| /* |
| * Copyright (c) 2002, Intel Corporation. All rights reserved. |
| * This file is licensed under the GPL license. For the full content |
| * of this license, see the COPYING file at the top level of this |
| * source tree. |
| |
| * Test that pthread_rwlock_unlock(pthread_rwlock_t *rwlock) |
| * |
| * pthread_rwlock_unlock() function shall release a lock held on the |
| * read-write lock object referenced by rwlock |
| * If this function is called to release a read lock from the read-write lock object |
| * and there are other read locks currently held on this read-write lock object, |
| * the read-write lock object remains in the read locked state. |
| * If this function releases the last read lock for this read-write lock object, |
| * the read-write lock object shall be put in the unlocked state with no owners. |
| * |
| * Steps: |
| * 1. Initialize a pthread_rwlock_t object 'rwlock' with pthread_rwlock_init() |
| * 2. Main thread read lock 'rwlock' |
| * 3. Create a child thread, the thread read lock 'rwlock', should not block |
| * 4. Child thread unlock 'rwlock', while the main thread still hold the read lock. |
| * 5. Child thread read lock 'rwlock' again, should succeed, then unlock again |
| * 6. Child thread write lock 'rwlock', should block |
| * 7. Main thread unlock the read lock, the 'rwlock' is in unlocked state |
| * 8. Child thread should get the lock for writing. |
| */ |
| #define _XOPEN_SOURCE 600 |
| #include <pthread.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include "posixtest.h" |
| |
| static pthread_rwlock_t rwlock; |
| static int thread_state; |
| |
| /* thread_state indicates child thread state: |
| 1: not in child thread yet; |
| 2: just enter child thread ; |
| 3: after 1st read lock |
| 4: after 2nd read lock and before write lock; |
| 5: just before child thread exit; |
| */ |
| |
| #define NOT_CREATED_THREAD 1 |
| #define ENTERED_THREAD 2 |
| #define PASSED_RLOCK1 3 |
| #define PASSED_RLOCK2 4 |
| #define EXITING_THREAD 5 |
| |
| static void *fn_rd(void *arg) |
| { |
| int rc = 0; |
| |
| thread_state = ENTERED_THREAD; |
| printf("thread: attempt 1st read lock\n"); |
| if (pthread_rwlock_rdlock(&rwlock) != 0) { |
| printf("thread: cannot get read lock\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| printf("thread: acquired read lock\n"); |
| printf("thread: unlock read lock\n"); |
| rc = pthread_rwlock_unlock(&rwlock); |
| if (rc != 0) { |
| printf |
| ("Test FAILED: thread: Error at pthread_rwlock_unlock(), Error Code=%d\n", |
| rc); |
| exit(PTS_FAIL); |
| } |
| |
| thread_state = PASSED_RLOCK1; |
| printf("thread: attempt 2nd read lock\n"); |
| if (pthread_rwlock_rdlock(&rwlock) != 0) { |
| printf("thread: cannot get read lock\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| printf("thread: acquired read lock\n"); |
| printf("thread: unlock read lock\n"); |
| rc = pthread_rwlock_unlock(&rwlock); |
| if (rc != 0) { |
| printf |
| ("Test FAILED: thread: Error at 2nd pthread_rwlock_unlock(), Error Code=%d\n", |
| rc); |
| exit(PTS_FAIL); |
| } |
| |
| thread_state = PASSED_RLOCK2; |
| /* The thread should block here */ |
| printf("thread: attempt write lock\n"); |
| if (pthread_rwlock_wrlock(&rwlock) != 0) { |
| printf("thread: cannot get write lock\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| printf("thread: acquired write lock\n"); |
| printf("thread: unlock write lock\n"); |
| rc = pthread_rwlock_unlock(&rwlock); |
| if (rc != 0) { |
| printf |
| ("Test FAILED: thread failed to release write lock, Error Code=%d\n", |
| rc); |
| exit(PTS_FAIL); |
| } |
| thread_state = EXITING_THREAD; |
| return NULL; |
| } |
| |
| int main(void) |
| { |
| int cnt = 0; |
| int rc = 0; |
| |
| pthread_t rd_thread; |
| |
| if (pthread_rwlock_init(&rwlock, NULL) != 0) { |
| printf("main: Error at pthread_rwlock_init()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| printf("main: attempt read lock\n"); |
| |
| /* This read lock should succeed */ |
| if (pthread_rwlock_rdlock(&rwlock) != 0) { |
| printf("main: Error at pthread_rwlock_rdlock()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| thread_state = NOT_CREATED_THREAD; |
| printf("main: create thread\n"); |
| if (pthread_create(&rd_thread, NULL, fn_rd, NULL) != 0) { |
| printf("main: Error at pthread_create()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| /* If the shared data is not altered by child after 3 seconds, |
| we regard it as blocked */ |
| cnt = 0; |
| do { |
| sleep(1); |
| } while (thread_state != PASSED_RLOCK2 && cnt++ < 3); |
| |
| if (thread_state == ENTERED_THREAD) { |
| printf("Thread should not block on first read lock\n"); |
| exit(PTS_UNRESOLVED); |
| } else if (thread_state == PASSED_RLOCK1) { |
| /* child thread blocked on second read lock */ |
| printf("thread should not block on second read lock\n"); |
| exit(PTS_UNRESOLVED); |
| } else if (thread_state != PASSED_RLOCK2) { |
| printf("Unexpected thread state: %d\n", thread_state); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| /* thread_state == 4, i.e. child thread blocks on write lock */ |
| printf("main: unlock read lock\n"); |
| rc = pthread_rwlock_unlock(&rwlock); |
| if (rc != 0) { |
| printf("Test FAILED: Main cannot release read lock\n"); |
| exit(PTS_FAIL); |
| } |
| |
| cnt = 0; |
| do { |
| sleep(1); |
| } while (thread_state != EXITING_THREAD && cnt++ < 3); |
| |
| if (thread_state != EXITING_THREAD) { |
| printf |
| ("Test FAILED: thread did not get write lock even when the lock has no owner\n"); |
| exit(PTS_FAIL); |
| } |
| |
| if (pthread_join(rd_thread, NULL) != 0) { |
| printf("Error at pthread_join()\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| if (pthread_rwlock_destroy(&rwlock) != 0) { |
| printf("Error at pthread_rwlock_destroy()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| printf("Test PASSED\n"); |
| return PTS_PASS; |
| } |