| /* |
| * 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 pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock) |
| * |
| * The function shall apply a write lock like the pthread_rwlock_wrlock(), with the exception |
| * that the function shall fail if any thread currently holds rwlock(for reading and writing). |
| * |
| * Steps: |
| * 1. Initialize a pthread_rwlock_t object 'rwlock' with pthread_rwlock_init() |
| * 2. Main thread lock 'rwlock' for reading with pthread_rwlock_rdlock() |
| * 3. Create a child thread, the thread locks 'rwlock' for writing, using |
| * pthread_rwlock_trywrlock(), should get EBUSY |
| * 4. Main thread unlocks 'rwlock' |
| * 5. Main thread locks 'rwlock' for writing, using pthread_rwlock_trywrlock(), |
| * should get the lock successfully |
| * 6. Create child thread to lock 'rwlock' for writing, with pthread_rwlock_trywrlock(), |
| * should get EBUSY |
| * 7. Main thread unlock 'rwlock' |
| */ |
| #define _XOPEN_SOURCE 600 |
| #include <pthread.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include "posixtest.h" |
| |
| static pthread_rwlock_t rwlock; |
| static int thread_state; |
| static int get_ebusy; |
| |
| /* thread_state indicates child thread state: |
| 1: not in child thread yet; |
| 2: just enter child thread ; |
| 3: just before child thread exit; |
| */ |
| |
| #define NOT_CREATED_THREAD 1 |
| #define ENTERED_THREAD 2 |
| #define EXITING_THREAD 3 |
| |
| static void *fn_wr(void *arg) |
| { |
| thread_state = ENTERED_THREAD; |
| int rc; |
| |
| printf("thread: attempt pthread_rwlock_trywrlock()\n"); |
| rc = pthread_rwlock_trywrlock(&rwlock); |
| if (rc != EBUSY) { |
| printf("Test FAILED: thread: Expected EBUSY, got %d\n", rc); |
| exit(PTS_FAIL); |
| } |
| get_ebusy = 1; |
| printf("thread: correctly got EBUSY\n"); |
| thread_state = EXITING_THREAD; |
| pthread_exit(0); |
| return NULL; |
| } |
| |
| int main(void) |
| { |
| int cnt = 0; |
| int rc = 0; |
| pthread_t thread1, thread2; |
| |
| get_ebusy = 0; |
| |
| if (pthread_rwlock_init(&rwlock, NULL) != 0) { |
| printf("main: Error at pthread_rwlock_init()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| printf("main: attempt read lock\n"); |
| /* We have no lock, this read lock should succeed */ |
| if (pthread_rwlock_rdlock(&rwlock) != 0) { |
| printf("main: Error at pthread_rwlock_rdlock()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| printf("main: acquired read lock\n"); |
| thread_state = NOT_CREATED_THREAD; |
| printf("main: create thread1\n"); |
| if (pthread_create(&thread1, NULL, fn_wr, NULL) != 0) { |
| printf("Error creating thread1\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| /* If the shared data is not altered by child after 3 seconds, |
| we regard it as blocked */ |
| /* We do no expect thread1 to block */ |
| cnt = 0; |
| do { |
| sleep(1); |
| } while (thread_state != EXITING_THREAD && cnt++ < 3); |
| |
| if (thread_state == ENTERED_THREAD) { |
| /* the child thread blocked */ |
| printf |
| ("Test FAILED: thread1 should not block on pthread_rwlock_trywrlock()\n"); |
| exit(PTS_FAIL); |
| } else if (thread_state != EXITING_THREAD) { |
| printf("Unexpected thread state for thread1: %d\n", |
| thread_state); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| if (get_ebusy != 1) { |
| printf("Test FAILED: thread1 should get EBUSY\n"); |
| exit(PTS_FAIL); |
| } |
| |
| printf("main: unlock read lock\n"); |
| if (pthread_rwlock_unlock(&rwlock) != 0) { |
| printf("main: Error releasing read lock\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| if (pthread_join(thread1, NULL) != 0) { |
| printf("main: Error joining thread1\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| printf("main: attempt pthread_rwlock_trywrlock()\n"); |
| /* Should get the write lock */ |
| rc = pthread_rwlock_trywrlock(&rwlock); |
| if (rc != 0) { |
| printf |
| ("Test FAILED: main failed at pthread_rwlock_trywrlock(), error code: %d\n", |
| rc); |
| return PTS_FAIL; |
| } |
| |
| printf("main: acquired write lock\n"); |
| |
| get_ebusy = 0; |
| thread_state = NOT_CREATED_THREAD; |
| cnt = 0; |
| printf("main: create thread2\n"); |
| if (pthread_create(&thread2, NULL, fn_wr, NULL) != 0) { |
| printf("main: Error creating thread2\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| /* We do not expect thread2 to block */ |
| do { |
| sleep(1); |
| } while (thread_state != EXITING_THREAD && cnt++ < 3); |
| |
| if (thread_state == ENTERED_THREAD) { |
| printf |
| ("Test FAILED: thread2 should not block on pthread_rwlock_trywrlock()\n"); |
| exit(PTS_FAIL); |
| } else if (thread_state != EXITING_THREAD) { |
| printf("Unexpected thread state: %d\n", thread_state); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| if (get_ebusy != 1) { |
| printf("Test FAILED: thread2 should get EBUSY\n"); |
| exit(PTS_FAIL); |
| } |
| |
| printf("main: unlock write lock\n"); |
| thread_state = 1; |
| if (pthread_rwlock_unlock(&rwlock) != 0) { |
| printf("main: Error at 2nd pthread_rwlock_unlock()\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| if (pthread_join(thread2, NULL) != 0) { |
| printf("main: Error at 2cn pthread_join()\n"); |
| exit(PTS_UNRESOLVED); |
| } |
| |
| if (pthread_rwlock_destroy(&rwlock) != 0) { |
| printf("Error at pthread_rwlockattr_destroy()\n"); |
| return PTS_UNRESOLVED; |
| } |
| |
| printf("Test PASSED\n"); |
| return PTS_PASS; |
| } |