From 269756a171a63a2ff96f1973df11b6563020201a Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Thu, 27 Apr 2023 23:25:52 +0100
Subject: [PATCH] Fix high CPU use on slow TLS connect.

Closes #2794. Thanks to Evgeny S.
---
 ChangeLog.txt   |  1 +
 lib/loop.c      | 22 ++++++++++++----------
 lib/mosquitto.c | 13 +------------
 3 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 351eaad16c..655ddd0716 100644
--- a/ChangeLog.txt
+++ b/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.
diff --git a/lib/loop.c b/lib/loop.c
index 965294f052..0277a1d3a8 100644
--- a/lib/loop.c
+++ b/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){
diff --git a/lib/mosquitto.c b/lib/mosquitto.c
index 83bf42c2d7..a83d43a7f5 100644
--- a/lib/mosquitto.c
+++ b/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;
 }