Fix deadlock on mountpoint destroy during RTSP reconnect (#2700)

meetecho · Jun 15, 2021 · 1d50e06 · 1d50e06
1 parent a467088
commit 1d50e06
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Showing 2 changed files with 34 additions and 18 deletions.
diff --git a/mutex.h b/mutex.h
@@ -28,17 +28,23 @@ typedef pthread_mutex_t janus_mutex;
 /*! \brief Janus mutex destruction */
 #define janus_mutex_destroy(a) pthread_mutex_destroy(a)
 /*! \brief Janus mutex lock without debug */
-#define janus_mutex_lock_nodebug(a) pthread_mutex_lock(a);
+#define janus_mutex_lock_nodebug(a) pthread_mutex_lock(a)
 /*! \brief Janus mutex lock with debug (prints the line that locked a mutex) */
-#define janus_mutex_lock_debug(a) { JANUS_PRINT("[%s:%s:%d:lock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); pthread_mutex_lock(a); };
+#define janus_mutex_lock_debug(a) { JANUS_PRINT("[%s:%s:%d:lock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); pthread_mutex_lock(a); }
 /*! \brief Janus mutex lock wrapper (selective locking debug) */
-#define janus_mutex_lock(a) { if(!lock_debug) { janus_mutex_lock_nodebug(a); } else { janus_mutex_lock_debug(a); } };
+#define janus_mutex_lock(a) { if(!lock_debug) { janus_mutex_lock_nodebug(a); } else { janus_mutex_lock_debug(a); } }
+/*! \brief Janus mutex try lock without debug */
+#define janus_mutex_trylock_nodebug(a) { ret = pthread_mutex_trylock(a); }
+/*! \brief Janus mutex try lock with debug (prints the line that tried to lock a mutex) */
+#define janus_mutex_trylock_debug(a) { JANUS_PRINT("[%s:%s:%d:trylock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); ret = pthread_mutex_trylock(a); }
+/*! \brief Janus mutex try lock wrapper (selective locking debug) */
+#define janus_mutex_trylock(a) ({ int ret; if(!lock_debug) { janus_mutex_trylock_nodebug(a); } else { janus_mutex_trylock_debug(a); } ret; })
 /*! \brief Janus mutex unlock without debug */
-#define janus_mutex_unlock_nodebug(a) pthread_mutex_unlock(a);
+#define janus_mutex_unlock_nodebug(a) pthread_mutex_unlock(a)
 /*! \brief Janus mutex unlock with debug (prints the line that unlocked a mutex) */
-#define janus_mutex_unlock_debug(a) { JANUS_PRINT("[%s:%s:%d:unlock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); pthread_mutex_unlock(a); };
+#define janus_mutex_unlock_debug(a) { JANUS_PRINT("[%s:%s:%d:unlock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); pthread_mutex_unlock(a); }
 /*! \brief Janus mutex unlock wrapper (selective locking debug) */
-#define janus_mutex_unlock(a) { if(!lock_debug) { janus_mutex_unlock_nodebug(a); } else { janus_mutex_unlock_debug(a); } };
+#define janus_mutex_unlock(a) { if(!lock_debug) { janus_mutex_unlock_nodebug(a); } else { janus_mutex_unlock_debug(a); } }
 
 /*! \brief Janus condition implementation */
 typedef pthread_cond_t janus_condition;
@@ -72,17 +78,23 @@ typedef GMutex janus_mutex;
 /*! \brief Janus mutex destruction */
 #define janus_mutex_destroy(a) g_mutex_clear(a)
 /*! \brief Janus mutex lock without debug */
-#define janus_mutex_lock_nodebug(a) g_mutex_lock(a);
+#define janus_mutex_lock_nodebug(a) g_mutex_lock(a)
 /*! \brief Janus mutex lock with debug (prints the line that locked a mutex) */
-#define janus_mutex_lock_debug(a) { JANUS_PRINT("[%s:%s:%d:lock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); g_mutex_lock(a); };
+#define janus_mutex_lock_debug(a) { JANUS_PRINT("[%s:%s:%d:lock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); g_mutex_lock(a); }
 /*! \brief Janus mutex lock wrapper (selective locking debug) */
-#define janus_mutex_lock(a) { if(!lock_debug) { janus_mutex_lock_nodebug(a); } else { janus_mutex_lock_debug(a); } };
+#define janus_mutex_lock(a) { if(!lock_debug) { janus_mutex_lock_nodebug(a); } else { janus_mutex_lock_debug(a); } }
+/*! \brief Janus mutex try lock without debug */
+#define janus_mutex_trylock_nodebug(a) { ret = g_mutex_trylock(a); }
+/*! \brief Janus mutex try lock with debug (prints the line that tried to lock a mutex) */
+#define janus_mutex_trylock_debug(a) { JANUS_PRINT("[%s:%s:%d:trylock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); ret = g_mutex_trylock(a); }
+/*! \brief Janus mutex try lock wrapper (selective locking debug) */
+#define janus_mutex_trylock(a) ({ gboolean ret; if(!lock_debug) { janus_mutex_trylock_nodebug(a); } else { janus_mutex_trylock_debug(a); } ret; })
 /*! \brief Janus mutex unlock without debug */
-#define janus_mutex_unlock_nodebug(a) g_mutex_unlock(a);
+#define janus_mutex_unlock_nodebug(a) g_mutex_unlock(a)
 /*! \brief Janus mutex unlock with debug (prints the line that unlocked a mutex) */
-#define janus_mutex_unlock_debug(a) { JANUS_PRINT("[%s:%s:%d:unlock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); g_mutex_unlock(a); };
+#define janus_mutex_unlock_debug(a) { JANUS_PRINT("[%s:%s:%d:unlock] %p\n", __FILE__, __FUNCTION__, __LINE__, a); g_mutex_unlock(a); }
 /*! \brief Janus mutex unlock wrapper (selective locking debug) */
-#define janus_mutex_unlock(a) { if(!lock_debug) { janus_mutex_unlock_nodebug(a); } else { janus_mutex_unlock_debug(a); } };
+#define janus_mutex_unlock(a) { if(!lock_debug) { janus_mutex_unlock_nodebug(a); } else { janus_mutex_unlock_debug(a); } }
 
 /*! \brief Janus condition implementation */
 typedef GCond janus_condition;

diff --git a/plugins/janus_streaming.c b/plugins/janus_streaming.c
@@ -6489,14 +6489,18 @@ static int janus_streaming_rtsp_connect_to_server(janus_streaming_mountpoint *mp
 	int asport = 0, asport_rtcp = 0;
 	multiple_fds audio_fds = {-1, -1};
 
-	if(g_atomic_int_get(&mp->destroyed)) {
-		curl_easy_cleanup(curl);
-		g_free(curldata->buffer);
-		g_free(curldata);
-		return -8;
+	while (!janus_mutex_trylock(&mountpoints_mutex)) {
+		if(g_atomic_int_get(&mp->destroyed)) {
+			JANUS_LOG(LOG_WARN, "[%s] Destroying mountpoint while trying to reconnect, aborting\n", mp->name);
+			curl_easy_cleanup(curl);
+			g_free(curldata->buffer);
+			g_free(curldata);
+			return -8;
+		}
+
+		g_usleep(1000);
 	}
 
-	janus_mutex_lock(&mountpoints_mutex);
 	/* Parse both video and audio first before proceed to setup as curldata will be reused */
 	int vresult = -1;
 	if(dovideo) {