diff options
| -rw-r--r-- | stdlib/Makefile | 1 | ||||
| -rw-r--r-- | stdlib/exit.c | 18 | ||||
| -rw-r--r-- | stdlib/tst-concurrent-exit-skeleton.c | 160 | ||||
| -rw-r--r-- | stdlib/tst-concurrent-exit.c | 141 | ||||
| -rw-r--r-- | stdlib/tst-concurrent-quick_exit.c | 22 |
5 files changed, 196 insertions, 146 deletions
diff --git a/stdlib/Makefile b/stdlib/Makefile index f659c38..043a452 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -274,6 +274,7 @@ tests := \ tst-bz20544 \ tst-canon-bz26341 \ tst-concurrent-exit \ + tst-concurrent-quick_exit \ tst-cxa_atexit \ tst-environ \ tst-getrandom \ diff --git a/stdlib/exit.c b/stdlib/exit.c index bbaf138..8d7e2e5 100644 --- a/stdlib/exit.c +++ b/stdlib/exit.c @@ -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) diff --git a/stdlib/tst-concurrent-exit-skeleton.c b/stdlib/tst-concurrent-exit-skeleton.c new file mode 100644 index 0000000..cfd5140 --- /dev/null +++ b/stdlib/tst-concurrent-exit-skeleton.c @@ -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> diff --git a/stdlib/tst-concurrent-exit.c b/stdlib/tst-concurrent-exit.c index 1141130..421c39d 100644 --- a/stdlib/tst-concurrent-exit.c +++ b/stdlib/tst-concurrent-exit.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" diff --git a/stdlib/tst-concurrent-quick_exit.c b/stdlib/tst-concurrent-quick_exit.c new file mode 100644 index 0000000..3f32166 --- /dev/null +++ b/stdlib/tst-concurrent-quick_exit.c @@ -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" |