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Pedro Alves e8032dde10 Push pruning old threads down to the target
When GDB wants to sync the thread list with the target's (e.g., due to
"info threads"), it calls update_thread_list:

 update_thread_list (void)
 {
   prune_threads ();
   target_find_new_threads ();
   update_threads_executing ();
 }

And then prune_threads does:

 prune_threads (void)
 {
   struct thread_info *tp, *next;

   for (tp = thread_list; tp; tp = next)
     {
       next = tp->next;
       if (!thread_alive (tp))
	 delete_thread (tp->ptid);
     }
 }

Calling thread_live on each thread one by one is expensive.

E.g., on Linux, it ends up doing kill(SIG0) once for each thread.  Not
a big deal, but still a bunch of syscalls...

With the remote target, it's cumbersome.  That thread_alive call ends
up generating one T packet per thread:

 Sending packet: $Tp2141.2150#82...Packet received: OK
 Sending packet: $Tp2141.214f#b7...Packet received: OK
 Sending packet: $Tp2141.2141#82...Packet received: OK
 Sending packet: $qXfer:threads:read::0,fff#03...Packet received: l<threads>\n<thread id="p2141.2141" core="2"/>\n<thread id="p2141.214f" core="1"/>\n<thread id="p2141.2150" core="2"/>\n</threads>\n

That seems a bit silly when target_find_new_threads method
implementations will always fetch the whole current set of target
threads, and then add those that are not in GDB's thread list, to
GDB's thread list.

This patch thus pushes down the responsibility of pruning dead threads
to the target_find_new_threads method instead, so a target may
implement pruning dead threads however it wants.

Once we do that, target_find_new_threads becomes a misnomer, so the
patch renames it to target_update_thread_list.

The patch doesn't attempt to do any optimization to any target yet.
It simply exports prune_threads, and makes all implementations of
target_update_thread_list call that.  It's meant to be a no-op.

gdb/
2014-10-15  Pedro Alves  <palves@redhat.com>

	* ada-tasks.c (print_ada_task_info, task_command_1): Adjust.
	* bsd-uthread.c (bsd_uthread_find_new_threads): Rename to ...
	(bsd_uthread_update_thread_list): ... this.  Call prune_threads.
	(bsd_uthread_target): Adjust.
	* corelow.c (core_open): Adjust.
	* dec-thread.c (dec_thread_find_new_threads): Update comment.
	(dec_thread_update_thread_list): New function.
	(init_dec_thread_ops): Adjust.
	* gdbthread.h (prune_threads): New declaration.
	* linux-thread-db.c (thread_db_find_new_threads): Rename to ...
	(thread_db_update_thread_list): ... this.  Call prune_threads.
	(init_thread_db_ops): Adjust.
	* nto-procfs.c (procfs_find_new_threads): Rename to ...
	(procfs_update_thread_list): ... this.  Call prune_threads.
	(procfs_attach, procfs_create_inferior, init_procfs_targets):
	Adjust.
	* obsd-nat.c (obsd_find_new_threads): Rename to ...
	(obsd_update_thread_list): ... this.  Call prune_threads.
	(obsd_add_target): Adjust.
	* procfs.c (procfs_target): Adjust.
	(procfs_notice_thread): Update comment.
	(procfs_find_new_threads): Rename to ...
	(procfs_update_thread_list): ... this.  Call prune_threads.
	* ravenscar-thread.c (ravenscar_update_inferior_ptid): Update
	comment.
	(ravenscar_wait): Adjust.
	(ravenscar_find_new_threads): Rename to ...
	(ravenscar_update_thread_list): ... this.  Call prune_threads.
	(init_ravenscar_thread_ops): Adjust.
	* record-btrace.c (record_btrace_find_new_threads): Rename to ...
	(record_btrace_update_thread_list): ... this.  Adjust comment.
	(init_record_btrace_ops): Adjust.
	* remote.c (remote_threads_info): Rename to ...
	(remote_update_thread_list): ... this.  Call prune_threads.
	(remote_start_remote, extended_remote_attach_1, init_remote_ops):
	Adjust.
	* sol-thread.c (check_for_thread_db): Adjust.
	(sol_find_new_threads_callback): Rename to ...
	(sol_update_thread_list_callback): ... this.
	(sol_find_new_threads): Rename to ...
	(sol_update_thread_list): ... this.  Call prune_threads.  Adjust.
	(sol_get_ada_task_ptid, init_sol_thread_ops): Adjust.
	* target-delegates.c: Regenerate.
	* target.c (target_find_new_threads): Rename to ...
	(target_update_thread_list): ... this.
	* target.h (struct target_ops): Rename to_find_new_threads field
	to to_update_thread_list.
	(target_find_new_threads): Rename to ...
	(target_update_thread_list): ... this.
	* thread.c (prune_threads): Make extern.
	(update_thread_list): Adjust.
2014-10-15 22:54:13 +01:00
bfd Merge bfd_find_nearest_line variants 2014-10-15 22:55:25 +10:30
binutils Bump bfd version. 2014-10-15 10:21:25 +02:00
config Fix --diable-shared --enable-plugins build breakage 2014-08-19 21:59:56 +09:30
cpu or1k: add missing l.msync, l.psync and l.psync instructions. 2014-07-20 20:26:09 +03:00
elfcpp Add tls support to gold aarch64 backend. 2014-09-17 14:24:10 -07:00
etc PR external/{16327,16328}: Remove etc/configure.texi and etc/standards.texi. 2014-06-27 11:33:25 +02:00
gas Bump bfd version. 2014-10-15 10:21:25 +02:00
gdb Push pruning old threads down to the target 2014-10-15 22:54:13 +01:00
gold Fix error from previous patch where tosize and tovalue were redefined 2014-09-30 16:06:50 -07:00
gprof Bump bfd version. 2014-10-15 10:21:25 +02:00
include Sync libiberty with upstream GCC. 2014-10-11 10:29:10 +01:00
intl merge from gcc 2010-09-27 21:01:18 +00:00
ld Bump bfd version. 2014-10-15 10:21:25 +02:00
libdecnumber PR c/59871 c/ * c-typeck.c (build_compound_expr): Warn even for right-hand operand of a comma expression. (emit_side_effect_warnings): Likewise. libdecnumber/ * decNumberLocal.h (UBFROMUS, UBFROMUI): Remove last argument. testsuite/ * gcc.dg/20020220-2.c: Adjust dg-warning message. * gcc.dg/pr59871.c: New test. 2014-05-08 10:18:28 -06:00
libiberty Sync libiberty with upstream GCC. 2014-10-11 10:29:10 +01:00
opcodes Bump bfd version. 2014-10-15 10:21:25 +02:00
readline readline/search.c: Remove useless parameter '0' for rl_message() 2014-09-22 09:52:06 -04:00
sim Shadow SIM's debug_printf function 2014-08-28 11:59:09 +01:00
texinfo * texinfo/texinfo.tex: Update to version 2009-03-28.05. 2009-04-21 12:36:46 +00:00
.cvsignore
.gitattributes Add a .gitattributes file for use with git-merge-changelog 2014-07-25 18:07:23 -04:00
.gitignore Sync the root .gitignore file with GCC's. 2013-01-11 15:17:35 +00:00
ChangeLog src-release.sh: configure using --target. 2014-10-15 09:50:53 +02:00
compile Update automake-provided files in the toplevel. 2009-08-22 11:48:33 +00:00
config-ml.in * config-ml.in: Don't handle arc-*-elf*. 2011-03-22 20:01:13 +00:00
config.guess * config.sub, config.guess: Import from upstream. 2014-05-01 21:49:01 +01:00
config.rpath Remove freebsd1 from libtool.m4 macros and config.rpath. 2011-02-13 21:00:14 +00:00
config.sub Import config.sub from upstream config repo 2014-07-29 07:04:52 -04:00
configure Add aarch64 to list of targets that support gold. 2014-10-03 14:48:14 -07:00
configure.ac Add aarch64 to list of targets that support gold. 2014-10-03 14:48:14 -07:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS 2013-01-07 Jeff Johnston <jjohnstn@redhat.com> 2013-01-07 21:39:26 +00:00
COPYING.NEWLIB 2013-10-01 Jeff Johnston <jjohnstn@redhat.com> 2013-10-01 18:14:04 +00:00
depcomp Update automake-provided files in the toplevel. 2009-08-22 11:48:33 +00:00
djunpack.bat * djunpack.bat: Use ".." quoting in Sed command, for the sake of 2009-03-27 13:37:09 +00:00
install-sh Update automake-provided files in the toplevel. 2009-08-22 11:48:33 +00:00
libtool.m4 * libtool.m4 (_LT_ENABLE_LOCK <ld -m flags>): Remove non-canonical 2013-09-20 09:51:25 +00:00
lt~obsolete.m4 Sync Libtool from GCC. 2010-01-09 21:11:44 +00:00
ltgcc.m4
ltmain.sh PR target/59788 2014-02-06 11:01:57 +01:00
ltoptions.m4 Sync Libtool from GCC. 2010-01-09 21:11:44 +00:00
ltsugar.m4
ltversion.m4 Sync Libtool from GCC. 2010-01-09 21:11:44 +00:00
MAINTAINERS MAINTAINERS: clarify policy with config/ (and other top level files) 2012-05-12 03:10:17 +00:00
Makefile.def PR sanitizer/56781 * Makefile.def: Set bootstrap=true; for host fixincludes. * configure.ac: Don't bootstrap host fixincludes unless --with-build-config=bootstrap-{a,ub}san. * Makefile.in: Regenerated. * configure: Regenerated. 2014-05-08 10:18:30 -06:00
Makefile.in PR sanitizer/56781 * Makefile.def: Set bootstrap=true; for host fixincludes. * configure.ac: Don't bootstrap host fixincludes unless --with-build-config=bootstrap-{a,ub}san. * Makefile.in: Regenerated. * configure: Regenerated. 2014-05-08 10:18:30 -06:00
Makefile.tpl PR bootstrap/58572 * Makefile.tpl (POSTSTAGE1_CXX_EXPORT): Use -isystem instead of -I for libstdc++-v3 includes if $(LEAN). * Makefile.in: Regenerated. 2014-05-08 10:18:29 -06:00
makefile.vms
missing Update automake-provided files in the toplevel. 2009-08-22 11:48:33 +00:00
mkdep
mkinstalldirs Update automake-provided files in the toplevel. 2009-08-22 11:48:33 +00:00
move-if-change Import move-if-change script from gnulib. 2011-02-12 15:47:02 +00:00
README
README-maintainer-mode Cleanups after the update to Autoconf 2.64, Automake 1.11. 2009-08-22 17:08:11 +00:00
setup.com 2009-09-01 Tristan Gingold <gingold@adacore.com> 2009-09-01 13:38:26 +00:00
src-release.sh src-release.sh: configure using --target. 2014-10-15 09:50:53 +02:00
symlink-tree
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		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.