Re: [LTP] [PATCH v4 2/2] open_posix_testsuite/../mq_timedsend/12-1: fix race

chrubis
2013-08-13T15:13:56Z

> /*
> * This handler is just used to catch the signal and stop sleep (so the
> @@ -59,12 +59,10 @@ int errno_eintr;
> */
> void justreturn_handler(int signo)
> {
> - /* Indicate that the signal handler was called */
> - in_handler = 1;
> - return;
> + in_handler++;
> }
>
> -void *a_thread_func()
> +void *a_thread_func(void *arg)
> {
> int i, ret;
> struct sigaction act;
> @@ -86,101 +84,111 @@ void *a_thread_func()
> attr.mq_maxmsg = MAXMSG;
> attr.mq_msgsize = BUFFER;
> gqueue = mq_open(gqname, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR, &attr);
> - if (gqueue == (mqd_t) - 1) {
> - perror("mq_open() did not return success");
> - pthread_exit((void *)PTS_UNRESOLVED);
> - return NULL;
> - }
> + if (gqueue == (mqd_t) -1)
> + error_and_exit(errno, "mq_open");
>
> - /* mq_timedsend will block for 10 seconds when it waits */
> - ts.tv_sec = time(NULL) + 10;
> + /* mq_timedsend will block for TIMEOUT seconds when it waits */
> + ts.tv_sec = time(NULL) + TIMEOUT;
> ts.tv_nsec = 0;
>
> - /* Tell main it can go ahead and start sending SIGUSR1 signal */
> - sem = INMAIN;
> + /* main can now start sending SIGUSR1 signal */
> + ret = pthread_barrier_wait(&barrier);
> + if (ret != 0 && ret != PTHREAD_BARRIER_SERIAL_THREAD)
> + error_and_exit(ret, "pthread_barrier_wait start");
>
> for (i = 0; i < MAXMSG + 1; i++) {
> ret = mq_timedsend(gqueue, msgptr, strlen(msgptr), 1, &ts);
> - if (ret != -1)
> - continue;
> -
> - if (errno == EINTR) {
> - if (mq_unlink(gqname) != 0) {
> - perror("mq_unlink() did not return success");
> - pthread_exit((void *)PTS_UNRESOLVED);
> - return NULL;
> - }
> - printf("thread: mq_timedsend interrupted by signal"
> - " and correctly set errno to EINTR\n");
> - errno_eintr = 1;
> - pthread_exit((void *)PTS_PASS);
> - return NULL;
> - } else {
> - printf("mq_timedsend not interrupted by signal or"
> - " set errno to incorrect code: %d\n", errno);
> - pthread_exit((void *)PTS_FAIL);
> - return NULL;
> + if (ret == -1) {
> + mq_timedsend_errno = errno;
> + break;
> }
> }
>
> - /* Tell main that it the thread did not block like it should have */
> - sem = INTHREAD;
> + if (mq_unlink(gqname) != 0)
> + error_and_exit(errno, "mq_unlink");
> +
> + switch (mq_timedsend_errno) {
> + case -1:
> + mq_timedsend_errno = 0;
> + printf("Error: mq_timedsend wasn't interrupted\n");
> + break;
> + case EINTR:
> + printf("thread: mq_timedsend interrupted by signal"
> + " and correctly set errno to EINTR\n");
> + break;
> + default:
> + printf("mq_timedsend not interrupted by signal or"
> + " set errno to incorrect code: %d\n",
> + mq_timedsend_errno);
> + break;
> + }
> +
> + /* wait until main stops sending signals */
> + ret = pthread_barrier_wait(&barrier);
> + if (ret != 0 && ret != PTHREAD_BARRIER_SERIAL_THREAD)
> + error_and_exit(ret, "pthread_barrier_wait end");
>
> - perror("Error: thread never blocked\n");
> - pthread_exit((void *)PTS_FAIL);
> - return NULL;
> + if (mq_timedsend_errno == EINTR)
> + pthread_exit((void *)PTS_PASS);
> + else
> + pthread_exit((void *)PTS_FAIL);

Are these even used? The pthread_join() below has NULL parameter and the
mq_timedsend_errno is used directly.

The rests looks OK.

--
Cyril Hrubis
chrubis@suse.cz

------------------------------------------------------------------------------
Get 100% visibility into Java/.NET code with AppDynamics Lite!
It's a free troubleshooting tool designed for production.
Get down to code-level detail for bottlenecks, with <2% overhead.
Download for free and get started troubleshooting in minutes.