/* 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 <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/file.h> #include <sys/mman.h> #include <sys/wait.h> static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; static pthread_mutex_t lock2 = PTHREAD_MUTEX_INITIALIZER; static int fd; static void * tf (void *arg) { struct flock fl = { .l_type = F_WRLCK, .l_start = 0, .l_whence = SEEK_SET, .l_len = 10 }; if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLKW, &fl)) != 0) { puts ("fourth fcntl failed"); exit (1); } pthread_mutex_unlock (&lock); pthread_mutex_lock (&lock2); return NULL; } static int do_test (void) { char tmp[] = "/tmp/tst-flock2-XXXXXX"; fd = mkstemp (tmp); if (fd == -1) { puts ("mkstemp failed"); return 1; } unlink (tmp); int i; for (i = 0; i < 20; ++i) write (fd, "foobar xyzzy", 12); pthread_barrier_t *b; b = mmap (NULL, sizeof (pthread_barrier_t), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); if (b == MAP_FAILED) { puts ("mmap failed"); return 1; } pthread_barrierattr_t ba; if (pthread_barrierattr_init (&ba) != 0) { puts ("barrierattr_init failed"); return 1; } if (pthread_barrierattr_setpshared (&ba, PTHREAD_PROCESS_SHARED) != 0) { puts ("barrierattr_setpshared failed"); return 1; } if (pthread_barrier_init (b, &ba, 2) != 0) { puts ("barrier_init failed"); return 1; } if (pthread_barrierattr_destroy (&ba) != 0) { puts ("barrierattr_destroy failed"); return 1; } struct flock fl = { .l_type = F_WRLCK, .l_start = 0, .l_whence = SEEK_SET, .l_len = 10 }; if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLKW, &fl)) != 0) { puts ("first fcntl failed"); return 1; } pid_t pid = fork (); if (pid == -1) { puts ("fork failed"); return 1; } if (pid == 0) { /* Make sure the child does not stay around indefinitely. */ alarm (10); /* Try to get the lock. */ if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLK, &fl)) == 0) { puts ("child: second flock succeeded"); return 1; } } pthread_barrier_wait (b); if (pid != 0) { fl.l_type = F_UNLCK; if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLKW, &fl)) != 0) { puts ("third fcntl failed"); return 1; } } pthread_barrier_wait (b); pthread_t th; if (pid == 0) { if (pthread_mutex_lock (&lock) != 0) { puts ("1st locking of lock failed"); return 1; } if (pthread_mutex_lock (&lock2) != 0) { puts ("1st locking of lock2 failed"); return 1; } if (pthread_create (&th, NULL, tf, NULL) != 0) { puts ("pthread_create failed"); return 1; } if (pthread_mutex_lock (&lock) != 0) { puts ("2nd locking of lock failed"); return 1; } puts ("child locked file"); } pthread_barrier_wait (b); if (pid != 0) { fl.l_type = F_WRLCK; if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLK, &fl)) == 0) { puts ("fifth fcntl succeeded"); return 1; } puts ("file locked by child"); } pthread_barrier_wait (b); if (pid == 0) { if (pthread_mutex_unlock (&lock2) != 0) { puts ("unlock of lock2 failed"); return 1; } if (pthread_join (th, NULL) != 0) { puts ("join failed"); return 1; } puts ("child's thread terminated"); } pthread_barrier_wait (b); if (pid != 0) { fl.l_type = F_WRLCK; if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLK, &fl)) == 0) { puts ("fifth fcntl succeeded"); return 1; } puts ("file still locked"); } pthread_barrier_wait (b); if (pid == 0) { _exit (0); } int status; if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid) { puts ("waitpid failed"); return 1; } puts ("child terminated"); if (TEMP_FAILURE_RETRY (fcntl (fd, F_SETLKW, &fl)) != 0) { puts ("sixth fcntl failed"); return 1; } return status; } #define TEST_FUNCTION do_test () #include "../test-skeleton.c"