@@ -273,6 +273,7 @@ tests := \
tst-bsearch \
tst-bz20544 \
tst-canon-bz26341 \
+ tst-concurrent-quick_exit \
tst-concurrent-exit \
tst-cxa_atexit \
tst-environ \
@@ -28,6 +28,13 @@
__exit_funcs_lock is declared. */
bool __exit_funcs_done = false;
+/* The lock handles concurrent exit() and quick_exit(), even though the
+ C/POSIX standard states that calling exit() more than once is UB. The
+ recursive lock allows atexit() handlers or destructors to call exit()
+ itself. In this case, the handler list execution will resume at the
+ point of the current handler. */
+__libc_lock_define_initialized_recursive (static, __exit_lock)
+
/* Call all functions registered with `atexit' and `on_exit',
in the reverse of the order in which they were registered
perform stdio cleanup, and terminate program execution with STATUS. */
@@ -36,6 +43,9 @@ attribute_hidden
__run_exit_handlers (int status, struct exit_function_list **listp,
bool run_list_atexit, bool run_dtors)
{
+ /* The exit should never return, so there is no need to unlock it. */
+ __libc_lock_lock_recursive (__exit_lock);
+
/* First, call the TLS destructors. */
if (run_dtors)
call_function_static_weak (__call_tls_dtors);
@@ -132,17 +142,9 @@ __run_exit_handlers (int status, struct exit_function_list **listp,
}
-/* The lock handles concurrent exit(), even though the C/POSIX standard states
- that calling exit() more than once is UB. The recursive lock allows
- atexit() handlers or destructors to call exit() itself. In this case, the
- handler list execution will resume at the point of the current handler. */
-__libc_lock_define_initialized_recursive (static, __exit_lock)
-
void
exit (int status)
{
- /* The exit should never return, so there is no need to unlock it. */
- __libc_lock_lock_recursive (__exit_lock);
__run_exit_handlers (status, &__exit_funcs, true, true);
}
libc_hidden_def (exit)
new file mode 100644
@@ -0,0 +1,160 @@
+/* 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>
@@ -16,142 +16,7 @@
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>
+#define EXIT(__r) exit (__r)
+#define ATEXIT(__f) atexit (__f)
-#define MAX_atexit 32
-
-static pthread_barrier_t barrier;
-
-static void *
-tf (void *closure)
-{
- xpthread_barrier_wait (&barrier);
- exit (0);
-
- return NULL;
-}
-
-static const char expected[] = "00000000000000000000000003021121130211";
-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>
+#include "tst-concurrent-exit-skeleton.c"
new file mode 100644
@@ -0,0 +1,22 @@
+/* Check if 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/>. */
+
+#define EXIT(__r) quick_exit (__r)
+#define ATEXIT(__f) at_quick_exit (__f)
+
+#include "tst-concurrent-exit-skeleton.c"