int stat_n_heaps = 0;
|
||
#define THREAD_STAT(x) x
|
||
#else
|
||
#define THREAD_STAT(x) do ; while(0)
|
||
#endif
|
||
|
||
/* variables holding tunable values */
|
||
|
||
static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD;
|
||
static unsigned long top_pad = DEFAULT_TOP_PAD;
|
||
static unsigned int n_mmaps_max = DEFAULT_MMAP_MAX;
|
||
static unsigned long mmap_threshold = DEFAULT_MMAP_THRESHOLD;
|
||
static int check_action = DEFAULT_CHECK_ACTION;
|
||
|
||
/* The first value returned from sbrk */
|
||
static char* sbrk_base = (char*)(-1);
|
||
|
||
/* The maximum memory obtained from system via sbrk */
|
||
static unsigned long max_sbrked_mem = 0;
|
||
|
||
/* The maximum via either sbrk or mmap (too difficult to track with threads) */
|
||
#ifdef NO_THREADS
|
||
static unsigned long max_total_mem = 0;
|
||
#endif
|
||
|
||
/* The total memory obtained from system via sbrk */
|
||
#define sbrked_mem (main_arena.size)
|
||
|
||
/* Tracking mmaps */
|
||
|
||
static unsigned int n_mmaps = 0;
|
||
static unsigned int max_n_mmaps = 0;
|
||
static unsigned long mmapped_mem = 0;
|
||
static unsigned long max_mmapped_mem = 0;
|
||
|
||
|
||
|
||
#ifndef _LIBC
|
||
#define weak_variable
|
||
#else
|
||
/* In GNU libc we want the hook variables to be weak definitions to
|
||
avoid a problem with Emacs. */
|
||
#define weak_variable weak_function
|
||
#endif
|
||
|
||
/* Already initialized? */
|
||
int __malloc_initialized = -1;
|
||
|
||
|
||
#ifndef NO_THREADS
|
||
|
||
/* The following two functions are registered via thread_atfork() to
|
||
make sure that the mutexes remain in a consistent state in the
|
||
fork()ed version of a thread. Also adapt the malloc and free hooks
|
||
temporarily, because the `atfork' handler mechanism may use
|
||
malloc/free internally (e.g. in LinuxThreads). */
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
static __malloc_ptr_t (*save_malloc_hook) __MALLOC_P ((size_t __size,
|
||
const __malloc_ptr_t));
|
||
static void (*save_free_hook) __MALLOC_P ((__malloc_ptr_t __ptr,
|
||
const __malloc_ptr_t));
|
||
static Void_t* save_arena;
|
||
#endif
|
||
|
||
static void
|
||
ptmalloc_lock_all __MALLOC_P((void))
|
||
{
|
||
arena *ar_ptr;
|
||
|
||
(void)mutex_lock(&list_lock);
|
||
for(ar_ptr = &main_arena;;) {
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
ar_ptr = ar_ptr->next;
|
||
if(ar_ptr == &main_arena) break;
|
||
}
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
save_malloc_hook = __malloc_hook;
|
||
save_free_hook = __free_hook;
|
||
__malloc_hook = malloc_atfork;
|
||
__free_hook = free_atfork;
|
||
/* Only the current thread may perform malloc/free calls now. */
|
||
tsd_getspecific(arena_key, save_arena);
|
||
tsd_setspecific(arena_key, (Void_t*)0);
|
||
#endif
|
||
}
|
||
|
||
static void
|
||
ptmalloc_unlock_all __MALLOC_P((void))
|
||
{
|
||
arena *ar_ptr;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
tsd_setspecific(arena_key, save_arena);
|
||
__malloc_hook = save_malloc_hook;
|
||
__free_hook = save_free_hook;
|
||
#endif
|
||
for(ar_ptr = &main_arena;;) {
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
ar_ptr = ar_ptr->next;
|
||
if(ar_ptr == &main_arena) break;
|
||
}
|
||
(void)mutex_unlock(&list_lock);
|
||
}
|
||
|
||
static void
|
||
ptmalloc_init_all __MALLOC_P((void))
|
||
{
|
||
arena *ar_ptr;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
tsd_setspecific(arena_key, save_arena);
|
||
__malloc_hook = save_malloc_hook;
|
||
__free_hook = save_free_hook;
|
||
#endif
|
||
for(ar_ptr = &main_arena;;) {
|
||
(void)mutex_init(&ar_ptr->mutex);
|
||
ar_ptr = ar_ptr->next;
|
||
if(ar_ptr == &main_arena) break;
|
||
}
|
||
(void)mutex_init(&list_lock);
|
||
}
|
||
|
||
#endif
|
||
|
||
/* Initialization routine. */
|
||
#if defined(_LIBC)
|
||
#if 0
|
||
static void ptmalloc_init __MALLOC_P ((void)) __attribute__ ((constructor));
|
||
#endif
|
||
|
||
static void
|
||
ptmalloc_init __MALLOC_P((void))
|
||
#else
|
||
void
|
||
ptmalloc_init __MALLOC_P((void))
|
||
#endif
|
||
{
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
const char* s;
|
||
#endif
|
||
|
||
if(__malloc_initialized >= 0) return;
|
||
__malloc_initialized = 0;
|
||
#ifndef NO_THREADS
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
/* With some threads implementations, creating thread-specific data
|
||
or initializing a mutex may call malloc() itself. Provide a
|
||
simple starter version (realloc() won't work). */
|
||
save_malloc_hook = __malloc_hook;
|
||
save_free_hook = __free_hook;
|
||
__malloc_hook = malloc_starter;
|
||
__free_hook = free_starter;
|
||
#endif
|
||
#ifdef _LIBC
|
||
/* Initialize the pthreads interface. */
|
||
if (__pthread_initialize != NULL)
|
||
__pthread_initialize();
|
||
#endif
|
||
mutex_init(&main_arena.mutex);
|
||
mutex_init(&list_lock);
|
||
tsd_key_create(&arena_key, NULL);
|
||
tsd_setspecific(arena_key, (Void_t *)&main_arena);
|
||
thread_atfork(ptmalloc_lock_all, ptmalloc_unlock_all, ptmalloc_init_all);
|
||
#endif /* !defined NO_THREADS */
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
if((s = getenv("MALLOC_TRIM_THRESHOLD_")))
|
||
mALLOPt(M_TRIM_THRESHOLD, atoi(s));
|
||
if((s = getenv("MALLOC_TOP_PAD_")))
|
||
mALLOPt(M_TOP_PAD, atoi(s));
|
||
if((s = getenv("MALLOC_MMAP_THRESHOLD_")))
|
||
mALLOPt(M_MMAP_THRESHOLD, atoi(s));
|
||
if((s = getenv("MALLOC_MMAP_MAX_")))
|
||
mALLOPt(M_MMAP_MAX, atoi(s));
|
||
s = getenv("MALLOC_CHECK_");
|
||
#ifndef NO_THREADS
|
||
__malloc_hook = save_malloc_hook;
|
||
__free_hook = save_free_hook;
|
||
#endif
|
||
if(s) {
|
||
if(s[0]) mALLOPt(M_CHECK_ACTION, (int)(s[0] - '0'));
|
||
__malloc_check_init();
|
||
}
|
||
if(__malloc_initialize_hook != NULL)
|
||
(*__malloc_initialize_hook)();
|
||
#endif
|
||
__malloc_initialized = 1;
|
||
}
|
||
|
||
/* There are platforms (e.g. Hurd) with a link-time hook mechanism. */
|
||
#ifdef thread_atfork_static
|
||
thread_atfork_static(ptmalloc_lock_all, ptmalloc_unlock_all, \
|
||
ptmalloc_init_all)
|
||
#endif
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
|
||
/* Hooks for debugging versions. The initial hooks just call the
|
||
initialization routine, then do the normal work. */
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
malloc_hook_ini(size_t sz, const __malloc_ptr_t caller)
|
||
#else
|
||
malloc_hook_ini(sz, caller)
|
||
size_t sz; const __malloc_ptr_t caller;
|
||
#endif
|
||
{
|
||
__malloc_hook = NULL;
|
||
ptmalloc_init();
|
||
return mALLOc(sz);
|
||
}
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
realloc_hook_ini(Void_t* ptr, size_t sz, const __malloc_ptr_t caller)
|
||
#else
|
||
realloc_hook_ini(ptr, sz, caller)
|
||
Void_t* ptr; size_t sz; const __malloc_ptr_t caller;
|
||
#endif
|
||
{
|
||
__malloc_hook = NULL;
|
||
__realloc_hook = NULL;
|
||
ptmalloc_init();
|
||
return rEALLOc(ptr, sz);
|
||
}
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
memalign_hook_ini(size_t sz, size_t alignment, const __malloc_ptr_t caller)
|
||
#else
|
||
memalign_hook_ini(sz, alignment, caller)
|
||
size_t sz; size_t alignment; const __malloc_ptr_t caller;
|
||
#endif
|
||
{
|
||
__memalign_hook = NULL;
|
||
ptmalloc_init();
|
||
return mEMALIGn(sz, alignment);
|
||
}
|
||
|
||
void weak_variable (*__malloc_initialize_hook) __MALLOC_P ((void)) = NULL;
|
||
void weak_variable (*__free_hook) __MALLOC_P ((__malloc_ptr_t __ptr,
|
||
const __malloc_ptr_t)) = NULL;
|
||
__malloc_ptr_t weak_variable (*__malloc_hook)
|
||
__MALLOC_P ((size_t __size, const __malloc_ptr_t)) = malloc_hook_ini;
|
||
__malloc_ptr_t weak_variable (*__realloc_hook)
|
||
__MALLOC_P ((__malloc_ptr_t __ptr, size_t __size, const __malloc_ptr_t))
|
||
= realloc_hook_ini;
|
||
__malloc_ptr_t weak_variable (*__memalign_hook)
|
||
__MALLOC_P ((size_t __size, size_t __alignment, const __malloc_ptr_t))
|
||
= memalign_hook_ini;
|
||
void weak_variable (*__after_morecore_hook) __MALLOC_P ((void)) = NULL;
|
||
|
||
/* Whether we are using malloc checking. */
|
||
static int using_malloc_checking;
|
||
|
||
/* A flag that is set by malloc_set_state, to signal that malloc checking
|
||
must not be enabled on the request from the user (via the MALLOC_CHECK_
|
||
environment variable). It is reset by __malloc_check_init to tell
|
||
malloc_set_state that the user has requested malloc checking.
|
||
|
||
The purpose of this flag is to make sure that malloc checking is not
|
||
enabled when the heap to be restored was constructed without malloc
|
||
checking, and thus does not contain the required magic bytes.
|
||
Otherwise the heap would be corrupted by calls to free and realloc. If
|
||
it turns out that the heap was created with malloc checking and the
|
||
user has requested it malloc_set_state just calls __malloc_check_init
|
||
again to enable it. On the other hand, reusing such a heap without
|
||
further malloc checking is safe. */
|
||
static int disallow_malloc_check;
|
||
|
||
/* Activate a standard set of debugging hooks. */
|
||
void
|
||
__malloc_check_init()
|
||
{
|
||
if (disallow_malloc_check) {
|
||
disallow_malloc_check = 0;
|
||
return;
|
||
}
|
||
using_malloc_checking = 1;
|
||
__malloc_hook = malloc_check;
|
||
__free_hook = free_check;
|
||
__realloc_hook = realloc_check;
|
||
__memalign_hook = memalign_check;
|
||
if(check_action == 1)
|
||
fprintf(stderr, "malloc: using debugging hooks\n");
|
||
}
|
||
|
||
#endif
|
||
|
||
|
||
|
||
|
||
|
||
/* Routines dealing with mmap(). */
|
||
|
||
#if HAVE_MMAP
|
||
|
||
#ifndef MAP_ANONYMOUS
|
||
|
||
static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */
|
||
|
||
#define MMAP(addr, size, prot, flags) ((dev_zero_fd < 0) ? \
|
||
(dev_zero_fd = open("/dev/zero", O_RDWR), \
|
||
mmap((addr), (size), (prot), (flags), dev_zero_fd, 0)) : \
|
||
mmap((addr), (size), (prot), (flags), dev_zero_fd, 0))
|
||
|
||
#else
|
||
|
||
#define MMAP(addr, size, prot, flags) \
|
||
(mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS, -1, 0))
|
||
|
||
#endif
|
||
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
/* This function is only called from one place, inline it. */
|
||
inline
|
||
#endif
|
||
static mchunkptr
|
||
internal_function
|
||
#if __STD_C
|
||
mmap_chunk(size_t size)
|
||
#else
|
||
mmap_chunk(size) size_t size;
|
||
#endif
|
||
{
|
||
size_t page_mask = malloc_getpagesize - 1;
|
||
mchunkptr p;
|
||
|
||
if(n_mmaps >= n_mmaps_max) return 0; /* too many regions */
|
||
|
||
/* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because
|
||
* there is no following chunk whose prev_size field could be used.
|
||
*/
|
||
size = (size + SIZE_SZ + page_mask) & ~page_mask;
|
||
|
||
p = (mchunkptr)MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE);
|
||
if(p == (mchunkptr) MAP_FAILED) return 0;
|
||
|
||
n_mmaps++;
|
||
if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps;
|
||
|
||
/* We demand that eight bytes into a page must be 8-byte aligned. */
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
|
||
/* The offset to the start of the mmapped region is stored
|
||
* in the prev_size field of the chunk; normally it is zero,
|
||
* but that can be changed in memalign().
|
||
*/
|
||
p->prev_size = 0;
|
||
set_head(p, size|IS_MMAPPED);
|
||
|
||
mmapped_mem += size;
|
||
if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
|
||
max_mmapped_mem = mmapped_mem;
|
||
#ifdef NO_THREADS
|
||
if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
|
||
max_total_mem = mmapped_mem + sbrked_mem;
|
||
#endif
|
||
return p;
|
||
}
|
||
|
||
#if __STD_C
|
||
static void munmap_chunk(mchunkptr p)
|
||
#else
|
||
static void munmap_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T size = chunksize(p);
|
||
int ret;
|
||
|
||
assert (chunk_is_mmapped(p));
|
||
assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
|
||
assert((n_mmaps > 0));
|
||
assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0);
|
||
|
||
n_mmaps--;
|
||
mmapped_mem -= (size + p->prev_size);
|
||
|
||
ret = munmap((char *)p - p->prev_size, size + p->prev_size);
|
||
|
||
/* munmap returns non-zero on failure */
|
||
assert(ret == 0);
|
||
}
|
||
|
||
#if HAVE_MREMAP
|
||
|
||
#if __STD_C
|
||
static mchunkptr mremap_chunk(mchunkptr p, size_t new_size)
|
||
#else
|
||
static mchunkptr mremap_chunk(p, new_size) mchunkptr p; size_t new_size;
|
||
#endif
|
||
{
|
||
size_t page_mask = malloc_getpagesize - 1;
|
||
INTERNAL_SIZE_T offset = p->prev_size;
|
||
INTERNAL_SIZE_T size = chunksize(p);
|
||
char *cp;
|
||
|
||
assert (chunk_is_mmapped(p));
|
||
assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
|
||
assert((n_mmaps > 0));
|
||
assert(((size + offset) & (malloc_getpagesize-1)) == 0);
|
||
|
||
/* Note the extra SIZE_SZ overhead as in mmap_chunk(). */
|
||
new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask;
|
||
|
||
cp = (char *)mremap((char *)p - offset, size + offset, new_size,
|
||
MREMAP_MAYMOVE);
|
||
|
||
if (cp == (char *)-1) return 0;
|
||
|
||
p = (mchunkptr)(cp + offset);
|
||
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
|
||
assert((p->prev_size == offset));
|
||
set_head(p, (new_size - offset)|IS_MMAPPED);
|
||
|
||
mmapped_mem -= size + offset;
|
||
mmapped_mem += new_size;
|
||
if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
|
||
max_mmapped_mem = mmapped_mem;
|
||
#ifdef NO_THREADS
|
||
if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
|
||
max_total_mem = mmapped_mem + sbrked_mem;
|
||
#endif
|
||
return p;
|
||
}
|
||
|
||
#endif /* HAVE_MREMAP */
|
||
|
||
#endif /* HAVE_MMAP */
|
||
|
||
|
||
|
||
/* Managing heaps and arenas (for concurrent threads) */
|
||
|
||
#ifndef NO_THREADS
|
||
|
||
/* Create a new heap. size is automatically rounded up to a multiple
|
||
of the page size. */
|
||
|
||
static heap_info *
|
||
internal_function
|
||
#if __STD_C
|
||
new_heap(size_t size)
|
||
#else
|
||
new_heap(size) size_t size;
|
||
#endif
|
||
{
|
||
size_t page_mask = malloc_getpagesize - 1;
|
||
char *p1, *p2;
|
||
unsigned long ul;
|
||
heap_info *h;
|
||
|
||
if(size+top_pad < HEAP_MIN_SIZE)
|
||
size = HEAP_MIN_SIZE;
|
||
else if(size+top_pad <= HEAP_MAX_SIZE)
|
||
size += top_pad;
|
||
else if(size > HEAP_MAX_SIZE)
|
||
return 0;
|
||
else
|
||
size = HEAP_MAX_SIZE;
|
||
size = (size + page_mask) & ~page_mask;
|
||
|
||
/* A memory region aligned to a multiple of HEAP_MAX_SIZE is needed.
|
||
No swap space needs to be reserved for the following large
|
||
mapping (on Linux, this is the case for all non-writable mappings
|
||
anyway). */
|
||
p1 = (char *)MMAP(0, HEAP_MAX_SIZE<<1, PROT_NONE, MAP_PRIVATE|MAP_NORESERVE);
|
||
if(p1 == MAP_FAILED)
|
||
return 0;
|
||
p2 = (char *)(((unsigned long)p1 + HEAP_MAX_SIZE) & ~(HEAP_MAX_SIZE-1));
|
||
ul = p2 - p1;
|
||
munmap(p1, ul);
|
||
munmap(p2 + HEAP_MAX_SIZE, HEAP_MAX_SIZE - ul);
|
||
if(mprotect(p2, size, PROT_READ|PROT_WRITE) != 0) {
|
||
munmap(p2, HEAP_MAX_SIZE);
|
||
return 0;
|
||
}
|
||
h = (heap_info *)p2;
|
||
h->size = size;
|
||
THREAD_STAT(stat_n_heaps++);
|
||
return h;
|
||
}
|
||
|
||
/* Grow or shrink a heap. size is automatically rounded up to a
|
||
multiple of the page size if it is positive. */
|
||
|
||
static int
|
||
#if __STD_C
|
||
grow_heap(heap_info *h, long diff)
|
||
#else
|
||
grow_heap(h, diff) heap_info *h; long diff;
|
||
#endif
|
||
{
|
||
size_t page_mask = malloc_getpagesize - 1;
|
||
long new_size;
|
||
|
||
if(diff >= 0) {
|
||
diff = (diff + page_mask) & ~page_mask;
|
||
new_size = (long)h->size + diff;
|
||
if(new_size > HEAP_MAX_SIZE)
|
||
return -1;
|
||
if(mprotect((char *)h + h->size, diff, PROT_READ|PROT_WRITE) != 0)
|
||
return -2;
|
||
} else {
|
||
new_size = (long)h->size + diff;
|
||
if(new_size < (long)sizeof(*h))
|
||
return -1;
|
||
/* Try to re-map the extra heap space freshly to save memory, and
|
||
make it inaccessible. */
|
||
if((char *)MMAP((char *)h + new_size, -diff, PROT_NONE,
|
||
MAP_PRIVATE|MAP_FIXED) == (char *) MAP_FAILED)
|
||
return -2;
|
||
}
|
||
h->size = new_size;
|
||
return 0;
|
||
}
|
||
|
||
/* Delete a heap. */
|
||
|
||
#define delete_heap(heap) munmap((char*)(heap), HEAP_MAX_SIZE)
|
||
|
||
/* arena_get() acquires an arena and locks the corresponding mutex.
|
||
First, try the one last locked successfully by this thread. (This
|
||
is the common case and handled with a macro for speed.) Then, loop
|
||
once over the circularly linked list of arenas. If no arena is
|
||
readily available, create a new one. */
|
||
|
||
#define arena_get(ptr, size) do { \
|
||
Void_t *vptr = NULL; \
|
||
ptr = (arena *)tsd_getspecific(arena_key, vptr); \
|
||
if(ptr && !mutex_trylock(&ptr->mutex)) { \
|
||
THREAD_STAT(++(ptr->stat_lock_direct)); \
|
||
} else \
|
||
ptr = arena_get2(ptr, (size)); \
|
||
} while(0)
|
||
|
||
static arena *
|
||
internal_function
|
||
#if __STD_C
|
||
arena_get2(arena *a_tsd, size_t size)
|
||
#else
|
||
arena_get2(a_tsd, size) arena *a_tsd; size_t size;
|
||
#endif
|
||
{
|
||
arena *a;
|
||
heap_info *h;
|
||
char *ptr;
|
||
int i;
|
||
unsigned long misalign;
|
||
|
||
if(!a_tsd)
|
||
a = a_tsd = &main_arena;
|
||
else {
|
||
a = a_tsd->next;
|
||
if(!a) {
|
||
/* This can only happen while initializing the new arena. */
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
THREAD_STAT(++(main_arena.stat_lock_wait));
|
||
return &main_arena;
|
||
}
|
||
}
|
||
|
||
/* Check the global, circularly linked list for available arenas. */
|
||
repeat:
|
||
do {
|
||
if(!mutex_trylock(&a->mutex)) {
|
||
THREAD_STAT(++(a->stat_lock_loop));
|
||
tsd_setspecific(arena_key, (Void_t *)a);
|
||
return a;
|
||
}
|
||
a = a->next;
|
||
} while(a != a_tsd);
|
||
|
||
/* If not even the list_lock can be obtained, try again. This can
|
||
happen during `atfork', or for example on systems where thread
|
||
creation makes it temporarily impossible to obtain _any_
|
||
locks. */
|
||
if(mutex_trylock(&list_lock)) {
|
||
a = a_tsd;
|
||
goto repeat;
|
||
}
|
||
(void)mutex_unlock(&list_lock);
|
||
|
||
/* Nothing immediately available, so generate a new arena. */
|
||
h = new_heap(size + (sizeof(*h) + sizeof(*a) + MALLOC_ALIGNMENT));
|
||
if(!h)
|
||
return 0;
|
||
a = h->ar_ptr = (arena *)(h+1);
|
||
for(i=0; i<NAV; i++)
|
||
init_bin(a, i);
|
||
a->next = NULL;
|
||
a->size = h->size;
|
||
tsd_setspecific(arena_key, (Void_t *)a);
|
||
mutex_init(&a->mutex);
|
||
i = mutex_lock(&a->mutex); /* remember result */
|
||
|
||
/* Set up the top chunk, with proper alignment. */
|
||
ptr = (char *)(a + 1);
|
||
misalign = (unsigned long)chunk2mem(ptr) & MALLOC_ALIGN_MASK;
|
||
if (misalign > 0)
|
||
ptr += MALLOC_ALIGNMENT - misalign;
|
||
top(a) = (mchunkptr)ptr;
|
||
set_head(top(a), (((char*)h + h->size) - ptr) | PREV_INUSE);
|
||
|
||
/* Add the new arena to the list. */
|
||
(void)mutex_lock(&list_lock);
|
||
a->next = main_arena.next;
|
||
main_arena.next = a;
|
||
(void)mutex_unlock(&list_lock);
|
||
|
||
if(i) /* locking failed; keep arena for further attempts later */
|
||
return 0;
|
||
|
||
THREAD_STAT(++(a->stat_lock_loop));
|
||
return a;
|
||
}
|
||
|
||
/* find the heap and corresponding arena for a given ptr */
|
||
|
||
#define heap_for_ptr(ptr) \
|
||
((heap_info *)((unsigned long)(ptr) & ~(HEAP_MAX_SIZE-1)))
|
||
#define arena_for_ptr(ptr) \
|
||
(((mchunkptr)(ptr) < top(&main_arena) && (char *)(ptr) >= sbrk_base) ? \
|
||
&main_arena : heap_for_ptr(ptr)->ar_ptr)
|
||
|
||
#else /* defined(NO_THREADS) */
|
||
|
||
/* Without concurrent threads, there is only one arena. */
|
||
|
||
#define arena_get(ptr, sz) (ptr = &main_arena)
|
||
#define arena_for_ptr(ptr) (&main_arena)
|
||
|
||
#endif /* !defined(NO_THREADS) */
|
||
|
||
|
||
|
||
/*
|
||
Debugging support
|
||
*/
|
||
|
||
#if MALLOC_DEBUG
|
||
|
||
|
||
/*
|
||
These routines make a number of assertions about the states
|
||
of data structures that should be true at all times. If any
|
||
are not true, it's very likely that a user program has somehow
|
||
trashed memory. (It's also possible that there is a coding error
|
||
in malloc. In which case, please report it!)
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void do_check_chunk(arena *ar_ptr, mchunkptr p)
|
||
#else
|
||
static void do_check_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
|
||
|
||
/* No checkable chunk is mmapped */
|
||
assert(!chunk_is_mmapped(p));
|
||
|
||
#ifndef NO_THREADS
|
||
if(ar_ptr != &main_arena) {
|
||
heap_info *heap = heap_for_ptr(p);
|
||
assert(heap->ar_ptr == ar_ptr);
|
||
if(p != top(ar_ptr))
|
||
assert((char *)p + sz <= (char *)heap + heap->size);
|
||
else
|
||
assert((char *)p + sz == (char *)heap + heap->size);
|
||
return;
|
||
}
|
||
#endif
|
||
|
||
/* Check for legal address ... */
|
||
assert((char*)p >= sbrk_base);
|
||
if (p != top(ar_ptr))
|
||
assert((char*)p + sz <= (char*)top(ar_ptr));
|
||
else
|
||
assert((char*)p + sz <= sbrk_base + sbrked_mem);
|
||
|
||
}
|
||
|
||
|
||
#if __STD_C
|
||
static void do_check_free_chunk(arena *ar_ptr, mchunkptr p)
|
||
#else
|
||
static void do_check_free_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
|
||
mchunkptr next = chunk_at_offset(p, sz);
|
||
|
||
do_check_chunk(ar_ptr, p);
|
||
|
||
/* Check whether it claims to be free ... */
|
||
assert(!inuse(p));
|
||
|
||
/* Must have OK size and fields */
|
||
assert((long)sz >= (long)MINSIZE);
|
||
assert((sz & MALLOC_ALIGN_MASK) == 0);
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
/* ... matching footer field */
|
||
assert(next->prev_size == sz);
|
||
/* ... and is fully consolidated */
|
||
assert(prev_inuse(p));
|
||
assert (next == top(ar_ptr) || inuse(next));
|
||
|
||
/* ... and has minimally sane links */
|
||
assert(p->fd->bk == p);
|
||
assert(p->bk->fd == p);
|
||
}
|
||
|
||
#if __STD_C
|
||
static void do_check_inuse_chunk(arena *ar_ptr, mchunkptr p)
|
||
#else
|
||
static void do_check_inuse_chunk(ar_ptr, p) arena *ar_ptr; mchunkptr p;
|
||
#endif
|
||
{
|
||
mchunkptr next = next_chunk(p);
|
||
do_check_chunk(ar_ptr, p);
|
||
|
||
/* Check whether it claims to be in use ... */
|
||
assert(inuse(p));
|
||
|
||
/* ... whether its size is OK (it might be a fencepost) ... */
|
||
assert(chunksize(p) >= MINSIZE || next->size == (0|PREV_INUSE));
|
||
|
||
/* ... and is surrounded by OK chunks.
|
||
Since more things can be checked with free chunks than inuse ones,
|
||
if an inuse chunk borders them and debug is on, it's worth doing them.
|
||
*/
|
||
if (!prev_inuse(p))
|
||
{
|
||
mchunkptr prv = prev_chunk(p);
|
||
assert(next_chunk(prv) == p);
|
||
do_check_free_chunk(ar_ptr, prv);
|
||
}
|
||
if (next == top(ar_ptr))
|
||
{
|
||
assert(prev_inuse(next));
|
||
assert(chunksize(next) >= MINSIZE);
|
||
}
|
||
else if (!inuse(next))
|
||
do_check_free_chunk(ar_ptr, next);
|
||
|
||
}
|
||
|
||
#if __STD_C
|
||
static void do_check_malloced_chunk(arena *ar_ptr,
|
||
mchunkptr p, INTERNAL_SIZE_T s)
|
||
#else
|
||
static void do_check_malloced_chunk(ar_ptr, p, s)
|
||
arena *ar_ptr; mchunkptr p; INTERNAL_SIZE_T s;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
|
||
long room = sz - s;
|
||
|
||
do_check_inuse_chunk(ar_ptr, p);
|
||
|
||
/* Legal size ... */
|
||
assert((long)sz >= (long)MINSIZE);
|
||
assert((sz & MALLOC_ALIGN_MASK) == 0);
|
||
assert(room >= 0);
|
||
assert(room < (long)MINSIZE);
|
||
|
||
/* ... and alignment */
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
|
||
|
||
/* ... and was allocated at front of an available chunk */
|
||
assert(prev_inuse(p));
|
||
|
||
}
|
||
|
||
|
||
#define check_free_chunk(A,P) do_check_free_chunk(A,P)
|
||
#define check_inuse_chunk(A,P) do_check_inuse_chunk(A,P)
|
||
#define check_chunk(A,P) do_check_chunk(A,P)
|
||
#define check_malloced_chunk(A,P,N) do_check_malloced_chunk(A,P,N)
|
||
#else
|
||
#define check_free_chunk(A,P)
|
||
#define check_inuse_chunk(A,P)
|
||
#define check_chunk(A,P)
|
||
#define check_malloced_chunk(A,P,N)
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
Macro-based internal utilities
|
||
*/
|
||
|
||
|
||
/*
|
||
Linking chunks in bin lists.
|
||
Call these only with variables, not arbitrary expressions, as arguments.
|
||
*/
|
||
|
||
/*
|
||
Place chunk p of size s in its bin, in size order,
|
||
putting it ahead of others of same size.
|
||
*/
|
||
|
||
|
||
#define frontlink(A, P, S, IDX, BK, FD) \
|
||
{ \
|
||
if (S < MAX_SMALLBIN_SIZE) \
|
||
{ \
|
||
IDX = smallbin_index(S); \
|
||
mark_binblock(A, IDX); \
|
||
BK = bin_at(A, IDX); \
|
||
FD = BK->fd; \
|
||
P->bk = BK; \
|
||
P->fd = FD; \
|
||
FD->bk = BK->fd = P; \
|
||
} \
|
||
else \
|
||
{ \
|
||
IDX = bin_index(S); \
|
||
BK = bin_at(A, IDX); \
|
||
FD = BK->fd; \
|
||
if (FD == BK) mark_binblock(A, IDX); \
|
||
else \
|
||
{ \
|
||
while (FD != BK && S < chunksize(FD)) FD = FD->fd; \
|
||
BK = FD->bk; \
|
||
} \
|
||
P->bk = BK; \
|
||
P->fd = FD; \
|
||
FD->bk = BK->fd = P; \
|
||
} \
|
||
}
|
||
|
||
|
||
/* take a chunk off a list */
|
||
|
||
#define unlink(P, BK, FD) \
|
||
{ \
|
||
BK = P->bk; \
|
||
FD = P->fd; \
|
||
FD->bk = BK; \
|
||
BK->fd = FD; \
|
||
} \
|
||
|
||
/* Place p as the last remainder */
|
||
|
||
#define link_last_remainder(A, P) \
|
||
{ \
|
||
last_remainder(A)->fd = last_remainder(A)->bk = P; \
|
||
P->fd = P->bk = last_remainder(A); \
|
||
}
|
||
|
||
/* Clear the last_remainder bin */
|
||
|
||
#define clear_last_remainder(A) \
|
||
(last_remainder(A)->fd = last_remainder(A)->bk = last_remainder(A))
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
Extend the top-most chunk by obtaining memory from system.
|
||
Main interface to sbrk (but see also malloc_trim).
|
||
*/
|
||
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
/* This function is called only from one place, inline it. */
|
||
inline
|
||
#endif
|
||
static void
|
||
internal_function
|
||
#if __STD_C
|
||
malloc_extend_top(arena *ar_ptr, INTERNAL_SIZE_T nb)
|
||
#else
|
||
malloc_extend_top(ar_ptr, nb) arena *ar_ptr; INTERNAL_SIZE_T nb;
|
||
#endif
|
||
{
|
||
unsigned long pagesz = malloc_getpagesize;
|
||
mchunkptr old_top = top(ar_ptr); /* Record state of old top */
|
||
INTERNAL_SIZE_T old_top_size = chunksize(old_top);
|
||
INTERNAL_SIZE_T top_size; /* new size of top chunk */
|
||
|
||
#ifndef NO_THREADS
|
||
if(ar_ptr == &main_arena) {
|
||
#endif
|
||
|
||
char* brk; /* return value from sbrk */
|
||
INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */
|
||
INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */
|
||
char* new_brk; /* return of 2nd sbrk call */
|
||
char* old_end = (char*)(chunk_at_offset(old_top, old_top_size));
|
||
|
||
/* Pad request with top_pad plus minimal overhead */
|
||
INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE;
|
||
|
||
/* If not the first time through, round to preserve page boundary */
|
||
/* Otherwise, we need to correct to a page size below anyway. */
|
||
/* (We also correct below if an intervening foreign sbrk call.) */
|
||
|
||
if (sbrk_base != (char*)(-1))
|
||
sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1);
|
||
|
||
brk = (char*)(MORECORE (sbrk_size));
|
||
|
||
/* Fail if sbrk failed or if a foreign sbrk call killed our space */
|
||
if (brk == (char*)(MORECORE_FAILURE) ||
|
||
(brk < old_end && old_top != initial_top(&main_arena)))
|
||
return;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
/* Call the `morecore' hook if necessary. */
|
||
if (__after_morecore_hook)
|
||
(*__after_morecore_hook) ();
|
||
#endif
|
||
|
||
sbrked_mem += sbrk_size;
|
||
|
||
if (brk == old_end) { /* can just add bytes to current top */
|
||
top_size = sbrk_size + old_top_size;
|
||
set_head(old_top, top_size | PREV_INUSE);
|
||
old_top = 0; /* don't free below */
|
||
} else {
|
||
if (sbrk_base == (char*)(-1)) /* First time through. Record base */
|
||
sbrk_base = brk;
|
||
else
|
||
/* Someone else called sbrk(). Count those bytes as sbrked_mem. */
|
||
sbrked_mem += brk - (char*)old_end;
|
||
|
||
/* Guarantee alignment of first new chunk made from this space */
|
||
front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK;
|
||
if (front_misalign > 0) {
|
||
correction = (MALLOC_ALIGNMENT) - front_misalign;
|
||
brk += correction;
|
||
} else
|
||
correction = 0;
|
||
|
||
/* Guarantee the next brk will be at a page boundary */
|
||
correction += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1));
|
||
|
||
/* Allocate correction */
|
||
new_brk = (char*)(MORECORE (correction));
|
||
if (new_brk == (char*)(MORECORE_FAILURE)) return;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
/* Call the `morecore' hook if necessary. */
|
||
if (__after_morecore_hook)
|
||
(*__after_morecore_hook) ();
|
||
#endif
|
||
|
||
sbrked_mem += correction;
|
||
|
||
top(&main_arena) = (mchunkptr)brk;
|
||
top_size = new_brk - brk + correction;
|
||
set_head(top(&main_arena), top_size | PREV_INUSE);
|
||
|
||
if (old_top == initial_top(&main_arena))
|
||
old_top = 0; /* don't free below */
|
||
}
|
||
|
||
if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem)
|
||
max_sbrked_mem = sbrked_mem;
|
||
#ifdef NO_THREADS
|
||
if ((unsigned long)(mmapped_mem + sbrked_mem) >
|
||
(unsigned long)max_total_mem)
|
||
max_total_mem = mmapped_mem + sbrked_mem;
|
||
#endif
|
||
|
||
#ifndef NO_THREADS
|
||
} else { /* ar_ptr != &main_arena */
|
||
heap_info *old_heap, *heap;
|
||
size_t old_heap_size;
|
||
|
||
if(old_top_size < MINSIZE) /* this should never happen */
|
||
return;
|
||
|
||
/* First try to extend the current heap. */
|
||
if(MINSIZE + nb <= old_top_size)
|
||
return;
|
||
old_heap = heap_for_ptr(old_top);
|
||
old_heap_size = old_heap->size;
|
||
if(grow_heap(old_heap, MINSIZE + nb - old_top_size) == 0) {
|
||
ar_ptr->size += old_heap->size - old_heap_size;
|
||
top_size = ((char *)old_heap + old_heap->size) - (char *)old_top;
|
||
set_head(old_top, top_size | PREV_INUSE);
|
||
return;
|
||
}
|
||
|
||
/* A new heap must be created. */
|
||
heap = new_heap(nb + (MINSIZE + sizeof(*heap)));
|
||
if(!heap)
|
||
return;
|
||
heap->ar_ptr = ar_ptr;
|
||
heap->prev = old_heap;
|
||
ar_ptr->size += heap->size;
|
||
|
||
/* Set up the new top, so we can safely use chunk_free() below. */
|
||
top(ar_ptr) = chunk_at_offset(heap, sizeof(*heap));
|
||
top_size = heap->size - sizeof(*heap);
|
||
set_head(top(ar_ptr), top_size | PREV_INUSE);
|
||
}
|
||
#endif /* !defined(NO_THREADS) */
|
||
|
||
/* We always land on a page boundary */
|
||
assert(((unsigned long)((char*)top(ar_ptr) + top_size) & (pagesz-1)) == 0);
|
||
|
||
/* Setup fencepost and free the old top chunk. */
|
||
if(old_top) {
|
||
/* The fencepost takes at least MINSIZE bytes, because it might
|
||
become the top chunk again later. Note that a footer is set
|
||
up, too, although the chunk is marked in use. */
|
||
old_top_size -= MINSIZE;
|
||
set_head(chunk_at_offset(old_top, old_top_size + 2*SIZE_SZ), 0|PREV_INUSE);
|
||
if(old_top_size >= MINSIZE) {
|
||
set_head(chunk_at_offset(old_top, old_top_size), (2*SIZE_SZ)|PREV_INUSE);
|
||
set_foot(chunk_at_offset(old_top, old_top_size), (2*SIZE_SZ));
|
||
set_head_size(old_top, old_top_size);
|
||
chunk_free(ar_ptr, old_top);
|
||
} else {
|
||
set_head(old_top, (old_top_size + 2*SIZE_SZ)|PREV_INUSE);
|
||
set_foot(old_top, (old_top_size + 2*SIZE_SZ));
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
/* Main public routines */
|
||
|
||
|
||
/*
|
||
Malloc Algorithm:
|
||
|
||
The requested size is first converted into a usable form, `nb'.
|
||
This currently means to add 4 bytes overhead plus possibly more to
|
||
obtain 8-byte alignment and/or to obtain a size of at least
|
||
MINSIZE (currently 16, 24, or 32 bytes), the smallest allocatable
|
||
size. (All fits are considered `exact' if they are within MINSIZE
|
||
bytes.)
|
||
|
||
From there, the first successful of the following steps is taken:
|
||
|
||
1. The bin corresponding to the request size is scanned, and if
|
||
a chunk of exactly the right size is found, it is taken.
|
||
|
||
2. The most recently remaindered chunk is used if it is big
|
||
enough. This is a form of (roving) first fit, used only in
|
||
the absence of exact fits. Runs of consecutive requests use
|
||
the remainder of the chunk used for the previous such request
|
||
whenever possible. This limited use of a first-fit style
|
||
allocation strategy tends to give contiguous chunks
|
||
coextensive lifetimes, which improves locality and can reduce
|
||
fragmentation in the long run.
|
||
|
||
3. Other bins are scanned in increasing size order, using a
|
||
chunk big enough to fulfill the request, and splitting off
|
||
any remainder. This search is strictly by best-fit; i.e.,
|
||
the smallest (with ties going to approximately the least
|
||
recently used) chunk that fits is selected.
|
||
|
||
4. If large enough, the chunk bordering the end of memory
|
||
(`top') is split off. (This use of `top' is in accord with
|
||
the best-fit search rule. In effect, `top' is treated as
|
||
larger (and thus less well fitting) than any other available
|
||
chunk since it can be extended to be as large as necessary
|
||
(up to system limitations).
|
||
|
||
5. If the request size meets the mmap threshold and the
|
||
system supports mmap, and there are few enough currently
|
||
allocated mmapped regions, and a call to mmap succeeds,
|
||
the request is allocated via direct memory mapping.
|
||
|
||
6. Otherwise, the top of memory is extended by
|
||
obtaining more space from the system (normally using sbrk,
|
||
but definable to anything else via the MORECORE macro).
|
||
Memory is gathered from the system (in system page-sized
|
||
units) in a way that allows chunks obtained across different
|
||
sbrk calls to be consolidated, but does not require
|
||
contiguous memory. Thus, it should be safe to intersperse
|
||
mallocs with other sbrk calls.
|
||
|
||
|
||
All allocations are made from the `lowest' part of any found
|
||
chunk. (The implementation invariant is that prev_inuse is
|
||
always true of any allocated chunk; i.e., that each allocated
|
||
chunk borders either a previously allocated and still in-use chunk,
|
||
or the base of its memory arena.)
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* mALLOc(size_t bytes)
|
||
#else
|
||
Void_t* mALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
arena *ar_ptr;
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
mchunkptr victim;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
if (__malloc_hook != NULL) {
|
||
Void_t* result;
|
||
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
result = (*__malloc_hook)(bytes, __builtin_return_address (0));
|
||
#else
|
||
result = (*__malloc_hook)(bytes, NULL);
|
||
#endif
|
||
return result;
|
||
}
|
||
#endif
|
||
|
||
nb = request2size(bytes);
|
||
arena_get(ar_ptr, nb);
|
||
if(!ar_ptr)
|
||
return 0;
|
||
victim = chunk_alloc(ar_ptr, nb);
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
if(!victim) {
|
||
/* Maybe the failure is due to running out of mmapped areas. */
|
||
if(ar_ptr != &main_arena) {
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
victim = chunk_alloc(&main_arena, nb);
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
}
|
||
if(!victim) return 0;
|
||
}
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
static mchunkptr
|
||
internal_function
|
||
#if __STD_C
|
||
chunk_alloc(arena *ar_ptr, INTERNAL_SIZE_T nb)
|
||
#else
|
||
chunk_alloc(ar_ptr, nb) arena *ar_ptr; INTERNAL_SIZE_T nb;
|
||
#endif
|
||
{
|
||
mchunkptr victim; /* inspected/selected chunk */
|
||
INTERNAL_SIZE_T victim_size; /* its size */
|
||
int idx; /* index for bin traversal */
|
||
mbinptr bin; /* associated bin */
|
||
mchunkptr remainder; /* remainder from a split */
|
||
long remainder_size; /* its size */
|
||
int remainder_index; /* its bin index */
|
||
unsigned long block; /* block traverser bit */
|
||
int startidx; /* first bin of a traversed block */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mbinptr q; /* misc temp */
|
||
|
||
|
||
/* Check for exact match in a bin */
|
||
|
||
if (is_small_request(nb)) /* Faster version for small requests */
|
||
{
|
||
idx = smallbin_index(nb);
|
||
|
||
/* No traversal or size check necessary for small bins. */
|
||
|
||
q = bin_at(ar_ptr, idx);
|
||
victim = last(q);
|
||
|
||
/* Also scan the next one, since it would have a remainder < MINSIZE */
|
||
if (victim == q)
|
||
{
|
||
q = next_bin(q);
|
||
victim = last(q);
|
||
}
|
||
if (victim != q)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
unlink(victim, bck, fwd);
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
}
|
||
|
||
idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */
|
||
|
||
}
|
||
else
|
||
{
|
||
idx = bin_index(nb);
|
||
bin = bin_at(ar_ptr, idx);
|
||
|
||
for (victim = last(bin); victim != bin; victim = victim->bk)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
remainder_size = victim_size - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) /* too big */
|
||
{
|
||
--idx; /* adjust to rescan below after checking last remainder */
|
||
break;
|
||
}
|
||
|
||
else if (remainder_size >= 0) /* exact fit */
|
||
{
|
||
unlink(victim, bck, fwd);
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
}
|
||
}
|
||
|
||
++idx;
|
||
|
||
}
|
||
|
||
/* Try to use the last split-off remainder */
|
||
|
||
if ( (victim = last_remainder(ar_ptr)->fd) != last_remainder(ar_ptr))
|
||
{
|
||
victim_size = chunksize(victim);
|
||
remainder_size = victim_size - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) /* re-split */
|
||
{
|
||
remainder = chunk_at_offset(victim, nb);
|
||
set_head(victim, nb | PREV_INUSE);
|
||
link_last_remainder(ar_ptr, remainder);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
}
|
||
|
||
clear_last_remainder(ar_ptr);
|
||
|
||
if (remainder_size >= 0) /* exhaust */
|
||
{
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
}
|
||
|
||
/* Else place in bin */
|
||
|
||
frontlink(ar_ptr, victim, victim_size, remainder_index, bck, fwd);
|
||
}
|
||
|
||
/*
|
||
If there are any possibly nonempty big-enough blocks,
|
||
search for best fitting chunk by scanning bins in blockwidth units.
|
||
*/
|
||
|
||
if ( (block = idx2binblock(idx)) <= binblocks(ar_ptr))
|
||
{
|
||
|
||
/* Get to the first marked block */
|
||
|
||
if ( (block & binblocks(ar_ptr)) == 0)
|
||
{
|
||
/* force to an even block boundary */
|
||
idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH;
|
||
block <<= 1;
|
||
while ((block & binblocks(ar_ptr)) == 0)
|
||
{
|
||
idx += BINBLOCKWIDTH;
|
||
block <<= 1;
|
||
}
|
||
}
|
||
|
||
/* For each possibly nonempty block ... */
|
||
for (;;)
|
||
{
|
||
startidx = idx; /* (track incomplete blocks) */
|
||
q = bin = bin_at(ar_ptr, idx);
|
||
|
||
/* For each bin in this block ... */
|
||
do
|
||
{
|
||
/* Find and use first big enough chunk ... */
|
||
|
||
for (victim = last(bin); victim != bin; victim = victim->bk)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
remainder_size = victim_size - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) /* split */
|
||
{
|
||
remainder = chunk_at_offset(victim, nb);
|
||
set_head(victim, nb | PREV_INUSE);
|
||
unlink(victim, bck, fwd);
|
||
link_last_remainder(ar_ptr, remainder);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
}
|
||
|
||
else if (remainder_size >= 0) /* take */
|
||
{
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
unlink(victim, bck, fwd);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
}
|
||
|
||
}
|
||
|
||
bin = next_bin(bin);
|
||
|
||
} while ((++idx & (BINBLOCKWIDTH - 1)) != 0);
|
||
|
||
/* Clear out the block bit. */
|
||
|
||
do /* Possibly backtrack to try to clear a partial block */
|
||
{
|
||
if ((startidx & (BINBLOCKWIDTH - 1)) == 0)
|
||
{
|
||
binblocks(ar_ptr) &= ~block;
|
||
break;
|
||
}
|
||
--startidx;
|
||
q = prev_bin(q);
|
||
} while (first(q) == q);
|
||
|
||
/* Get to the next possibly nonempty block */
|
||
|
||
if ( (block <<= 1) <= binblocks(ar_ptr) && (block != 0) )
|
||
{
|
||
while ((block & binblocks(ar_ptr)) == 0)
|
||
{
|
||
idx += BINBLOCKWIDTH;
|
||
block <<= 1;
|
||
}
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
|
||
|
||
/* Try to use top chunk */
|
||
|
||
/* Require that there be a remainder, ensuring top always exists */
|
||
if ( (remainder_size = chunksize(top(ar_ptr)) - nb) < (long)MINSIZE)
|
||
{
|
||
|
||
#if HAVE_MMAP
|
||
/* If big and would otherwise need to extend, try to use mmap instead */
|
||
if ((unsigned long)nb >= (unsigned long)mmap_threshold &&
|
||
(victim = mmap_chunk(nb)) != 0)
|
||
return victim;
|
||
#endif
|
||
|
||
/* Try to extend */
|
||
malloc_extend_top(ar_ptr, nb);
|
||
if ((remainder_size = chunksize(top(ar_ptr)) - nb) < (long)MINSIZE)
|
||
return 0; /* propagate failure */
|
||
}
|
||
|
||
victim = top(ar_ptr);
|
||
set_head(victim, nb | PREV_INUSE);
|
||
top(ar_ptr) = chunk_at_offset(victim, nb);
|
||
set_head(top(ar_ptr), remainder_size | PREV_INUSE);
|
||
check_malloced_chunk(ar_ptr, victim, nb);
|
||
return victim;
|
||
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
|
||
free() algorithm :
|
||
|
||
cases:
|
||
|
||
1. free(0) has no effect.
|
||
|
||
2. If the chunk was allocated via mmap, it is released via munmap().
|
||
|
||
3. If a returned chunk borders the current high end of memory,
|
||
it is consolidated into the top, and if the total unused
|
||
topmost memory exceeds the trim threshold, malloc_trim is
|
||
called.
|
||
|
||
4. Other chunks are consolidated as they arrive, and
|
||
placed in corresponding bins. (This includes the case of
|
||
consolidating with the current `last_remainder').
|
||
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
void fREe(Void_t* mem)
|
||
#else
|
||
void fREe(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
arena *ar_ptr;
|
||
mchunkptr p; /* chunk corresponding to mem */
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
if (__free_hook != NULL) {
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
(*__free_hook)(mem, __builtin_return_address (0));
|
||
#else
|
||
(*__free_hook)(mem, NULL);
|
||
#endif
|
||
return;
|
||
}
|
||
#endif
|
||
|
||
if (mem == 0) /* free(0) has no effect */
|
||
return;
|
||
|
||
p = mem2chunk(mem);
|
||
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(p)) /* release mmapped memory. */
|
||
{
|
||
munmap_chunk(p);
|
||
return;
|
||
}
|
||
#endif
|
||
|
||
ar_ptr = arena_for_ptr(p);
|
||
#if THREAD_STATS
|
||
if(!mutex_trylock(&ar_ptr->mutex))
|
||
++(ar_ptr->stat_lock_direct);
|
||
else {
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
++(ar_ptr->stat_lock_wait);
|
||
}
|
||
#else
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
#endif
|
||
chunk_free(ar_ptr, p);
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
}
|
||
|
||
static void
|
||
internal_function
|
||
#if __STD_C
|
||
chunk_free(arena *ar_ptr, mchunkptr p)
|
||
#else
|
||
chunk_free(ar_ptr, p) arena *ar_ptr; mchunkptr p;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T hd = p->size; /* its head field */
|
||
INTERNAL_SIZE_T sz; /* its size */
|
||
int idx; /* its bin index */
|
||
mchunkptr next; /* next contiguous chunk */
|
||
INTERNAL_SIZE_T nextsz; /* its size */
|
||
INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
int islr; /* track whether merging with last_remainder */
|
||
|
||
check_inuse_chunk(ar_ptr, p);
|
||
|
||
sz = hd & ~PREV_INUSE;
|
||
next = chunk_at_offset(p, sz);
|
||
nextsz = chunksize(next);
|
||
|
||
if (next == top(ar_ptr)) /* merge with top */
|
||
{
|
||
sz += nextsz;
|
||
|
||
if (!(hd & PREV_INUSE)) /* consolidate backward */
|
||
{
|
||
prevsz = p->prev_size;
|
||
p = chunk_at_offset(p, -prevsz);
|
||
sz += prevsz;
|
||
unlink(p, bck, fwd);
|
||
}
|
||
|
||
set_head(p, sz | PREV_INUSE);
|
||
top(ar_ptr) = p;
|
||
|
||
#ifndef NO_THREADS
|
||
if(ar_ptr == &main_arena) {
|
||
#endif
|
||
if ((unsigned long)(sz) >= (unsigned long)trim_threshold)
|
||
main_trim(top_pad);
|
||
#ifndef NO_THREADS
|
||
} else {
|
||
heap_info *heap = heap_for_ptr(p);
|
||
|
||
assert(heap->ar_ptr == ar_ptr);
|
||
|
||
/* Try to get rid of completely empty heaps, if possible. */
|
||
if((unsigned long)(sz) >= (unsigned long)trim_threshold ||
|
||
p == chunk_at_offset(heap, sizeof(*heap)))
|
||
heap_trim(heap, top_pad);
|
||
}
|
||
#endif
|
||
return;
|
||
}
|
||
|
||
islr = 0;
|
||
|
||
if (!(hd & PREV_INUSE)) /* consolidate backward */
|
||
{
|
||
prevsz = p->prev_size;
|
||
p = chunk_at_offset(p, -prevsz);
|
||
sz += prevsz;
|
||
|
||
if (p->fd == last_remainder(ar_ptr)) /* keep as last_remainder */
|
||
islr = 1;
|
||
else
|
||
unlink(p, bck, fwd);
|
||
}
|
||
|
||
if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */
|
||
{
|
||
sz += nextsz;
|
||
|
||
if (!islr && next->fd == last_remainder(ar_ptr))
|
||
/* re-insert last_remainder */
|
||
{
|
||
islr = 1;
|
||
link_last_remainder(ar_ptr, p);
|
||
}
|
||
else
|
||
unlink(next, bck, fwd);
|
||
|
||
next = chunk_at_offset(p, sz);
|
||
}
|
||
else
|
||
set_head(next, nextsz); /* clear inuse bit */
|
||
|
||
set_head(p, sz | PREV_INUSE);
|
||
next->prev_size = sz;
|
||
if (!islr)
|
||
frontlink(ar_ptr, p, sz, idx, bck, fwd);
|
||
|
||
#ifndef NO_THREADS
|
||
/* Check whether the heap containing top can go away now. */
|
||
if(next->size < MINSIZE &&
|
||
(unsigned long)sz > trim_threshold &&
|
||
ar_ptr != &main_arena) { /* fencepost */
|
||
heap_info* heap = heap_for_ptr(top(ar_ptr));
|
||
|
||
if(top(ar_ptr) == chunk_at_offset(heap, sizeof(*heap)) &&
|
||
heap->prev == heap_for_ptr(p))
|
||
heap_trim(heap, top_pad);
|
||
}
|
||
#endif
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
|
||
Realloc algorithm:
|
||
|
||
Chunks that were obtained via mmap cannot be extended or shrunk
|
||
unless HAVE_MREMAP is defined, in which case mremap is used.
|
||
Otherwise, if their reallocation is for additional space, they are
|
||
copied. If for less, they are just left alone.
|
||
|
||
Otherwise, if the reallocation is for additional space, and the
|
||
chunk can be extended, it is, else a malloc-copy-free sequence is
|
||
taken. There are several different ways that a chunk could be
|
||
extended. All are tried:
|
||
|
||
* Extending forward into following adjacent free chunk.
|
||
* Shifting backwards, joining preceding adjacent space
|
||
* Both shifting backwards and extending forward.
|
||
* Extending into newly sbrked space
|
||
|
||
Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a
|
||
size argument of zero (re)allocates a minimum-sized chunk.
|
||
|
||
If the reallocation is for less space, and the new request is for
|
||
a `small' (<512 bytes) size, then the newly unused space is lopped
|
||
off and freed.
|
||
|
||
The old unix realloc convention of allowing the last-free'd chunk
|
||
to be used as an argument to realloc is no longer supported.
|
||
I don't know of any programs still relying on this feature,
|
||
and allowing it would also allow too many other incorrect
|
||
usages of realloc to be sensible.
|
||
|
||
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* rEALLOc(Void_t* oldmem, size_t bytes)
|
||
#else
|
||
Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
|
||
#endif
|
||
{
|
||
arena *ar_ptr;
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
|
||
mchunkptr oldp; /* chunk corresponding to oldmem */
|
||
INTERNAL_SIZE_T oldsize; /* its size */
|
||
|
||
mchunkptr newp; /* chunk to return */
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
if (__realloc_hook != NULL) {
|
||
Void_t* result;
|
||
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
result = (*__realloc_hook)(oldmem, bytes, __builtin_return_address (0));
|
||
#else
|
||
result = (*__realloc_hook)(oldmem, bytes, NULL);
|
||
#endif
|
||
return result;
|
||
}
|
||
#endif
|
||
|
||
#ifdef REALLOC_ZERO_BYTES_FREES
|
||
if (bytes == 0 && oldmem != NULL) { fREe(oldmem); return 0; }
|
||
#endif
|
||
|
||
/* realloc of null is supposed to be same as malloc */
|
||
if (oldmem == 0) return mALLOc(bytes);
|
||
|
||
oldp = mem2chunk(oldmem);
|
||
oldsize = chunksize(oldp);
|
||
|
||
nb = request2size(bytes);
|
||
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(oldp))
|
||
{
|
||
Void_t* newmem;
|
||
|
||
#if HAVE_MREMAP
|
||
newp = mremap_chunk(oldp, nb);
|
||
if(newp) return chunk2mem(newp);
|
||
#endif
|
||
/* Note the extra SIZE_SZ overhead. */
|
||
if(oldsize - SIZE_SZ >= nb) return oldmem; /* do nothing */
|
||
/* Must alloc, copy, free. */
|
||
newmem = mALLOc(bytes);
|
||
if (newmem == 0) return 0; /* propagate failure */
|
||
MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ);
|
||
munmap_chunk(oldp);
|
||
return newmem;
|
||
}
|
||
#endif
|
||
|
||
ar_ptr = arena_for_ptr(oldp);
|
||
#if THREAD_STATS
|
||
if(!mutex_trylock(&ar_ptr->mutex))
|
||
++(ar_ptr->stat_lock_direct);
|
||
else {
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
++(ar_ptr->stat_lock_wait);
|
||
}
|
||
#else
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
#endif
|
||
|
||
#ifndef NO_THREADS
|
||
/* As in malloc(), remember this arena for the next allocation. */
|
||
tsd_setspecific(arena_key, (Void_t *)ar_ptr);
|
||
#endif
|
||
|
||
newp = chunk_realloc(ar_ptr, oldp, oldsize, nb);
|
||
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
return newp ? chunk2mem(newp) : NULL;
|
||
}
|
||
|
||
static mchunkptr
|
||
internal_function
|
||
#if __STD_C
|
||
chunk_realloc(arena* ar_ptr, mchunkptr oldp, INTERNAL_SIZE_T oldsize,
|
||
INTERNAL_SIZE_T nb)
|
||
#else
|
||
chunk_realloc(ar_ptr, oldp, oldsize, nb)
|
||
arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb;
|
||
#endif
|
||
{
|
||
mchunkptr newp = oldp; /* chunk to return */
|
||
INTERNAL_SIZE_T newsize = oldsize; /* its size */
|
||
|
||
mchunkptr next; /* next contiguous chunk after oldp */
|
||
INTERNAL_SIZE_T nextsize; /* its size */
|
||
|
||
mchunkptr prev; /* previous contiguous chunk before oldp */
|
||
INTERNAL_SIZE_T prevsize; /* its size */
|
||
|
||
mchunkptr remainder; /* holds split off extra space from newp */
|
||
INTERNAL_SIZE_T remainder_size; /* its size */
|
||
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
|
||
check_inuse_chunk(ar_ptr, oldp);
|
||
|
||
if ((long)(oldsize) < (long)(nb))
|
||
{
|
||
|
||
/* Try expanding forward */
|
||
|
||
next = chunk_at_offset(oldp, oldsize);
|
||
if (next == top(ar_ptr) || !inuse(next))
|
||
{
|
||
nextsize = chunksize(next);
|
||
|
||
/* Forward into top only if a remainder */
|
||
if (next == top(ar_ptr))
|
||
{
|
||
if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE))
|
||
{
|
||
newsize += nextsize;
|
||
top(ar_ptr) = chunk_at_offset(oldp, nb);
|
||
set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE);
|
||
set_head_size(oldp, nb);
|
||
return oldp;
|
||
}
|
||
}
|
||
|
||
/* Forward into next chunk */
|
||
else if (((long)(nextsize + newsize) >= (long)(nb)))
|
||
{
|
||
unlink(next, bck, fwd);
|
||
newsize += nextsize;
|
||
goto split;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
next = 0;
|
||
nextsize = 0;
|
||
}
|
||
|
||
/* Try shifting backwards. */
|
||
|
||
if (!prev_inuse(oldp))
|
||
{
|
||
prev = prev_chunk(oldp);
|
||
prevsize = chunksize(prev);
|
||
|
||
/* try forward + backward first to save a later consolidation */
|
||
|
||
if (next != 0)
|
||
{
|
||
/* into top */
|
||
if (next == top(ar_ptr))
|
||
{
|
||
if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE))
|
||
{
|
||
unlink(prev, bck, fwd);
|
||
newp = prev;
|
||
newsize += prevsize + nextsize;
|
||
MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ);
|
||
top(ar_ptr) = chunk_at_offset(newp, nb);
|
||
set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE);
|
||
set_head_size(newp, nb);
|
||
return newp;
|
||
}
|
||
}
|
||
|
||
/* into next chunk */
|
||
else if (((long)(nextsize + prevsize + newsize) >= (long)(nb)))
|
||
{
|
||
unlink(next, bck, fwd);
|
||
unlink(prev, bck, fwd);
|
||
newp = prev;
|
||
newsize += nextsize + prevsize;
|
||
MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ);
|
||
goto split;
|
||
}
|
||
}
|
||
|
||
/* backward only */
|
||
if (prev != 0 && (long)(prevsize + newsize) >= (long)nb)
|
||
{
|
||
unlink(prev, bck, fwd);
|
||
newp = prev;
|
||
newsize += prevsize;
|
||
MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ);
|
||
goto split;
|
||
}
|
||
}
|
||
|
||
/* Must allocate */
|
||
|
||
newp = chunk_alloc (ar_ptr, nb);
|
||
|
||
if (newp == 0) {
|
||
/* Maybe the failure is due to running out of mmapped areas. */
|
||
if (ar_ptr != &main_arena) {
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
newp = chunk_alloc(&main_arena, nb);
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
}
|
||
if (newp == 0) /* propagate failure */
|
||
return 0;
|
||
}
|
||
|
||
/* Avoid copy if newp is next chunk after oldp. */
|
||
/* (This can only happen when new chunk is sbrk'ed.) */
|
||
|
||
if ( newp == next_chunk(oldp))
|
||
{
|
||
newsize += chunksize(newp);
|
||
newp = oldp;
|
||
goto split;
|
||
}
|
||
|
||
/* Otherwise copy, free, and exit */
|
||
MALLOC_COPY(chunk2mem(newp), chunk2mem(oldp), oldsize - SIZE_SZ);
|
||
chunk_free(ar_ptr, oldp);
|
||
return newp;
|
||
}
|
||
|
||
|
||
split: /* split off extra room in old or expanded chunk */
|
||
|
||
if (newsize - nb >= MINSIZE) /* split off remainder */
|
||
{
|
||
remainder = chunk_at_offset(newp, nb);
|
||
remainder_size = newsize - nb;
|
||
set_head_size(newp, nb);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_inuse_bit_at_offset(remainder, remainder_size);
|
||
chunk_free(ar_ptr, remainder);
|
||
}
|
||
else
|
||
{
|
||
set_head_size(newp, newsize);
|
||
set_inuse_bit_at_offset(newp, newsize);
|
||
}
|
||
|
||
check_inuse_chunk(ar_ptr, newp);
|
||
return newp;
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
|
||
memalign algorithm:
|
||
|
||
memalign requests more than enough space from malloc, finds a spot
|
||
within that chunk that meets the alignment request, and then
|
||
possibly frees the leading and trailing space.
|
||
|
||
The alignment argument must be a power of two. This property is not
|
||
checked by memalign, so misuse may result in random runtime errors.
|
||
|
||
8-byte alignment is guaranteed by normal malloc calls, so don't
|
||
bother calling memalign with an argument of 8 or less.
|
||
|
||
Overreliance on memalign is a sure way to fragment space.
|
||
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* mEMALIGn(size_t alignment, size_t bytes)
|
||
#else
|
||
Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
|
||
#endif
|
||
{
|
||
arena *ar_ptr;
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
mchunkptr p;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
if (__memalign_hook != NULL) {
|
||
Void_t* result;
|
||
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
result = (*__memalign_hook)(alignment, bytes,
|
||
__builtin_return_address (0));
|
||
#else
|
||
result = (*__memalign_hook)(alignment, bytes, NULL);
|
||
#endif
|
||
return result;
|
||
}
|
||
#endif
|
||
|
||
/* If need less alignment than we give anyway, just relay to malloc */
|
||
|
||
if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes);
|
||
|
||
/* Otherwise, ensure that it is at least a minimum chunk size */
|
||
|
||
if (alignment < MINSIZE) alignment = MINSIZE;
|
||
|
||
nb = request2size(bytes);
|
||
arena_get(ar_ptr, nb + alignment + MINSIZE);
|
||
if(!ar_ptr)
|
||
return 0;
|
||
p = chunk_align(ar_ptr, nb, alignment);
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
if(!p) {
|
||
/* Maybe the failure is due to running out of mmapped areas. */
|
||
if(ar_ptr != &main_arena) {
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
p = chunk_align(&main_arena, nb, alignment);
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
}
|
||
if(!p) return 0;
|
||
}
|
||
return chunk2mem(p);
|
||
}
|
||
|
||
static mchunkptr
|
||
internal_function
|
||
#if __STD_C
|
||
chunk_align(arena* ar_ptr, INTERNAL_SIZE_T nb, size_t alignment)
|
||
#else
|
||
chunk_align(ar_ptr, nb, alignment)
|
||
arena* ar_ptr; INTERNAL_SIZE_T nb; size_t alignment;
|
||
#endif
|
||
{
|
||
char* m; /* memory returned by malloc call */
|
||
mchunkptr p; /* corresponding chunk */
|
||
char* brk; /* alignment point within p */
|
||
mchunkptr newp; /* chunk to return */
|
||
INTERNAL_SIZE_T newsize; /* its size */
|
||
INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */
|
||
mchunkptr remainder; /* spare room at end to split off */
|
||
long remainder_size; /* its size */
|
||
|
||
/* Call chunk_alloc with worst case padding to hit alignment. */
|
||
p = chunk_alloc(ar_ptr, nb + alignment + MINSIZE);
|
||
if (p == 0)
|
||
return 0; /* propagate failure */
|
||
|
||
m = chunk2mem(p);
|
||
|
||
if ((((unsigned long)(m)) % alignment) == 0) /* aligned */
|
||
{
|
||
#if HAVE_MMAP
|
||
if(chunk_is_mmapped(p)) {
|
||
return p; /* nothing more to do */
|
||
}
|
||
#endif
|
||
}
|
||
else /* misaligned */
|
||
{
|
||
/*
|
||
Find an aligned spot inside chunk.
|
||
Since we need to give back leading space in a chunk of at
|
||
least MINSIZE, if the first calculation places us at
|
||
a spot with less than MINSIZE leader, we can move to the
|
||
next aligned spot -- we've allocated enough total room so that
|
||
this is always possible.
|
||
*/
|
||
|
||
brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -alignment);
|
||
if ((long)(brk - (char*)(p)) < (long)MINSIZE) brk += alignment;
|
||
|
||
newp = (mchunkptr)brk;
|
||
leadsize = brk - (char*)(p);
|
||
newsize = chunksize(p) - leadsize;
|
||
|
||
#if HAVE_MMAP
|
||
if(chunk_is_mmapped(p))
|
||
{
|
||
newp->prev_size = p->prev_size + leadsize;
|
||
set_head(newp, newsize|IS_MMAPPED);
|
||
return newp;
|
||
}
|
||
#endif
|
||
|
||
/* give back leader, use the rest */
|
||
|
||
set_head(newp, newsize | PREV_INUSE);
|
||
set_inuse_bit_at_offset(newp, newsize);
|
||
set_head_size(p, leadsize);
|
||
chunk_free(ar_ptr, p);
|
||
p = newp;
|
||
|
||
assert (newsize>=nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0);
|
||
}
|
||
|
||
/* Also give back spare room at the end */
|
||
|
||
remainder_size = chunksize(p) - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE)
|
||
{
|
||
remainder = chunk_at_offset(p, nb);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_head_size(p, nb);
|
||
chunk_free(ar_ptr, remainder);
|
||
}
|
||
|
||
check_inuse_chunk(ar_ptr, p);
|
||
return p;
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
valloc just invokes memalign with alignment argument equal
|
||
to the page size of the system (or as near to this as can
|
||
be figured out from all the includes/defines above.)
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* vALLOc(size_t bytes)
|
||
#else
|
||
Void_t* vALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
return mEMALIGn (malloc_getpagesize, bytes);
|
||
}
|
||
|
||
/*
|
||
pvalloc just invokes valloc for the nearest pagesize
|
||
that will accommodate request
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* pvALLOc(size_t bytes)
|
||
#else
|
||
Void_t* pvALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
size_t pagesize = malloc_getpagesize;
|
||
return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1));
|
||
}
|
||
|
||
/*
|
||
|
||
calloc calls chunk_alloc, then zeroes out the allocated chunk.
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* cALLOc(size_t n, size_t elem_size)
|
||
#else
|
||
Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size;
|
||
#endif
|
||
{
|
||
arena *ar_ptr;
|
||
mchunkptr p, oldtop;
|
||
INTERNAL_SIZE_T sz, csz, oldtopsize;
|
||
Void_t* mem;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
if (__malloc_hook != NULL) {
|
||
sz = n * elem_size;
|
||
#if defined __GNUC__ && __GNUC__ >= 2
|
||
mem = (*__malloc_hook)(sz, __builtin_return_address (0));
|
||
#else
|
||
mem = (*__malloc_hook)(sz, NULL);
|
||
#endif
|
||
if(mem == 0)
|
||
return 0;
|
||
#ifdef HAVE_MEMSET
|
||
return memset(mem, 0, sz);
|
||
#else
|
||
while(sz > 0) ((char*)mem)[--sz] = 0; /* rather inefficient */
|
||
return mem;
|
||
#endif
|
||
}
|
||
#endif
|
||
|
||
sz = request2size(n * elem_size);
|
||
arena_get(ar_ptr, sz);
|
||
if(!ar_ptr)
|
||
return 0;
|
||
|
||
/* check if expand_top called, in which case don't need to clear */
|
||
#if MORECORE_CLEARS
|
||
oldtop = top(ar_ptr);
|
||
oldtopsize = chunksize(top(ar_ptr));
|
||
#endif
|
||
p = chunk_alloc (ar_ptr, sz);
|
||
|
||
/* Only clearing follows, so we can unlock early. */
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
|
||
if (p == 0) {
|
||
/* Maybe the failure is due to running out of mmapped areas. */
|
||
if(ar_ptr != &main_arena) {
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
p = chunk_alloc(&main_arena, sz);
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
}
|
||
if (p == 0) return 0;
|
||
}
|
||
mem = chunk2mem(p);
|
||
|
||
/* Two optional cases in which clearing not necessary */
|
||
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(p)) return mem;
|
||
#endif
|
||
|
||
csz = chunksize(p);
|
||
|
||
#if MORECORE_CLEARS
|
||
if (p == oldtop && csz > oldtopsize) {
|
||
/* clear only the bytes from non-freshly-sbrked memory */
|
||
csz = oldtopsize;
|
||
}
|
||
#endif
|
||
|
||
MALLOC_ZERO(mem, csz - SIZE_SZ);
|
||
return mem;
|
||
}
|
||
|
||
/*
|
||
|
||
cfree just calls free. It is needed/defined on some systems
|
||
that pair it with calloc, presumably for odd historical reasons.
|
||
|
||
*/
|
||
|
||
#if !defined(_LIBC)
|
||
#if __STD_C
|
||
void cfree(Void_t *mem)
|
||
#else
|
||
void cfree(mem) Void_t *mem;
|
||
#endif
|
||
{
|
||
free(mem);
|
||
}
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
|
||
Malloc_trim gives memory back to the system (via negative
|
||
arguments to sbrk) if there is unused memory at the `high' end of
|
||
the malloc pool. You can call this after freeing large blocks of
|
||
memory to potentially reduce the system-level memory requirements
|
||
of a program. However, it cannot guarantee to reduce memory. Under
|
||
some allocation patterns, some large free blocks of memory will be
|
||
locked between two used chunks, so they cannot be given back to
|
||
the system.
|
||
|
||
The `pad' argument to malloc_trim represents the amount of free
|
||
trailing space to leave untrimmed. If this argument is zero,
|
||
only the minimum amount of memory to maintain internal data
|
||
structures will be left (one page or less). Non-zero arguments
|
||
can be supplied to maintain enough trailing space to service
|
||
future expected allocations without having to re-obtain memory
|
||
from the system.
|
||
|
||
Malloc_trim returns 1 if it actually released any memory, else 0.
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
int mALLOC_TRIm(size_t pad)
|
||
#else
|
||
int mALLOC_TRIm(pad) size_t pad;
|
||
#endif
|
||
{
|
||
int res;
|
||
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
res = main_trim(pad);
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
return res;
|
||
}
|
||
|
||
/* Trim the main arena. */
|
||
|
||
static int
|
||
internal_function
|
||
#if __STD_C
|
||
main_trim(size_t pad)
|
||
#else
|
||
main_trim(pad) size_t pad;
|
||
#endif
|
||
{
|
||
mchunkptr top_chunk; /* The current top chunk */
|
||
long top_size; /* Amount of top-most memory */
|
||
long extra; /* Amount to release */
|
||
char* current_brk; /* address returned by pre-check sbrk call */
|
||
char* new_brk; /* address returned by negative sbrk call */
|
||
|
||
unsigned long pagesz = malloc_getpagesize;
|
||
|
||
top_chunk = top(&main_arena);
|
||
top_size = chunksize(top_chunk);
|
||
extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz;
|
||
|
||
if (extra < (long)pagesz) /* Not enough memory to release */
|
||
return 0;
|
||
|
||
/* Test to make sure no one else called sbrk */
|
||
current_brk = (char*)(MORECORE (0));
|
||
if (current_brk != (char*)(top_chunk) + top_size)
|
||
return 0; /* Apparently we don't own memory; must fail */
|
||
|
||
new_brk = (char*)(MORECORE (-extra));
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
/* Call the `morecore' hook if necessary. */
|
||
if (__after_morecore_hook)
|
||
(*__after_morecore_hook) ();
|
||
#endif
|
||
|
||
if (new_brk == (char*)(MORECORE_FAILURE)) { /* sbrk failed? */
|
||
/* Try to figure out what we have */
|
||
current_brk = (char*)(MORECORE (0));
|
||
top_size = current_brk - (char*)top_chunk;
|
||
if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */
|
||
{
|
||
sbrked_mem = current_brk - sbrk_base;
|
||
set_head(top_chunk, top_size | PREV_INUSE);
|
||
}
|
||
check_chunk(&main_arena, top_chunk);
|
||
return 0;
|
||
}
|
||
sbrked_mem -= extra;
|
||
|
||
/* Success. Adjust top accordingly. */
|
||
set_head(top_chunk, (top_size - extra) | PREV_INUSE);
|
||
check_chunk(&main_arena, top_chunk);
|
||
return 1;
|
||
}
|
||
|
||
#ifndef NO_THREADS
|
||
|
||
static int
|
||
internal_function
|
||
#if __STD_C
|
||
heap_trim(heap_info *heap, size_t pad)
|
||
#else
|
||
heap_trim(heap, pad) heap_info *heap; size_t pad;
|
||
#endif
|
||
{
|
||
unsigned long pagesz = malloc_getpagesize;
|
||
arena *ar_ptr = heap->ar_ptr;
|
||
mchunkptr top_chunk = top(ar_ptr), p, bck, fwd;
|
||
heap_info *prev_heap;
|
||
long new_size, top_size, extra;
|
||
|
||
/* Can this heap go away completely ? */
|
||
while(top_chunk == chunk_at_offset(heap, sizeof(*heap))) {
|
||
prev_heap = heap->prev;
|
||
p = chunk_at_offset(prev_heap, prev_heap->size - (MINSIZE-2*SIZE_SZ));
|
||
assert(p->size == (0|PREV_INUSE)); /* must be fencepost */
|
||
p = prev_chunk(p);
|
||
new_size = chunksize(p) + (MINSIZE-2*SIZE_SZ);
|
||
assert(new_size>0 && new_size<(long)(2*MINSIZE));
|
||
if(!prev_inuse(p))
|
||
new_size += p->prev_size;
|
||
assert(new_size>0 && new_size<HEAP_MAX_SIZE);
|
||
if(new_size + (HEAP_MAX_SIZE - prev_heap->size) < pad + MINSIZE + pagesz)
|
||
break;
|
||
ar_ptr->size -= heap->size;
|
||
delete_heap(heap);
|
||
heap = prev_heap;
|
||
if(!prev_inuse(p)) { /* consolidate backward */
|
||
p = prev_chunk(p);
|
||
unlink(p, bck, fwd);
|
||
}
|
||
assert(((unsigned long)((char*)p + new_size) & (pagesz-1)) == 0);
|
||
assert( ((char*)p + new_size) == ((char*)heap + heap->size) );
|
||
top(ar_ptr) = top_chunk = p;
|
||
set_head(top_chunk, new_size | PREV_INUSE);
|
||
check_chunk(ar_ptr, top_chunk);
|
||
}
|
||
top_size = chunksize(top_chunk);
|
||
extra = ((top_size - pad - MINSIZE + (pagesz-1))/pagesz - 1) * pagesz;
|
||
if(extra < (long)pagesz)
|
||
return 0;
|
||
/* Try to shrink. */
|
||
if(grow_heap(heap, -extra) != 0)
|
||
return 0;
|
||
ar_ptr->size -= extra;
|
||
|
||
/* Success. Adjust top accordingly. */
|
||
set_head(top_chunk, (top_size - extra) | PREV_INUSE);
|
||
check_chunk(ar_ptr, top_chunk);
|
||
return 1;
|
||
}
|
||
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
malloc_usable_size:
|
||
|
||
This routine tells you how many bytes you can actually use in an
|
||
allocated chunk, which may be more than you requested (although
|
||
often not). You can use this many bytes without worrying about
|
||
overwriting other allocated objects. Not a particularly great
|
||
programming practice, but still sometimes useful.
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
size_t mALLOC_USABLE_SIZe(Void_t* mem)
|
||
#else
|
||
size_t mALLOC_USABLE_SIZe(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
|
||
if (mem == 0)
|
||
return 0;
|
||
else
|
||
{
|
||
p = mem2chunk(mem);
|
||
if(!chunk_is_mmapped(p))
|
||
{
|
||
if (!inuse(p)) return 0;
|
||
check_inuse_chunk(arena_for_ptr(mem), p);
|
||
return chunksize(p) - SIZE_SZ;
|
||
}
|
||
return chunksize(p) - 2*SIZE_SZ;
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
/* Utility to update mallinfo for malloc_stats() and mallinfo() */
|
||
|
||
static void
|
||
#if __STD_C
|
||
malloc_update_mallinfo(arena *ar_ptr, struct mallinfo *mi)
|
||
#else
|
||
malloc_update_mallinfo(ar_ptr, mi) arena *ar_ptr; struct mallinfo *mi;
|
||
#endif
|
||
{
|
||
int i, navail;
|
||
mbinptr b;
|
||
mchunkptr p;
|
||
#if MALLOC_DEBUG
|
||
mchunkptr q;
|
||
#endif
|
||
INTERNAL_SIZE_T avail;
|
||
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
avail = chunksize(top(ar_ptr));
|
||
navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0;
|
||
|
||
for (i = 1; i < NAV; ++i)
|
||
{
|
||
b = bin_at(ar_ptr, i);
|
||
for (p = last(b); p != b; p = p->bk)
|
||
{
|
||
#if MALLOC_DEBUG
|
||
check_free_chunk(ar_ptr, p);
|
||
for (q = next_chunk(p);
|
||
q != top(ar_ptr) && inuse(q) && (long)chunksize(q) > 0;
|
||
q = next_chunk(q))
|
||
check_inuse_chunk(ar_ptr, q);
|
||
#endif
|
||
avail += chunksize(p);
|
||
navail++;
|
||
}
|
||
}
|
||
|
||
mi->arena = ar_ptr->size;
|
||
mi->ordblks = navail;
|
||
mi->smblks = mi->usmblks = mi->fsmblks = 0; /* clear unused fields */
|
||
mi->uordblks = ar_ptr->size - avail;
|
||
mi->fordblks = avail;
|
||
mi->hblks = n_mmaps;
|
||
mi->hblkhd = mmapped_mem;
|
||
mi->keepcost = chunksize(top(ar_ptr));
|
||
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
}
|
||
|
||
#if !defined(NO_THREADS) && MALLOC_DEBUG > 1
|
||
|
||
/* Print the complete contents of a single heap to stderr. */
|
||
|
||
static void
|
||
#if __STD_C
|
||
dump_heap(heap_info *heap)
|
||
#else
|
||
dump_heap(heap) heap_info *heap;
|
||
#endif
|
||
{
|
||
char *ptr;
|
||
mchunkptr p;
|
||
|
||
fprintf(stderr, "Heap %p, size %10lx:\n", heap, (long)heap->size);
|
||
ptr = (heap->ar_ptr != (arena*)(heap+1)) ?
|
||
(char*)(heap + 1) : (char*)(heap + 1) + sizeof(arena);
|
||
p = (mchunkptr)(((unsigned long)ptr + MALLOC_ALIGN_MASK) &
|
||
~MALLOC_ALIGN_MASK);
|
||
for(;;) {
|
||
fprintf(stderr, "chunk %p size %10lx", p, (long)p->size);
|
||
if(p == top(heap->ar_ptr)) {
|
||
fprintf(stderr, " (top)\n");
|
||
break;
|
||
} else if(p->size == (0|PREV_INUSE)) {
|
||
fprintf(stderr, " (fence)\n");
|
||
break;
|
||
}
|
||
fprintf(stderr, "\n");
|
||
p = next_chunk(p);
|
||
}
|
||
}
|
||
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
|
||
malloc_stats:
|
||
|
||
For all arenas separately and in total, prints on stderr the
|
||
amount of space obtained from the system, and the current number
|
||
of bytes allocated via malloc (or realloc, etc) but not yet
|
||
freed. (Note that this is the number of bytes allocated, not the
|
||
number requested. It will be larger than the number requested
|
||
because of alignment and bookkeeping overhead.) When not compiled
|
||
for multiple threads, the maximum amount of allocated memory
|
||
(which may be more than current if malloc_trim and/or munmap got
|
||
called) is also reported. When using mmap(), prints the maximum
|
||
number of simultaneous mmap regions used, too.
|
||
|
||
*/
|
||
|
||
void mALLOC_STATs()
|
||
{
|
||
int i;
|
||
arena *ar_ptr;
|
||
struct mallinfo mi;
|
||
unsigned int in_use_b = mmapped_mem, system_b = in_use_b;
|
||
#if THREAD_STATS
|
||
long stat_lock_direct = 0, stat_lock_loop = 0, stat_lock_wait = 0;
|
||
#endif
|
||
|
||
for(i=0, ar_ptr = &main_arena;; i++) {
|
||
malloc_update_mallinfo(ar_ptr, &mi);
|
||
fprintf(stderr, "Arena %d:\n", i);
|
||
fprintf(stderr, "system bytes = %10u\n", (unsigned int)mi.arena);
|
||
fprintf(stderr, "in use bytes = %10u\n", (unsigned int)mi.uordblks);
|
||
system_b += mi.arena;
|
||
in_use_b += mi.uordblks;
|
||
#if THREAD_STATS
|
||
stat_lock_direct += ar_ptr->stat_lock_direct;
|
||
stat_lock_loop += ar_ptr->stat_lock_loop;
|
||
stat_lock_wait += ar_ptr->stat_lock_wait;
|
||
#endif
|
||
#if !defined(NO_THREADS) && MALLOC_DEBUG > 1
|
||
if(ar_ptr != &main_arena) {
|
||
heap_info *heap;
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
heap = heap_for_ptr(top(ar_ptr));
|
||
while(heap) { dump_heap(heap); heap = heap->prev; }
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
}
|
||
#endif
|
||
ar_ptr = ar_ptr->next;
|
||
if(ar_ptr == &main_arena) break;
|
||
}
|
||
#if HAVE_MMAP
|
||
fprintf(stderr, "Total (incl. mmap):\n");
|
||
#else
|
||
fprintf(stderr, "Total:\n");
|
||
#endif
|
||
fprintf(stderr, "system bytes = %10u\n", system_b);
|
||
fprintf(stderr, "in use bytes = %10u\n", in_use_b);
|
||
#ifdef NO_THREADS
|
||
fprintf(stderr, "max system bytes = %10u\n", (unsigned int)max_total_mem);
|
||
#endif
|
||
#if HAVE_MMAP
|
||
fprintf(stderr, "max mmap regions = %10u\n", (unsigned int)max_n_mmaps);
|
||
fprintf(stderr, "max mmap bytes = %10lu\n", max_mmapped_mem);
|
||
#endif
|
||
#if THREAD_STATS
|
||
fprintf(stderr, "heaps created = %10d\n", stat_n_heaps);
|
||
fprintf(stderr, "locked directly = %10ld\n", stat_lock_direct);
|
||
fprintf(stderr, "locked in loop = %10ld\n", stat_lock_loop);
|
||
fprintf(stderr, "locked waiting = %10ld\n", stat_lock_wait);
|
||
fprintf(stderr, "locked total = %10ld\n",
|
||
stat_lock_direct + stat_lock_loop + stat_lock_wait);
|
||
#endif
|
||
}
|
||
|
||
/*
|
||
mallinfo returns a copy of updated current mallinfo.
|
||
The information reported is for the arena last used by the thread.
|
||
*/
|
||
|
||
struct mallinfo mALLINFo()
|
||
{
|
||
struct mallinfo mi;
|
||
Void_t *vptr = NULL;
|
||
|
||
#ifndef NO_THREADS
|
||
tsd_getspecific(arena_key, vptr);
|
||
#endif
|
||
malloc_update_mallinfo((vptr ? (arena*)vptr : &main_arena), &mi);
|
||
return mi;
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
mallopt:
|
||
|
||
mallopt is the general SVID/XPG interface to tunable parameters.
|
||
The format is to provide a (parameter-number, parameter-value) pair.
|
||
mallopt then sets the corresponding parameter to the argument
|
||
value if it can (i.e., so long as the value is meaningful),
|
||
and returns 1 if successful else 0.
|
||
|
||
See descriptions of tunable parameters above.
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
int mALLOPt(int param_number, int value)
|
||
#else
|
||
int mALLOPt(param_number, value) int param_number; int value;
|
||
#endif
|
||
{
|
||
switch(param_number)
|
||
{
|
||
case M_TRIM_THRESHOLD:
|
||
trim_threshold = value; return 1;
|
||
case M_TOP_PAD:
|
||
top_pad = value; return 1;
|
||
case M_MMAP_THRESHOLD:
|
||
#ifndef NO_THREADS
|
||
/* Forbid setting the threshold too high. */
|
||
if((unsigned long)value > HEAP_MAX_SIZE/2) return 0;
|
||
#endif
|
||
mmap_threshold = value; return 1;
|
||
case M_MMAP_MAX:
|
||
#if HAVE_MMAP
|
||
n_mmaps_max = value; return 1;
|
||
#else
|
||
if (value != 0) return 0; else n_mmaps_max = value; return 1;
|
||
#endif
|
||
case M_CHECK_ACTION:
|
||
check_action = value; return 1;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
|
||
|
||
/* Get/set state: malloc_get_state() records the current state of all
|
||
malloc variables (_except_ for the actual heap contents and `hook'
|
||
function pointers) in a system dependent, opaque data structure.
|
||
This data structure is dynamically allocated and can be free()d
|
||
after use. malloc_set_state() restores the state of all malloc
|
||
variables to the previously obtained state. This is especially
|
||
useful when using this malloc as part of a shared library, and when
|
||
the heap contents are saved/restored via some other method. The
|
||
primary example for this is GNU Emacs with its `dumping' procedure.
|
||
`Hook' function pointers are never saved or restored by these
|
||
functions. */
|
||
|
||
#define MALLOC_STATE_MAGIC 0x444c4541l
|
||
#define MALLOC_STATE_VERSION (0*0x100l + 1l) /* major*0x100 + minor */
|
||
|
||
struct malloc_state {
|
||
long magic;
|
||
long version;
|
||
mbinptr av[NAV * 2 + 2];
|
||
char* sbrk_base;
|
||
int sbrked_mem_bytes;
|
||
unsigned long trim_threshold;
|
||
unsigned long top_pad;
|
||
unsigned int n_mmaps_max;
|
||
unsigned long mmap_threshold;
|
||
int check_action;
|
||
unsigned long max_sbrked_mem;
|
||
unsigned long max_total_mem;
|
||
unsigned int n_mmaps;
|
||
unsigned int max_n_mmaps;
|
||
unsigned long mmapped_mem;
|
||
unsigned long max_mmapped_mem;
|
||
int using_malloc_checking;
|
||
};
|
||
|
||
Void_t*
|
||
mALLOC_GET_STATe()
|
||
{
|
||
struct malloc_state* ms;
|
||
int i;
|
||
mbinptr b;
|
||
|
||
ms = (struct malloc_state*)mALLOc(sizeof(*ms));
|
||
if (!ms)
|
||
return 0;
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
ms->magic = MALLOC_STATE_MAGIC;
|
||
ms->version = MALLOC_STATE_VERSION;
|
||
ms->av[0] = main_arena.av[0];
|
||
ms->av[1] = main_arena.av[1];
|
||
for(i=0; i<NAV; i++) {
|
||
b = bin_at(&main_arena, i);
|
||
if(first(b) == b)
|
||
ms->av[2*i+2] = ms->av[2*i+3] = 0; /* empty bin (or initial top) */
|
||
else {
|
||
ms->av[2*i+2] = first(b);
|
||
ms->av[2*i+3] = last(b);
|
||
}
|
||
}
|
||
ms->sbrk_base = sbrk_base;
|
||
ms->sbrked_mem_bytes = sbrked_mem;
|
||
ms->trim_threshold = trim_threshold;
|
||
ms->top_pad = top_pad;
|
||
ms->n_mmaps_max = n_mmaps_max;
|
||
ms->mmap_threshold = mmap_threshold;
|
||
ms->check_action = check_action;
|
||
ms->max_sbrked_mem = max_sbrked_mem;
|
||
#ifdef NO_THREADS
|
||
ms->max_total_mem = max_total_mem;
|
||
#else
|
||
ms->max_total_mem = 0;
|
||
#endif
|
||
ms->n_mmaps = n_mmaps;
|
||
ms->max_n_mmaps = max_n_mmaps;
|
||
ms->mmapped_mem = mmapped_mem;
|
||
ms->max_mmapped_mem = max_mmapped_mem;
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
ms->using_malloc_checking = using_malloc_checking;
|
||
#else
|
||
ms->using_malloc_checking = 0;
|
||
#endif
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
return (Void_t*)ms;
|
||
}
|
||
|
||
int
|
||
#if __STD_C
|
||
mALLOC_SET_STATe(Void_t* msptr)
|
||
#else
|
||
mALLOC_SET_STATe(msptr) Void_t* msptr;
|
||
#endif
|
||
{
|
||
struct malloc_state* ms = (struct malloc_state*)msptr;
|
||
int i;
|
||
mbinptr b;
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
disallow_malloc_check = 1;
|
||
#endif
|
||
ptmalloc_init();
|
||
if(ms->magic != MALLOC_STATE_MAGIC) return -1;
|
||
/* Must fail if the major version is too high. */
|
||
if((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl)) return -2;
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
main_arena.av[0] = ms->av[0];
|
||
main_arena.av[1] = ms->av[1];
|
||
for(i=0; i<NAV; i++) {
|
||
b = bin_at(&main_arena, i);
|
||
if(ms->av[2*i+2] == 0)
|
||
first(b) = last(b) = b;
|
||
else {
|
||
first(b) = ms->av[2*i+2];
|
||
last(b) = ms->av[2*i+3];
|
||
if(i > 0) {
|
||
/* Make sure the links to the `av'-bins in the heap are correct. */
|
||
first(b)->bk = b;
|
||
last(b)->fd = b;
|
||
}
|
||
}
|
||
}
|
||
sbrk_base = ms->sbrk_base;
|
||
sbrked_mem = ms->sbrked_mem_bytes;
|
||
trim_threshold = ms->trim_threshold;
|
||
top_pad = ms->top_pad;
|
||
n_mmaps_max = ms->n_mmaps_max;
|
||
mmap_threshold = ms->mmap_threshold;
|
||
check_action = ms->check_action;
|
||
max_sbrked_mem = ms->max_sbrked_mem;
|
||
#ifdef NO_THREADS
|
||
max_total_mem = ms->max_total_mem;
|
||
#endif
|
||
n_mmaps = ms->n_mmaps;
|
||
max_n_mmaps = ms->max_n_mmaps;
|
||
mmapped_mem = ms->mmapped_mem;
|
||
max_mmapped_mem = ms->max_mmapped_mem;
|
||
/* add version-dependent code here */
|
||
if (ms->version >= 1) {
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
/* Check whether it is safe to enable malloc checking. */
|
||
if (ms->using_malloc_checking && !using_malloc_checking &&
|
||
!disallow_malloc_check)
|
||
__malloc_check_init ();
|
||
#endif
|
||
}
|
||
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
return 0;
|
||
}
|
||
|
||
|
||
|
||
#if defined _LIBC || defined MALLOC_HOOKS
|
||
|
||
/* A simple, standard set of debugging hooks. Overhead is `only' one
|
||
byte per chunk; still this will catch most cases of double frees or
|
||
overruns. The goal here is to avoid obscure crashes due to invalid
|
||
usage, unlike in the MALLOC_DEBUG code. */
|
||
|
||
#define MAGICBYTE(p) ( ( ((size_t)p >> 3) ^ ((size_t)p >> 11)) & 0xFF )
|
||
|
||
/* Instrument a chunk with overrun detector byte(s) and convert it
|
||
into a user pointer with requested size sz. */
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
chunk2mem_check(mchunkptr p, size_t sz)
|
||
#else
|
||
chunk2mem_check(p, sz) mchunkptr p; size_t sz;
|
||
#endif
|
||
{
|
||
unsigned char* m_ptr = (unsigned char*)chunk2mem(p);
|
||
size_t i;
|
||
|
||
for(i = chunksize(p) - (chunk_is_mmapped(p) ? 2*SIZE_SZ+1 : SIZE_SZ+1);
|
||
i > sz;
|
||
i -= 0xFF) {
|
||
if(i-sz < 0x100) {
|
||
m_ptr[i] = (unsigned char)(i-sz);
|
||
break;
|
||
}
|
||
m_ptr[i] = 0xFF;
|
||
}
|
||
m_ptr[sz] = MAGICBYTE(p);
|
||
return (Void_t*)m_ptr;
|
||
}
|
||
|
||
/* Convert a pointer to be free()d or realloc()ed to a valid chunk
|
||
pointer. If the provided pointer is not valid, return NULL. */
|
||
|
||
static mchunkptr
|
||
internal_function
|
||
#if __STD_C
|
||
mem2chunk_check(Void_t* mem)
|
||
#else
|
||
mem2chunk_check(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
INTERNAL_SIZE_T sz, c;
|
||
unsigned char magic;
|
||
|
||
p = mem2chunk(mem);
|
||
if(!aligned_OK(p)) return NULL;
|
||
if( (char*)p>=sbrk_base && (char*)p<(sbrk_base+sbrked_mem) ) {
|
||
/* Must be a chunk in conventional heap memory. */
|
||
if(chunk_is_mmapped(p) ||
|
||
( (sz = chunksize(p)), ((char*)p + sz)>=(sbrk_base+sbrked_mem) ) ||
|
||
sz<MINSIZE || sz&MALLOC_ALIGN_MASK || !inuse(p) ||
|
||
( !prev_inuse(p) && (p->prev_size&MALLOC_ALIGN_MASK ||
|
||
(long)prev_chunk(p)<(long)sbrk_base ||
|
||
next_chunk(prev_chunk(p))!=p) ))
|
||
return NULL;
|
||
magic = MAGICBYTE(p);
|
||
for(sz += SIZE_SZ-1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) {
|
||
if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL;
|
||
}
|
||
((unsigned char*)p)[sz] ^= 0xFF;
|
||
} else {
|
||
unsigned long offset, page_mask = malloc_getpagesize-1;
|
||
|
||
/* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two
|
||
alignment relative to the beginning of a page. Check this
|
||
first. */
|
||
offset = (unsigned long)mem & page_mask;
|
||
if((offset!=MALLOC_ALIGNMENT && offset!=0 && offset!=0x10 &&
|
||
offset!=0x20 && offset!=0x40 && offset!=0x80 && offset!=0x100 &&
|
||
offset!=0x200 && offset!=0x400 && offset!=0x800 && offset!=0x1000 &&
|
||
offset<0x2000) ||
|
||
!chunk_is_mmapped(p) || (p->size & PREV_INUSE) ||
|
||
( (((unsigned long)p - p->prev_size) & page_mask) != 0 ) ||
|
||
( (sz = chunksize(p)), ((p->prev_size + sz) & page_mask) != 0 ) )
|
||
return NULL;
|
||
magic = MAGICBYTE(p);
|
||
for(sz -= 1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) {
|
||
if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL;
|
||
}
|
||
((unsigned char*)p)[sz] ^= 0xFF;
|
||
}
|
||
return p;
|
||
}
|
||
|
||
/* Check for corruption of the top chunk, and try to recover if
|
||
necessary. */
|
||
|
||
static int
|
||
#if __STD_C
|
||
top_check(void)
|
||
#else
|
||
top_check()
|
||
#endif
|
||
{
|
||
mchunkptr t = top(&main_arena);
|
||
char* brk, * new_brk;
|
||
INTERNAL_SIZE_T front_misalign, sbrk_size;
|
||
unsigned long pagesz = malloc_getpagesize;
|
||
|
||
if((char*)t + chunksize(t) == sbrk_base + sbrked_mem ||
|
||
t == initial_top(&main_arena)) return 0;
|
||
|
||
switch(check_action) {
|
||
case 1:
|
||
fprintf(stderr, "malloc: top chunk is corrupt\n");
|
||
break;
|
||
case 2:
|
||
abort();
|
||
}
|
||
/* Try to set up a new top chunk. */
|
||
brk = MORECORE(0);
|
||
front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK;
|
||
if (front_misalign > 0)
|
||
front_misalign = MALLOC_ALIGNMENT - front_misalign;
|
||
sbrk_size = front_misalign + top_pad + MINSIZE;
|
||
sbrk_size += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1));
|
||
new_brk = (char*)(MORECORE (sbrk_size));
|
||
if (new_brk == (char*)(MORECORE_FAILURE)) return -1;
|
||
sbrked_mem = (new_brk - sbrk_base) + sbrk_size;
|
||
|
||
top(&main_arena) = (mchunkptr)(brk + front_misalign);
|
||
set_head(top(&main_arena), (sbrk_size - front_misalign) | PREV_INUSE);
|
||
|
||
return 0;
|
||
}
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
malloc_check(size_t sz, const Void_t *caller)
|
||
#else
|
||
malloc_check(sz, caller) size_t sz; const Void_t *caller;
|
||
#endif
|
||
{
|
||
mchunkptr victim;
|
||
INTERNAL_SIZE_T nb = request2size(sz + 1);
|
||
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
victim = (top_check() >= 0) ? chunk_alloc(&main_arena, nb) : NULL;
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
if(!victim) return NULL;
|
||
return chunk2mem_check(victim, sz);
|
||
}
|
||
|
||
static void
|
||
#if __STD_C
|
||
free_check(Void_t* mem, const Void_t *caller)
|
||
#else
|
||
free_check(mem, caller) Void_t* mem; const Void_t *caller;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
|
||
if(!mem) return;
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
p = mem2chunk_check(mem);
|
||
if(!p) {
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
switch(check_action) {
|
||
case 1:
|
||
fprintf(stderr, "free(): invalid pointer %p!\n", mem);
|
||
break;
|
||
case 2:
|
||
abort();
|
||
}
|
||
return;
|
||
}
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(p)) {
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
munmap_chunk(p);
|
||
return;
|
||
}
|
||
#endif
|
||
#if 0 /* Erase freed memory. */
|
||
memset(mem, 0, chunksize(p) - (SIZE_SZ+1));
|
||
#endif
|
||
chunk_free(&main_arena, p);
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
}
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
realloc_check(Void_t* oldmem, size_t bytes, const Void_t *caller)
|
||
#else
|
||
realloc_check(oldmem, bytes, caller)
|
||
Void_t* oldmem; size_t bytes; const Void_t *caller;
|
||
#endif
|
||
{
|
||
mchunkptr oldp, newp;
|
||
INTERNAL_SIZE_T nb, oldsize;
|
||
|
||
if (oldmem == 0) return malloc_check(bytes, NULL);
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
oldp = mem2chunk_check(oldmem);
|
||
if(!oldp) {
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
switch(check_action) {
|
||
case 1:
|
||
fprintf(stderr, "realloc(): invalid pointer %p!\n", oldmem);
|
||
break;
|
||
case 2:
|
||
abort();
|
||
}
|
||
return malloc_check(bytes, NULL);
|
||
}
|
||
oldsize = chunksize(oldp);
|
||
|
||
nb = request2size(bytes+1);
|
||
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(oldp)) {
|
||
#if HAVE_MREMAP
|
||
newp = mremap_chunk(oldp, nb);
|
||
if(!newp) {
|
||
#endif
|
||
/* Note the extra SIZE_SZ overhead. */
|
||
if(oldsize - SIZE_SZ >= nb) newp = oldp; /* do nothing */
|
||
else {
|
||
/* Must alloc, copy, free. */
|
||
newp = (top_check() >= 0) ? chunk_alloc(&main_arena, nb) : NULL;
|
||
if (newp) {
|
||
MALLOC_COPY(chunk2mem(newp), oldmem, oldsize - 2*SIZE_SZ);
|
||
munmap_chunk(oldp);
|
||
}
|
||
}
|
||
#if HAVE_MREMAP
|
||
}
|
||
#endif
|
||
} else {
|
||
#endif /* HAVE_MMAP */
|
||
newp = (top_check() >= 0) ?
|
||
chunk_realloc(&main_arena, oldp, oldsize, nb) : NULL;
|
||
#if 0 /* Erase freed memory. */
|
||
nb = chunksize(newp);
|
||
if(oldp<newp || oldp>=chunk_at_offset(newp, nb)) {
|
||
memset((char*)oldmem + 2*sizeof(mbinptr), 0,
|
||
oldsize - (2*sizeof(mbinptr)+2*SIZE_SZ+1));
|
||
} else if(nb > oldsize+SIZE_SZ) {
|
||
memset((char*)chunk2mem(newp) + oldsize, 0, nb - (oldsize+SIZE_SZ));
|
||
}
|
||
#endif
|
||
#if HAVE_MMAP
|
||
}
|
||
#endif
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
|
||
if(!newp) return NULL;
|
||
return chunk2mem_check(newp, bytes);
|
||
}
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
memalign_check(size_t alignment, size_t bytes, const Void_t *caller)
|
||
#else
|
||
memalign_check(alignment, bytes, caller)
|
||
size_t alignment; size_t bytes; const Void_t *caller;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T nb;
|
||
mchunkptr p;
|
||
|
||
if (alignment <= MALLOC_ALIGNMENT) return malloc_check(bytes, NULL);
|
||
if (alignment < MINSIZE) alignment = MINSIZE;
|
||
|
||
nb = request2size(bytes+1);
|
||
(void)mutex_lock(&main_arena.mutex);
|
||
p = (top_check() >= 0) ? chunk_align(&main_arena, nb, alignment) : NULL;
|
||
(void)mutex_unlock(&main_arena.mutex);
|
||
if(!p) return NULL;
|
||
return chunk2mem_check(p, bytes);
|
||
}
|
||
|
||
#ifndef NO_THREADS
|
||
|
||
/* The following hooks are used when the global initialization in
|
||
ptmalloc_init() hasn't completed yet. */
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
malloc_starter(size_t sz, const Void_t *caller)
|
||
#else
|
||
malloc_starter(sz, caller) size_t sz; const Void_t *caller;
|
||
#endif
|
||
{
|
||
mchunkptr victim = chunk_alloc(&main_arena, request2size(sz));
|
||
|
||
return victim ? chunk2mem(victim) : 0;
|
||
}
|
||
|
||
static void
|
||
#if __STD_C
|
||
free_starter(Void_t* mem, const Void_t *caller)
|
||
#else
|
||
free_starter(mem, caller) Void_t* mem; const Void_t *caller;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
|
||
if(!mem) return;
|
||
p = mem2chunk(mem);
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(p)) {
|
||
munmap_chunk(p);
|
||
return;
|
||
}
|
||
#endif
|
||
chunk_free(&main_arena, p);
|
||
}
|
||
|
||
/* The following hooks are used while the `atfork' handling mechanism
|
||
is active. */
|
||
|
||
static Void_t*
|
||
#if __STD_C
|
||
malloc_atfork (size_t sz, const Void_t *caller)
|
||
#else
|
||
malloc_atfork(sz, caller) size_t sz; const Void_t *caller;
|
||
#endif
|
||
{
|
||
Void_t *vptr = NULL;
|
||
|
||
tsd_getspecific(arena_key, vptr);
|
||
if(!vptr) {
|
||
mchunkptr victim = chunk_alloc(&main_arena, request2size(sz));
|
||
return victim ? chunk2mem(victim) : 0;
|
||
} else {
|
||
/* Suspend the thread until the `atfork' handlers have completed.
|
||
By that time, the hooks will have been reset as well, so that
|
||
mALLOc() can be used again. */
|
||
(void)mutex_lock(&list_lock);
|
||
(void)mutex_unlock(&list_lock);
|
||
return mALLOc(sz);
|
||
}
|
||
}
|
||
|
||
static void
|
||
#if __STD_C
|
||
free_atfork(Void_t* mem, const Void_t *caller)
|
||
#else
|
||
free_atfork(mem, caller) Void_t* mem; const Void_t *caller;
|
||
#endif
|
||
{
|
||
Void_t *vptr = NULL;
|
||
arena *ar_ptr;
|
||
mchunkptr p; /* chunk corresponding to mem */
|
||
|
||
if (mem == 0) /* free(0) has no effect */
|
||
return;
|
||
|
||
p = mem2chunk(mem);
|
||
|
||
#if HAVE_MMAP
|
||
if (chunk_is_mmapped(p)) /* release mmapped memory. */
|
||
{
|
||
munmap_chunk(p);
|
||
return;
|
||
}
|
||
#endif
|
||
|
||
ar_ptr = arena_for_ptr(p);
|
||
tsd_getspecific(arena_key, vptr);
|
||
if(vptr)
|
||
(void)mutex_lock(&ar_ptr->mutex);
|
||
chunk_free(ar_ptr, p);
|
||
if(vptr)
|
||
(void)mutex_unlock(&ar_ptr->mutex);
|
||
}
|
||
|
||
#endif
|
||
|
||
#endif /* defined _LIBC || defined MALLOC_HOOKS */
|
||
|
||
|
||
|
||
#ifdef _LIBC
|
||
weak_alias (__libc_calloc, __calloc) weak_alias (__libc_calloc, calloc)
|
||
weak_alias (__libc_free, __cfree) weak_alias (__libc_free, cfree)
|
||
weak_alias (__libc_free, __free) weak_alias (__libc_free, free)
|
||
weak_alias (__libc_malloc, __malloc) weak_alias (__libc_malloc, malloc)
|
||
weak_alias (__libc_memalign, __memalign) weak_alias (__libc_memalign, memalign)
|
||
weak_alias (__libc_realloc, __realloc) weak_alias (__libc_realloc, realloc)
|
||
weak_alias (__libc_valloc, __valloc) weak_alias (__libc_valloc, valloc)
|
||
weak_alias (__libc_pvalloc, __pvalloc) weak_alias (__libc_pvalloc, pvalloc)
|
||
weak_alias (__libc_mallinfo, __mallinfo) weak_alias (__libc_mallinfo, mallinfo)
|
||
weak_alias (__libc_mallopt, __mallopt) weak_alias (__libc_mallopt, mallopt)
|
||
|
||
weak_alias (__malloc_stats, malloc_stats)
|
||
weak_alias (__malloc_usable_size, malloc_usable_size)
|
||
weak_alias (__malloc_trim, malloc_trim)
|
||
weak_alias (__malloc_get_state, malloc_get_state)
|
||
weak_alias (__malloc_set_state, malloc_set_state)
|
||
#endif
|
||
|
||
/*
|
||
|
||
History:
|
||
|
||
V2.6.4-pt3 Thu Feb 20 1997 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de)
|
||
* Added malloc_get/set_state() (mainly for use in GNU emacs),
|
||
using interface from Marcus Daniels
|
||
* All parameters are now adjustable via environment variables
|
||
|
||
V2.6.4-pt2 Sat Dec 14 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de)
|
||
* Added debugging hooks
|
||
* Fixed possible deadlock in realloc() when out of memory
|
||
* Don't pollute namespace in glibc: use __getpagesize, __mmap, etc.
|
||
|
||
V2.6.4-pt Wed Dec 4 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de)
|
||
* Very minor updates from the released 2.6.4 version.
|
||
* Trimmed include file down to exported data structures.
|
||
* Changes from H.J. Lu for glibc-2.0.
|
||
|
||
V2.6.3i-pt Sep 16 1996 Wolfram Gloger (wmglo@dent.med.uni-muenchen.de)
|
||
* Many changes for multiple threads
|
||
* Introduced arenas and heaps
|
||
|
||
V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee)
|
||
* Added pvalloc, as recommended by H.J. Liu
|
||
* Added 64bit pointer support mainly from Wolfram Gloger
|
||
* Added anonymously donated WIN32 sbrk emulation
|
||
* Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
|
||
* malloc_extend_top: fix mask error that caused wastage after
|
||
foreign sbrks
|
||
* Add linux mremap support code from HJ Liu
|
||
|
||
V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee)
|
||
* Integrated most documentation with the code.
|
||
* Add support for mmap, with help from
|
||
Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
||
* Use last_remainder in more cases.
|
||
* Pack bins using idea from colin@nyx10.cs.du.edu
|
||
* Use ordered bins instead of best-fit threshold
|
||
* Eliminate block-local decls to simplify tracing and debugging.
|
||
* Support another case of realloc via move into top
|
||
* Fix error occurring when initial sbrk_base not word-aligned.
|
||
* Rely on page size for units instead of SBRK_UNIT to
|
||
avoid surprises about sbrk alignment conventions.
|
||
* Add mallinfo, mallopt. Thanks to Raymond Nijssen
|
||
(raymond@es.ele.tue.nl) for the suggestion.
|
||
* Add `pad' argument to malloc_trim and top_pad mallopt parameter.
|
||
* More precautions for cases where other routines call sbrk,
|
||
courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
||
* Added macros etc., allowing use in linux libc from
|
||
H.J. Lu (hjl@gnu.ai.mit.edu)
|
||
* Inverted this history list
|
||
|
||
V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee)
|
||
* Re-tuned and fixed to behave more nicely with V2.6.0 changes.
|
||
* Removed all preallocation code since under current scheme
|
||
the work required to undo bad preallocations exceeds
|
||
the work saved in good cases for most test programs.
|
||
* No longer use return list or unconsolidated bins since
|
||
no scheme using them consistently outperforms those that don't
|
||
given above changes.
|
||
* Use best fit for very large chunks to prevent some worst-cases.
|
||
* Added some support for debugging
|
||
|
||
V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee)
|
||
* Removed footers when chunks are in use. Thanks to
|
||
Paul Wilson (wilson@cs.texas.edu) for the suggestion.
|
||
|
||
V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee)
|
||
* Added malloc_trim, with help from Wolfram Gloger
|
||
(wmglo@Dent.MED.Uni-Muenchen.DE).
|
||
|
||
V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g)
|
||
|
||
V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g)
|
||
* realloc: try to expand in both directions
|
||
* malloc: swap order of clean-bin strategy;
|
||
* realloc: only conditionally expand backwards
|
||
* Try not to scavenge used bins
|
||
* Use bin counts as a guide to preallocation
|
||
* Occasionally bin return list chunks in first scan
|
||
* Add a few optimizations from colin@nyx10.cs.du.edu
|
||
|
||
V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g)
|
||
* faster bin computation & slightly different binning
|
||
* merged all consolidations to one part of malloc proper
|
||
(eliminating old malloc_find_space & malloc_clean_bin)
|
||
* Scan 2 returns chunks (not just 1)
|
||
* Propagate failure in realloc if malloc returns 0
|
||
* Add stuff to allow compilation on non-ANSI compilers
|
||
from kpv@research.att.com
|
||
|
||
V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu)
|
||
* removed potential for odd address access in prev_chunk
|
||
* removed dependency on getpagesize.h
|
||
* misc cosmetics and a bit more internal documentation
|
||
* anticosmetics: mangled names in macros to evade debugger strangeness
|
||
* tested on sparc, hp-700, dec-mips, rs6000
|
||
with gcc & native cc (hp, dec only) allowing
|
||
Detlefs & Zorn comparison study (in SIGPLAN Notices.)
|
||
|
||
Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu)
|
||
* Based loosely on libg++-1.2X malloc. (It retains some of the overall
|
||
structure of old version, but most details differ.)
|
||
|
||
*/
|