mq_notify: join worker thread before returning in error path

this avoids leaving behind transient resource consumption whose
cleanup is subject to scheduling behavior.

diff --git a/src/mq/mq_notify.c b/src/mq/mq_notify.c
index 217d888..8109dfb 100644 (file)
--- a/src/mq/mq_notify.c
+++ b/src/mq/mq_notify.c
@@ -35,6 +35,7 @@ static void *start(void *p)
        sem_post(&args->sem);
        if (err) return 0;
 
+       pthread_detach(pthread_self());
        n = recv(s, buf, sizeof(buf), MSG_NOSIGNAL|MSG_WAITALL);
        close(s);
        if (n==sizeof buf && buf[sizeof buf - 1] == 1)
@@ -60,7 +61,7 @@ int mq_notify(mqd_t mqd, const struct sigevent *sev)
 
        if (sev->sigev_notify_attributes) attr = *sev->sigev_notify_attributes;
        else pthread_attr_init(&attr);
-       pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+       pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
        sem_init(&args.sem, 0, 0);
 
        if (pthread_create(&td, &attr, start, &args)) {
@@ -71,14 +72,16 @@ int mq_notify(mqd_t mqd, const struct sigevent *sev)
 
        pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
        sem_wait(&args.sem);
-       pthread_setcancelstate(cs, 0);
        sem_destroy(&args.sem);
 
        if (args.err) {
                __syscall(SYS_close, s);
+               pthread_join(td, 0);
+               pthread_setcancelstate(cs, 0);
                errno = args.err;
                return -1;
        }
 
+       pthread_setcancelstate(cs, 0);
        return 0;
 }