X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-ust-comm.c;h=3959568b8366cd54a3661ad375d725adf0290815;hb=8d8c99c9eed441026e2dad93b685f2004034a321;hp=8a568328dea8c0701fe5b3705aa63711610b2a19;hpb=8e696cfa579df0d75368a36d049e9c99b24e53f4;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 8a568328..3959568b 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -106,6 +106,14 @@ static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER;
 /* Should the ust comm thread quit ? */
 static int lttng_ust_comm_should_quit;
 
+/*
+ * This variable can be tested by applications to check whether
+ * lttng-ust is loaded. They simply have to define their own
+ * "lttng_ust_loaded" weak symbol, and test it. It is set to 1 by the
+ * library constructor.
+ */
+int lttng_ust_loaded __attribute__((weak));
+
 /*
  * Return 0 on success, -1 if should quit.
  * The lock is taken in both cases.
@@ -1295,6 +1303,15 @@ void *ust_listener_thread(void *arg)
 	int sock, ret, prev_connect_failed = 0, has_waited = 0;
 	long timeout;
 
+	/*
+	 * If available, add '-ust' to the end of this thread's
+	 * process name
+	 */
+	ret = lttng_ust_setustprocname();
+	if (ret) {
+		ERR("Unable to set UST process name");
+	}
+
 	/* Restart trying to connect to the session daemon */
 restart:
 	if (prev_connect_failed) {
@@ -1565,6 +1582,8 @@ void __attribute__((constructor)) lttng_ust_init(void)
 	lttng_fixup_procname_tls();
 	lttng_fixup_ust_mutex_nest_tls();
 
+	lttng_ust_loaded = 1;
+
 	/*
 	 * We want precise control over the order in which we construct
 	 * our sub-libraries vs starting to receive commands from
@@ -1590,7 +1609,9 @@ void __attribute__((constructor)) lttng_ust_init(void)
 	timeout_mode = get_constructor_timeout(&constructor_timeout);
 
 	ret = sem_init(&constructor_wait, 0, 0);
-	assert(!ret);
+	if (ret) {
+		PERROR("sem_init");
+	}
 
 	ret = setup_local_apps();
 	if (ret) {
@@ -1655,17 +1676,34 @@ void __attribute__((constructor)) lttng_ust_init(void)
 			ret = sem_timedwait(&constructor_wait,
 					&constructor_timeout);
 		} while (ret < 0 && errno == EINTR);
-		if (ret < 0 && errno == ETIMEDOUT) {
-			ERR("Timed out waiting for lttng-sessiond");
-		} else {
-			assert(!ret);
+		if (ret < 0) {
+			switch (errno) {
+			case ETIMEDOUT:
+				ERR("Timed out waiting for lttng-sessiond");
+				break;
+			case EINVAL:
+				PERROR("sem_timedwait");
+				break;
+			default:
+				ERR("Unexpected error \"%s\" returned by sem_timedwait",
+					strerror(errno));
+			}
 		}
 		break;
 	case -1:/* wait forever */
 		do {
 			ret = sem_wait(&constructor_wait);
 		} while (ret < 0 && errno == EINTR);
-		assert(!ret);
+		if (ret < 0) {
+			switch (errno) {
+			case EINVAL:
+				PERROR("sem_wait");
+				break;
+			default:
+				ERR("Unexpected error \"%s\" returned by sem_wait",
+					strerror(errno));
+			}
+		}
 		break;
 	case 0:	/* no timeout */
 		break;