| 1 | /* Test that pthread_cancel succeeds during thread exit. |
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| 2 | Copyright (C) 2021-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | /* This test tries to trigger an internal race condition in |
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| 20 | pthread_cancel, where the cancellation signal is sent after the |
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| 21 | thread has begun the cancellation process. This can result in a |
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| 22 | spurious ESRCH error. For the original bug 12889, the window is |
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| 23 | quite small, so the bug was not reproduced in every run. */ |
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| 24 | |
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| 25 | #include <stdbool.h> |
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| 26 | #include <stddef.h> |
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| 27 | #include <support/check.h> |
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| 28 | #include <support/xthread.h> |
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| 29 | #include <support/xunistd.h> |
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| 30 | #include <sys/select.h> |
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| 31 | #include <unistd.h> |
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| 32 | |
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| 33 | /* Set to true by timeout_thread_function when the test should |
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| 34 | terminate. */ |
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| 35 | static bool timeout; |
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| 36 | |
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| 37 | static void * |
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| 38 | timeout_thread_function (void *unused) |
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| 39 | { |
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| 40 | usleep (useconds: 5 * 1000 * 1000); |
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| 41 | __atomic_store_n (&timeout, true, __ATOMIC_RELAXED); |
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| 42 | return NULL; |
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| 43 | } |
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| 44 | |
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| 45 | /* Used for blocking the select function below. */ |
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| 46 | static int pipe_fds[2]; |
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| 47 | |
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| 48 | static void * |
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| 49 | canceled_thread_function (void *unused) |
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| 50 | { |
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| 51 | while (true) |
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| 52 | { |
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| 53 | fd_set rfs; |
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| 54 | fd_set wfs; |
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| 55 | fd_set efs; |
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| 56 | FD_ZERO (&rfs); |
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| 57 | FD_ZERO (&wfs); |
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| 58 | FD_ZERO (&efs); |
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| 59 | FD_SET (pipe_fds[0], &rfs); |
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| 60 | |
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| 61 | /* If the cancellation request is recognized early, the thread |
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| 62 | begins exiting while the cancellation signal arrives. */ |
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| 63 | select (FD_SETSIZE, readfds: &rfs, writefds: &wfs, exceptfds: &efs, NULL); |
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| 64 | } |
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| 65 | return NULL; |
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| 66 | } |
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| 67 | |
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| 68 | static int |
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| 69 | do_test (void) |
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| 70 | { |
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| 71 | xpipe (pipe_fds); |
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| 72 | pthread_t thr_timeout = xpthread_create (NULL, thread_func: timeout_thread_function, NULL); |
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| 73 | |
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| 74 | while (!__atomic_load_n (&timeout, __ATOMIC_RELAXED)) |
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| 75 | { |
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| 76 | pthread_t thr = xpthread_create (NULL, thread_func: canceled_thread_function, NULL); |
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| 77 | xpthread_cancel (thr); |
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| 78 | TEST_VERIFY (xpthread_join (thr) == PTHREAD_CANCELED); |
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| 79 | } |
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| 80 | |
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| 81 | xpthread_join (thr: thr_timeout); |
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| 82 | xclose (pipe_fds[0]); |
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| 83 | xclose (pipe_fds[1]); |
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| 84 | return 0; |
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| 85 | } |
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| 86 | |
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| 87 | #include <support/test-driver.c> |
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| 88 | |
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