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);
- pthread_mutex_lock(&mosq->out_packet_mutex);
- if(mosq->out_packet || mosq->current_out_packet){
+ if(mosq->want_write){
  FD_SET(mosq->sock, &writefds);
- }
+ }else{
 #ifdef WITH_TLS
- if(mosq->ssl){
- if(mosq->want_write){
- FD_SET(mosq->sock, &writefds);
+ if(mosq->ssl == NULL || SSL_is_init_finished(mosq->ssl))
+#endif
+ {
+ 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;
- 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;
+ return mosq->out_packet || mosq->current_out_packet || mosq->want_write;
 }