mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-21 01:12:26 +08:00
c6af8a9a3c
As for exit, also allows concurrent quick_exit to avoid race conditions when it is called concurrently. Since it uses the same internal function as exit, the __exit_lock lock is moved to __run_exit_handlers. It also solved a potential concurrent when calling exit and quick_exit concurrently. The test case 'expected' is expanded to a value larger than the minimum required by C/POSIX (32 entries) so at_quick_exit() will require libc to allocate a new block. This makes the test mre likely to trigger concurrent issues (through free() at __run_exit_handlers) if quick_exit() interacts with the at_quick_exit list concurrently. This is also the latest interpretation of the Austin Ticket [1]. Checked on x86_64-linux-gnu. [1] https://austingroupbugs.net/view.php?id=1845 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
161 lines
3.8 KiB
C
161 lines
3.8 KiB
C
/* Check if exit/quick_exit can be called concurrently by multiple threads.
|
|
Copyright (C) 2024 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 <array_length.h>
|
|
#include <stdlib.h>
|
|
#include <support/check.h>
|
|
#include <support/xthread.h>
|
|
#include <stdio.h>
|
|
#include <support/xunistd.h>
|
|
#include <string.h>
|
|
|
|
/* A value larger than the minimum required by C/POSIX (32), to trigger a
|
|
new block memory allocation. */
|
|
#define MAX_atexit 64
|
|
|
|
static pthread_barrier_t barrier;
|
|
|
|
static void *
|
|
tf (void *closure)
|
|
{
|
|
xpthread_barrier_wait (&barrier);
|
|
EXIT (0);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static const char expected[] = "00000000000000000000000000000000000"
|
|
"00000000000000000000003021121130211";
|
|
static char crumbs[sizeof (expected)];
|
|
static int next_slot = 0;
|
|
|
|
static void
|
|
exit_with_flush (int code)
|
|
{
|
|
fflush (stdout);
|
|
/* glibc allows recursive EXIT, the ATEXIT handlers execution will be
|
|
resumed from the where the previous EXIT was interrupted. */
|
|
EXIT (code);
|
|
}
|
|
|
|
/* Take some time, so another thread potentially issue EXIT. */
|
|
#define SETUP_NANOSLEEP \
|
|
if (nanosleep (&(struct timespec) { .tv_sec = 0, .tv_nsec = 1000L }, \
|
|
NULL) != 0) \
|
|
FAIL_EXIT1 ("nanosleep: %m")
|
|
|
|
static void
|
|
fn0 (void)
|
|
{
|
|
crumbs[next_slot++] = '0';
|
|
SETUP_NANOSLEEP;
|
|
}
|
|
|
|
static void
|
|
fn1 (void)
|
|
{
|
|
crumbs[next_slot++] = '1';
|
|
SETUP_NANOSLEEP;
|
|
}
|
|
|
|
static void
|
|
fn2 (void)
|
|
{
|
|
crumbs[next_slot++] = '2';
|
|
ATEXIT (fn1);
|
|
SETUP_NANOSLEEP;
|
|
}
|
|
|
|
static void
|
|
fn3 (void)
|
|
{
|
|
crumbs[next_slot++] = '3';
|
|
ATEXIT (fn2);
|
|
ATEXIT (fn0);
|
|
SETUP_NANOSLEEP;
|
|
}
|
|
|
|
static void
|
|
fn_final (void)
|
|
{
|
|
TEST_COMPARE_STRING (crumbs, expected);
|
|
exit_with_flush (0);
|
|
}
|
|
|
|
_Noreturn static void
|
|
child (void)
|
|
{
|
|
enum { nthreads = 8 };
|
|
|
|
xpthread_barrier_init (&barrier, NULL, nthreads + 1);
|
|
|
|
pthread_t thr[nthreads];
|
|
for (int i = 0; i < nthreads; i++)
|
|
thr[i] = xpthread_create (NULL, tf, NULL);
|
|
|
|
xpthread_barrier_wait (&barrier);
|
|
|
|
for (int i = 0; i < nthreads; i++)
|
|
{
|
|
pthread_join (thr[i], NULL);
|
|
/* It should not be reached, it means that thread did not exit for
|
|
some reason. */
|
|
support_record_failure ();
|
|
}
|
|
|
|
EXIT (2);
|
|
}
|
|
|
|
static int
|
|
do_test (void)
|
|
{
|
|
/* Register a large number of handler that will trigger a heap allocation
|
|
for the handle state. On EXIT, each block will be freed after the
|
|
handle is processed. */
|
|
int slots_remaining = MAX_atexit;
|
|
|
|
/* Register this first so it can verify expected order of the rest. */
|
|
ATEXIT (fn_final); --slots_remaining;
|
|
|
|
TEST_VERIFY_EXIT (ATEXIT (fn1) == 0); --slots_remaining;
|
|
TEST_VERIFY_EXIT (ATEXIT (fn3) == 0); --slots_remaining;
|
|
TEST_VERIFY_EXIT (ATEXIT (fn1) == 0); --slots_remaining;
|
|
TEST_VERIFY_EXIT (ATEXIT (fn2) == 0); --slots_remaining;
|
|
TEST_VERIFY_EXIT (ATEXIT (fn1) == 0); --slots_remaining;
|
|
TEST_VERIFY_EXIT (ATEXIT (fn3) == 0); --slots_remaining;
|
|
|
|
while (slots_remaining > 0)
|
|
{
|
|
TEST_VERIFY_EXIT (ATEXIT (fn0) == 0); --slots_remaining;
|
|
}
|
|
|
|
pid_t pid = xfork ();
|
|
if (pid != 0)
|
|
{
|
|
int status;
|
|
xwaitpid (pid, &status, 0);
|
|
TEST_VERIFY (WIFEXITED (status));
|
|
}
|
|
else
|
|
child ();
|
|
|
|
return 0;
|
|
}
|
|
|
|
#include <support/test-driver.c>
|