uORB: join threads in unit tests

platforms/common/include/px4_platform_common/tasks.h

@@ -167,6 +167,9 @@ __EXPORT px4_task_t px4_task_spawn_cmd(const char *name,
 /** Deletes a task - does not do resource cleanup **/
 __EXPORT int px4_task_delete(px4_task_t pid);
 
+/** Wait for a task to exit. Returns 0 on success. Only supported on POSIX. **/
+__EXPORT int px4_task_join(px4_task_t pid);
+
 /** Send a signal to a task **/
 __EXPORT int px4_task_kill(px4_task_t pid, int sig);
 

platforms/common/uORB/uORB_tests/uORBTest_UnitTest.cpp

@@ -501,6 +501,8 @@ int uORBTest::UnitTest::test_multi2()
 		}
 	}
 
+	px4_task_join(pubsub_task);
+
 	for (int i = 0; i < num_instances; ++i) {
 		orb_unsubscribe(orb_data_fd[i]);
 	}
@@ -1032,6 +1034,8 @@ int uORBTest::UnitTest::test_queue_poll_notify()
 		}
 	}
 
+	px4_task_join(pubsub_task);
+
 	if (_num_messages_sent.load() != next_expected_val) {
 		return test_fail("number of sent and received messages mismatch (sent: %i, received: %i)",
 				 _num_messages_sent.load(), next_expected_val);
@@ -1087,6 +1091,7 @@ int uORBTest::UnitTest::latency_test(bool print)
 		return test_fail("failed launching task");
 	}
 
+	px4_task_join(pubsub_task);
 	orb_unadvertise(pfd0);
 
 	return pubsubtest_res.load();

platforms/posix/src/px4/common/tasks.cpp

@@ -274,6 +274,21 @@ px4_task_t px4_task_spawn_cmd(const char *name, int scheduler, int priority, int
 	return taskid;
 }
 
+int px4_task_join(px4_task_t id)
+{
+	if (id < PX4_MAX_TASKS) {
+		pthread_mutex_lock(&task_mutex);
+		pthread_t pid = taskmap[id].pid;
+		pthread_mutex_unlock(&task_mutex);
+
+		if (pid != 0) {
+			return pthread_join(pid, nullptr);
+		}
+	}
+
+	return -EINVAL;
+}
+
 int px4_task_delete(px4_task_t id)
 {
 	int rv = 0;