/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. 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 <http://www.gnu.org/licenses/>. */ #include <errno.h> #include <pthread.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/mman.h> #include <sys/wait.h> static int do_test (void) { size_t ps = sysconf (_SC_PAGESIZE); char tmpfname[] = "/tmp/tst-rwlock12.XXXXXX"; char data[ps]; void *mem; int fd; pthread_mutex_t *m; pthread_mutexattr_t ma; pthread_rwlock_t *r; pthread_rwlockattr_t ra; pid_t pid; int status = 0; fd = mkstemp (tmpfname); if (fd == -1) { printf ("cannot open temporary file: %m\n"); return 1; } /* Make sure it is always removed. */ unlink (tmpfname); /* Create one page of data. */ memset (data, '\0', ps); /* Write the data to the file. */ if (write (fd, data, ps) != (ssize_t) ps) { puts ("short write"); return 1; } mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (mem == MAP_FAILED) { printf ("mmap failed: %m\n"); return 1; } r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t)) & ~(__alignof (pthread_rwlock_t) - 1)); /* The following assumes alignment for a mutex is at least as high as that for a rwlock. Which is true in our case. */ m = (pthread_mutex_t *) (r + 1); if (pthread_rwlockattr_init (&ra) != 0) { puts ("rwlockattr_init failed"); return 1; } if (pthread_rwlockattr_setpshared (&ra, PTHREAD_PROCESS_SHARED) != 0) { puts ("rwlockattr_setpshared failed"); return 1; } if (pthread_rwlock_init (r, &ra) != 0) { puts ("rwlock_init failed"); return 1; } if (pthread_mutexattr_init (&ma) != 0) { puts ("rwlockattr_init failed"); return 1; } if (pthread_mutexattr_setpshared (&ma, PTHREAD_PROCESS_SHARED) != 0) { puts ("mutexattr_setpshared failed"); return 1; } if (pthread_mutex_init (m, &ma) != 0) { puts ("mutex_init failed"); return 1; } /* Lock the mutex. */ if (pthread_mutex_lock (m) != 0) { puts ("mutex_lock failed"); return 1; } puts ("going to fork now"); pid = fork (); if (pid == -1) { puts ("fork failed"); return 1; } else if (pid == 0) { /* Lock the mutex. */ if (pthread_mutex_lock (m) != 0) { puts ("child: mutex_lock failed"); return 1; } /* Try to get the rwlock. */ if (pthread_rwlock_trywrlock (r) == 0) { puts ("rwlock_trywrlock succeeded"); return 1; } /* Try again. */ struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 }; int e = pthread_rwlock_timedwrlock (r, &ts); if (e == 0) { puts ("rwlock_timedwrlock succeeded"); return 1; } if (e != ETIMEDOUT) { puts ("rwlock_timedwrlock didn't return ETIMEDOUT"); status = 1; } if (pthread_rwlock_tryrdlock (r) == 0) { puts ("rwlock_tryrdlock succeeded"); return 1; } e = pthread_rwlock_timedrdlock (r, &ts); if (e == 0) { puts ("rwlock_timedrdlock succeeded"); return 1; } if (e != ETIMEDOUT) { puts ("rwlock_timedrdlock didn't return ETIMEDOUT"); status = 1; } } else { /* Lock the rwlock for writing. */ if (pthread_rwlock_wrlock (r) != 0) { puts ("rwlock_wrlock failed"); kill (pid, SIGTERM); return 1; } /* Allow the child to run. */ if (pthread_mutex_unlock (m) != 0) { puts ("mutex_unlock failed"); kill (pid, SIGTERM); return 1; } /* Just wait for the child. */ if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid) { puts ("waitpid failed"); kill (pid, SIGTERM); return 1; } } return status; } #define TEST_FUNCTION do_test () #include "../test-skeleton.c"