Fix mosquitto_loop_stop() hangs on Windows.

Before this commit, mosquitto_loop_forever() would not always terminate on Windows when calling mosquitto_loop_stop() with the force flag set to true. This commit adds explicit thread cancellation points in mosquitto_loop_forever() as described in issue eclipse#117 to ensure that mosquitto_loop_stop() does not hang when joining the Mosquitto thread. Closes eclipse#117. Signed-off-by: Sigmund Vik <[email protected]>
SigmundVik · Jul 12, 2020 · 18e995e · 18e995e
1 parent 20972a2
commit 18e995e
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Showing 2 changed files with 28 additions and 3 deletions.
diff --git a/lib/loop.c b/lib/loop.c
@@ -243,19 +243,28 @@ static int interruptible_sleep(struct mosquitto *mosq, unsigned long reconnect_d
 }
 
 
-int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
+int mosquitto__loop_forever(struct mosquitto *mosq, int timeout, int max_packets, bool explicit_cancellation_points)
 {
  int run = 1;
  int rc;
  unsigned long reconnect_delay;
  int state;
 
+#ifndef WIN32
+ UNUSED(explicit_cancellation_points);
+#endif
+
  if(!mosq) return MOSQ_ERR_INVAL;
 
  mosq->reconnects = 0;
 
  while(run){
  do{
+#ifdef WIN32
+ if(explicit_cancellation_points) {
+ pthread_testcancel();
+ }
+#endif
  rc = mosquitto_loop(mosq, timeout, max_packets);
  }while(run && rc == MOSQ_ERR_SUCCESS);
  /* Quit after fatal errors. */
@@ -280,6 +289,11 @@ int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
  return rc;
  }
  do{
+#ifdef WIN32
+ if(explicit_cancellation_points) {
+ pthread_testcancel();
+ }
+#endif
  rc = MOSQ_ERR_SUCCESS;
  state = mosquitto__get_state(mosq);
  if(state == mosq_cs_disconnecting || state == mosq_cs_disconnected){
@@ -317,6 +331,12 @@ int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
 }
 
 
+int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
+{
+ return mosquitto__loop_forever(mosq, timeout, max_packets, false);
+}
+
+
 int mosquitto_loop_misc(struct mosquitto *mosq)
 {
  if(!mosq) return MOSQ_ERR_INVAL;

diff --git a/lib/thread_mosq.c b/lib/thread_mosq.c
@@ -77,14 +77,19 @@ int mosquitto_loop_stop(struct mosquitto *mosq, bool force)
 }
 
 #ifdef WITH_THREADING
+int mosquitto__loop_forever(struct mosquitto *mosq, int timeout, int max_packets, bool explicit_cancellation_points);
+
 void *mosquitto__thread_main(void *obj)
 {
  struct mosquitto *mosq = obj;
  int state;
 #ifndef WIN32
+ bool explicit_cancellation_points = false;
  struct timespec ts;
  ts.tv_sec = 0;
  ts.tv_nsec = 10000000;
+#else
+ bool explicit_cancellation_points = true;
 #endif
 
  if(!mosq) return NULL;
@@ -104,10 +109,10 @@ void *mosquitto__thread_main(void *obj)
 
  if(!mosq->keepalive){
  /* Sleep for a day if keepalive disabled. */
- mosquitto_loop_forever(mosq, 1000*86400, 1);
+ mosquitto__loop_forever(mosq, 1000*86400, 1, explicit_cancellation_points);
  }else{
  /* Sleep for our keepalive value. publish() etc. will wake us up. */
- mosquitto_loop_forever(mosq, mosq->keepalive*1000, 1);
+ mosquitto__loop_forever(mosq, mosq->keepalive*1000, 1, explicit_cancellation_points);
  }
 
  return obj;