mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 02:33:36 +08:00
38 lines
1.4 KiB
C
38 lines
1.4 KiB
C
/* Macros for copying by pages; used in memcpy, memmove.
|
|
Copyright (C) 1995-2017 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* The macro PAGE_COPY_FWD_MAYBE defined in memcopy.h is used in memmove if the
|
|
PAGE_COPY_THRESHOLD macro is set to a non-zero value. The default is 0,
|
|
that is copying by pages is not implemented.
|
|
|
|
System-specific pagecopy.h files that want to support page copying should
|
|
define these macros:
|
|
|
|
PAGE_COPY_THRESHOLD
|
|
-- A non-zero minimum size for which virtual copying by pages is worthwhile.
|
|
|
|
PAGE_SIZE
|
|
-- Size of a page.
|
|
|
|
PAGE_COPY_FWD (dstp, srcp, nbytes_left, nbytes)
|
|
-- Macro to perform the virtual copy operation.
|
|
The pointers will be aligned to PAGE_SIZE bytes.
|
|
*/
|
|
|
|
#define PAGE_COPY_THRESHOLD 0
|