/* * Copyright (c) 2001-2004 Jakub Jermar * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #define THREADS 4 static atomic_t thread_count; static rwlock_t rwlock; static bool sh_quiet; static void reader(void *arg) { thread_detach(THREAD); if (!sh_quiet) printf("cpu%u, tid %" PRIu64 ": trying to lock rwlock for reading....\n", CPU->id, THREAD->tid); rwlock_read_lock(&rwlock); rwlock_read_unlock(&rwlock); if (!sh_quiet) { printf("cpu%u, tid %" PRIu64 ": success\n", CPU->id, THREAD->tid); printf("cpu%u, tid %" PRIu64 ": trying to lock rwlock for writing....\n", CPU->id, THREAD->tid); } rwlock_write_lock(&rwlock); rwlock_write_unlock(&rwlock); if (!sh_quiet) printf("cpu%u, tid %" PRIu64 ": success\n", CPU->id, THREAD->tid); atomic_dec(&thread_count); } char * test_rwlock3(bool quiet) { int i; thread_t *thrd; sh_quiet = quiet; atomic_set(&thread_count, THREADS); rwlock_initialize(&rwlock); rwlock_write_lock(&rwlock); for (i = 0; i < THREADS; i++) { thrd = thread_create(reader, NULL, TASK, 0, "reader", false); if (thrd) thread_ready(thrd); else if (!quiet) printf("Could not create reader %d\n", i); } thread_sleep(1); rwlock_write_unlock(&rwlock); while (atomic_get(&thread_count) > 0) { if (!quiet) printf("Threads left: %ld\n", atomic_get(&thread_count)); thread_sleep(1); } return NULL; }