Verify that sem_wait() doesn't return zero without decrementing the

semaphore when a signal is received.  It should either resume waiting
or return EINTR, preferrably the former.

1 files changed, 52 insertions, 3 deletions

diff --git a/regress/lib/libpthread/semaphore/sem_wait/sem_wait.c b/regress/lib/libpthread/semaphore/sem_wait/sem_wait.c
index efc3e932ffe..725b639c634 100644
--- a/regress/lib/libpthread/semaphore/sem_wait/sem_wait.c
+++ b/regress/lib/libpthread/semaphore/sem_wait/sem_wait.c
@@ -1,23 +1,35 @@
-/*	$OpenBSD: sem_wait.c,v 1.2 2012/03/03 09:36:26 guenther Exp $	*/
+/*	$OpenBSD: sem_wait.c,v 1.3 2012/03/03 09:51:00 guenther Exp $	*/
 /*
  * Martin Pieuchot <mpi@openbsd.org>, 2011. Public Domain.
  */
 
+#include <err.h>
 #include <errno.h>
 #include <unistd.h>
 #include <semaphore.h>
+#include <signal.h>
 #include <pthread.h>
 #include "test.h"
 
 
 void *waiter(void *arg);
 
+void
+handler(int sig)
+{
+	static char message[] = "got sig\n";
+
+	write(STDERR_FILENO, message, sizeof(message) - 1);
+}
+
 sem_t sem;
+volatile int posted = 0, eintr_ok = 0;
 
 int
 main(int argc, char **argv)
 {
 	pthread_t th;
+	struct sigaction sa;
 
 	CHECKn(sem_wait(&sem));
 	ASSERT(errno == EINVAL);
@@ -28,9 +40,31 @@ main(int argc, char **argv)
 
 	sleep(1);
 
+	printf("expect: sem_destroy on semaphore with waiters!\n");
 	CHECKn(sem_destroy(&sem));
 	ASSERT(errno == EBUSY);
 
+	posted = 1;
+	CHECKr(sem_post(&sem));
+	CHECKr(pthread_join(th, NULL));
+
+	/* test that sem_wait() resumes after handling a signal */
+	memset(&sa, 0, sizeof sa);
+	sa.sa_handler = &handler;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = 0;
+	if (sigaction(SIGUSR1, &sa, NULL))
+		err(1, "sigaction");
+	posted = 0;
+	CHECKr(pthread_create(&th, NULL, waiter, &sem));
+	sleep(1);
+	fprintf(stderr, "sending sig\n");
+	eintr_ok = 1;
+	pthread_kill(th, SIGUSR1);
+	sleep(1);
+	fprintf(stderr, "posting\n");
+	posted = 1;
+	eintr_ok = 0;
 	CHECKr(sem_post(&sem));
 	CHECKr(pthread_join(th, NULL));
 
@@ -43,8 +77,23 @@ void *
 waiter(void *arg)
 {
 	sem_t *semp = arg;
-
-	CHECKr(sem_wait(semp));
+	int value;
+	int r;
+
+	r = sem_wait(semp);
+	CHECKr(sem_getvalue(semp, &value));
+	if (r == 0) {
+		ASSERT(value == 0);
+		ASSERT(posted != 0);
+	} else {
+		ASSERT(r == -1);
+		ASSERT(errno == EINTR);
+		ASSERT(eintr_ok);
+		if (posted)
+			ASSERT(value == 1);
+		else
+			ASSERT(value == 0);
+	}
 
 	return (NULL);
 }