Fix high CPU use on slow TLS connect.

Closes #2794. Thanks to Evgeny S.

ChangeLog.txt

@@ -17,6 +17,7 @@ Client library:
   problem of the client OS sleeping and the client hence not being able to
   calculate the actual time for keepalive purposes. Closes #2760.
 - Fix default settings incorrectly allowing TLS v1.1. Closes #2722.
+- Fix high CPU use on slow TLS connect. Closes #2794.
 
 Clients:
 - Fix incorrect topic-alias property value in mosquitto_sub json output.

lib/loop.c

@@ -63,20 +63,22 @@ int mosquitto_loop(struct mosquitto *mosq, int timeout, int max_packets)
 	if(mosq->sock != INVALID_SOCKET){
 		maxfd = mosq->sock;
 		FD_SET(mosq->sock, &readfds);
-		pthread_mutex_lock(&mosq->current_out_packet_mutex);
+		if(mosq->want_write){
-		pthread_mutex_lock(&mosq->out_packet_mutex);
-		if(mosq->out_packet || mosq->current_out_packet){
 			FD_SET(mosq->sock, &writefds);
-		}
+		}else{
 #ifdef WITH_TLS
-		if(mosq->ssl){
+			if(mosq->ssl == NULL || SSL_is_init_finished(mosq->ssl))
-			if(mosq->want_write){
+#endif
-				FD_SET(mosq->sock, &writefds);
+			{
+				pthread_mutex_lock(&mosq->current_out_packet_mutex);
+				pthread_mutex_lock(&mosq->out_packet_mutex);
+				if(mosq->out_packet || mosq->current_out_packet){
+					FD_SET(mosq->sock, &writefds);
+				}
+				pthread_mutex_unlock(&mosq->out_packet_mutex);
+				pthread_mutex_unlock(&mosq->current_out_packet_mutex);
 			}
 		}
-#endif
-		pthread_mutex_unlock(&mosq->out_packet_mutex);
-		pthread_mutex_unlock(&mosq->current_out_packet_mutex);
 	}else{
 #ifdef WITH_SRV
 		if(mosq->achan){

lib/mosquitto.c

@@ -332,18 +332,7 @@ int mosquitto_socket(struct mosquitto *mosq)
 
 bool mosquitto_want_write(struct mosquitto *mosq)
 {
-	bool result = false;
+	return mosq->out_packet || mosq->current_out_packet || mosq->want_write;
-	if(mosq->out_packet || mosq->current_out_packet){
-		result = true;
-	}
-#ifdef WITH_TLS
-	if(mosq->ssl){
-		if (mosq->want_write) {
-			result = true;
-		}
-	}
-#endif
-	return result;
 }