Calling pthread_mutex_lock() twice with the same mutex in the same thread without unlocking it first is invalid. The intention behind this pattern was to wait for the recv_fn() thread to be ready. Use the pthread barrier instead. It is more straightforward and correct. Fixes: https://github.com/axboe/liburing/issues/855 Reported-by: Barnabás Pőcze <pobrn@xxxxxxxxxxxxxx> Signed-off-by: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx> --- test/recv-msgall.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/test/recv-msgall.c b/test/recv-msgall.c index f809834b2e427fc5..d1fcdb0d510423e7 100644 --- a/test/recv-msgall.c +++ b/test/recv-msgall.c @@ -19,7 +19,7 @@ #define HOST "127.0.0.1" static __be16 bind_port; struct recv_data { - pthread_mutex_t mutex; + pthread_barrier_t barrier; int use_recvmsg; struct msghdr msg; }; @@ -122,11 +122,11 @@ static void *recv_fn(void *data) ret = t_create_ring_params(1, &ring, &p); if (ret == T_SETUP_SKIP) { - pthread_mutex_unlock(&rd->mutex); + pthread_barrier_wait(&rd->barrier); ret = 0; goto err; } else if (ret < 0) { - pthread_mutex_unlock(&rd->mutex); + pthread_barrier_wait(&rd->barrier); goto err; } @@ -135,7 +135,7 @@ static void *recv_fn(void *data) fprintf(stderr, "recv_prep failed: %d\n", ret); goto err; } - pthread_mutex_unlock(&rd->mutex); + pthread_barrier_wait(&rd->barrier); ret = do_recv(&ring); close(sock); io_uring_queue_exit(&ring); @@ -219,28 +219,24 @@ err: static int test(int use_recvmsg) { - pthread_mutexattr_t attr; pthread_t recv_thread; struct recv_data rd; int ret; void *retval; - pthread_mutexattr_init(&attr); - pthread_mutexattr_setpshared(&attr, 1); - pthread_mutex_init(&rd.mutex, &attr); - pthread_mutex_lock(&rd.mutex); + pthread_barrier_init(&rd.barrier, NULL, 2); rd.use_recvmsg = use_recvmsg; ret = pthread_create(&recv_thread, NULL, recv_fn, &rd); if (ret) { fprintf(stderr, "Thread create failed: %d\n", ret); - pthread_mutex_unlock(&rd.mutex); return 1; } - pthread_mutex_lock(&rd.mutex); + pthread_barrier_wait(&rd.barrier); do_send(); pthread_join(recv_thread, &retval); + pthread_barrier_destroy(&rd.barrier); return (intptr_t)retval; } -- Ammar Faizi
