mirror of
https://sourceware.org/git/glibc.git
synced 2025-11-03 20:53:13 +03:00
81 lines
3.0 KiB
C
81 lines
3.0 KiB
C
/* Out-of-line notification function for the GSCOPE locking mechanism.
|
|
Copyright (C) 2007-2025 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <nptl/descr.h>
|
|
#include <futex-internal.h>
|
|
#include <ldsodefs.h>
|
|
#include <list.h>
|
|
#include <lowlevellock.h>
|
|
|
|
void
|
|
__thread_gscope_wait (void)
|
|
{
|
|
lll_lock (GL (dl_stack_cache_lock), LLL_PRIVATE);
|
|
|
|
struct pthread *self = THREAD_SELF;
|
|
|
|
/* Iterate over the list with system-allocated threads first. */
|
|
list_t *runp;
|
|
list_for_each (runp, &GL (dl_stack_used))
|
|
{
|
|
struct pthread *t = list_entry (runp, struct pthread, list);
|
|
if (t == self || t->header.gscope_flag == THREAD_GSCOPE_FLAG_UNUSED)
|
|
continue;
|
|
|
|
int *const gscope_flagp = &t->header.gscope_flag;
|
|
|
|
/* We have to wait until this thread is done with the global
|
|
scope. First tell the thread that we are waiting and
|
|
possibly have to be woken. */
|
|
if (atomic_compare_and_exchange_bool_acq (gscope_flagp,
|
|
THREAD_GSCOPE_FLAG_WAIT,
|
|
THREAD_GSCOPE_FLAG_USED))
|
|
continue;
|
|
|
|
do
|
|
futex_wait_simple ((unsigned int *) gscope_flagp,
|
|
THREAD_GSCOPE_FLAG_WAIT, FUTEX_PRIVATE);
|
|
while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT);
|
|
}
|
|
|
|
/* Now the list with threads using user-allocated stacks. */
|
|
list_for_each (runp, &GL (dl_stack_user))
|
|
{
|
|
struct pthread *t = list_entry (runp, struct pthread, list);
|
|
if (t == self || t->header.gscope_flag == THREAD_GSCOPE_FLAG_UNUSED)
|
|
continue;
|
|
|
|
int *const gscope_flagp = &t->header.gscope_flag;
|
|
|
|
/* We have to wait until this thread is done with the global
|
|
scope. First tell the thread that we are waiting and
|
|
possibly have to be woken. */
|
|
if (atomic_compare_and_exchange_bool_acq (gscope_flagp,
|
|
THREAD_GSCOPE_FLAG_WAIT,
|
|
THREAD_GSCOPE_FLAG_USED))
|
|
continue;
|
|
|
|
do
|
|
futex_wait_simple ((unsigned int *) gscope_flagp,
|
|
THREAD_GSCOPE_FLAG_WAIT, FUTEX_PRIVATE);
|
|
while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT);
|
|
}
|
|
|
|
lll_unlock (GL (dl_stack_cache_lock), LLL_PRIVATE);
|
|
}
|