| 1 | /* Helper for exit/dlclose race test (Bug 22180). |
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| 2 | Copyright (C) 2017-2022 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 | #include <stdio.h> |
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| 20 | #include <stdbool.h> |
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| 21 | #include <stdlib.h> |
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| 22 | #include <semaphore.h> |
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| 23 | #include <unistd.h> |
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| 24 | #include <support/check.h> |
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| 25 | #include <support/xthread.h> |
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| 26 | |
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| 27 | /* Semaphore defined in executable to ensure we have a happens-before |
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| 28 | between the first function starting and exit being called. */ |
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| 29 | extern sem_t order1; |
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| 30 | |
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| 31 | /* Semaphore defined in executable to ensure we have a happens-before |
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| 32 | between the second function starting and the first function returning. */ |
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| 33 | extern sem_t order2; |
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| 34 | |
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| 35 | /* glibc function for registering DSO-specific exit functions. */ |
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| 36 | extern int __cxa_atexit (void (*func) (void *), void *arg, void *dso_handle); |
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| 37 | |
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| 38 | /* Hidden compiler handle to this shared object. */ |
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| 39 | extern void *__dso_handle __attribute__ ((__weak__)); |
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| 40 | |
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| 41 | static void |
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| 42 | first (void *start) |
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| 43 | { |
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| 44 | /* Let the exiting thread run. */ |
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| 45 | sem_post (sem: &order1); |
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| 46 | |
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| 47 | /* Wait for exiting thread to finish. */ |
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| 48 | sem_wait (sem: &order2); |
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| 49 | |
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| 50 | printf (format: "first\n" ); |
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| 51 | } |
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| 52 | |
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| 53 | static void |
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| 54 | second (void *start) |
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| 55 | { |
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| 56 | /* We may be called from different threads. |
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| 57 | This lock protects called. */ |
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| 58 | static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER; |
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| 59 | static bool called = false; |
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| 60 | |
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| 61 | xpthread_mutex_lock (mutex: &mtx); |
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| 62 | if (called) |
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| 63 | FAIL_EXIT1 ("second called twice!" ); |
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| 64 | |
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| 65 | called = true; |
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| 66 | xpthread_mutex_unlock (mutex: &mtx); |
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| 67 | |
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| 68 | printf (format: "second\n" ); |
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| 69 | } |
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| 70 | |
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| 71 | |
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| 72 | __attribute__ ((constructor)) static void |
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| 73 | constructor (void) |
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| 74 | { |
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| 75 | sem_init (sem: &order1, pshared: 0, value: 0); |
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| 76 | sem_init (sem: &order2, pshared: 0, value: 0); |
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| 77 | __cxa_atexit (func: second, NULL, dso_handle: __dso_handle); |
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| 78 | __cxa_atexit (func: first, NULL, dso_handle: __dso_handle); |
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| 79 | } |
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| 80 | |
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