diff -Naur /tmp/mosquitto-1.6.4/lib/connect.c ./lib/connect.c
--- /tmp/mosquitto-1.6.4/lib/connect.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/connect.c	2019-08-07 23:00:43.993719811 -0700
@@ -272,7 +272,7 @@
 	mosq->state = mosq_cs_disconnecting;
 	pthread_mutex_unlock(&mosq->state_mutex);
 
-	if(mosq->sock == INVALID_SOCKET) return MOSQ_ERR_NO_CONN;
+	// if(mosq->sock == INVALID_SOCKET) return MOSQ_ERR_NO_CONN;
 	return send__disconnect(mosq, reason_code, outgoing_properties);
 }
 
diff -Naur /tmp/mosquitto-1.6.4/lib/connect.c.rej ./lib/connect.c.rej
--- /tmp/mosquitto-1.6.4/lib/connect.c.rej	1969-12-31 16:00:00.000000000 -0800
+++ ./lib/connect.c.rej	2019-08-07 22:50:08.821782691 -0700
@@ -0,0 +1,11 @@
+--- vendor/mosquitto/lib/connect.c
++++ vendor/mosquitto/lib/connect.c
+@@ -206,7 +206,7 @@ int mosquitto_disconnect(struct mosquitto *mosq)
+ 	mosq->state = mosq_cs_disconnecting;
+ 	pthread_mutex_unlock(&mosq->state_mutex);
+ 
+-	if(mosq->sock == INVALID_SOCKET) return MOSQ_ERR_NO_CONN;
++//	if(mosq->sock == INVALID_SOCKET) return MOSQ_ERR_NO_CONN;
+ 	return send__disconnect(mosq);
+ }
+ 
diff -Naur /tmp/mosquitto-1.6.4/lib/handle_connack.c ./lib/handle_connack.c
--- /tmp/mosquitto-1.6.4/lib/handle_connack.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/handle_connack.c	2019-08-07 22:59:58.849996842 -0700
@@ -34,17 +34,29 @@
 	pthread_mutex_lock(&mosq->callback_mutex);
 	if(mosq->on_connect){
 		mosq->in_callback = true;
+                pthread_mutex_unlock(&mosq->callback_mutex);
+
 		mosq->on_connect(mosq, mosq->userdata, reason_code);
+
+                pthread_mutex_lock(&mosq->callback_mutex);
 		mosq->in_callback = false;
 	}
 	if(mosq->on_connect_with_flags){
 		mosq->in_callback = true;
+                pthread_mutex_unlock(&mosq->callback_mutex);
+
 		mosq->on_connect_with_flags(mosq, mosq->userdata, reason_code, connect_flags);
+
+                pthread_mutex_lock(&mosq->callback_mutex);
 		mosq->in_callback = false;
 	}
 	if(mosq->on_connect_v5){
 		mosq->in_callback = true;
+                pthread_mutex_unlock(&mosq->callback_mutex);
+
 		mosq->on_connect_v5(mosq, mosq->userdata, reason_code, connect_flags, properties);
+
+                pthread_mutex_lock(&mosq->callback_mutex);
 		mosq->in_callback = false;
 	}
 	pthread_mutex_unlock(&mosq->callback_mutex);
diff -Naur /tmp/mosquitto-1.6.4/lib/handle_connack.c.rej ./lib/handle_connack.c.rej
--- /tmp/mosquitto-1.6.4/lib/handle_connack.c.rej	1969-12-31 16:00:00.000000000 -0800
+++ ./lib/handle_connack.c.rej	2019-08-07 22:50:08.821782691 -0700
@@ -0,0 +1,36 @@
+--- vendor/mosquitto/lib/handle_connack.c
++++ vendor/mosquitto/lib/handle_connack.c
+@@ -39,22 +39,33 @@ int handle__connack(struct mosquitto *mosq)
+ 	if(rc) return rc;
+ 	log__printf(mosq, MOSQ_LOG_DEBUG, "Client %s received CONNACK (%d)", mosq->id, result);
+ 	pthread_mutex_lock(&mosq->callback_mutex);
++
+ 	if(mosq->on_connect){
+ 		mosq->in_callback = true;
++                pthread_mutex_unlock(&mosq->callback_mutex);
++
+ 		mosq->on_connect(mosq, mosq->userdata, result);
++
++                pthread_mutex_lock(&mosq->callback_mutex);
+ 		mosq->in_callback = false;
+ 	}
+ 	if(mosq->on_connect_with_flags){
+ 		mosq->in_callback = true;
++                pthread_mutex_unlock(&mosq->callback_mutex);
++
+ 		mosq->on_connect_with_flags(mosq, mosq->userdata, result, connect_flags);
++
++                pthread_mutex_lock(&mosq->callback_mutex);
+ 		mosq->in_callback = false;
+ 	}
+ 	pthread_mutex_unlock(&mosq->callback_mutex);
+ 	switch(result){
+ 		case 0:
++                        pthread_mutex_lock(&mosq->state_mutex);
+ 			if(mosq->state != mosq_cs_disconnecting){
+ 				mosq->state = mosq_cs_connected;
+ 			}
++                 	pthread_mutex_unlock(&mosq->state_mutex);
+ 			message__retry_check(mosq);
+ 			return MOSQ_ERR_SUCCESS;
+ 		case 1:
diff -Naur /tmp/mosquitto-1.6.4/lib/handle_ping.c ./lib/handle_ping.c
--- /tmp/mosquitto-1.6.4/lib/handle_ping.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/handle_ping.c	2019-08-07 23:08:46.798702752 -0700
@@ -55,9 +55,12 @@
 {
 	assert(mosq);
 
+	pthread_mutex_lock(&mosq->state_mutex);
 	if(mosq->state != mosq_cs_connected){
+            pthread_mutex_unlock(&mosq->state_mutex);
 		return MOSQ_ERR_PROTOCOL;
 	}
+	pthread_mutex_unlock(&mosq->state_mutex);
 
 	mosq->ping_t = 0; /* No longer waiting for a PINGRESP. */
 #ifdef WITH_BROKER
diff -Naur /tmp/mosquitto-1.6.4/lib/handle_pubackcomp.c ./lib/handle_pubackcomp.c
--- /tmp/mosquitto-1.6.4/lib/handle_pubackcomp.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/handle_pubackcomp.c	2019-08-07 23:02:44.792973223 -0700
@@ -50,9 +50,12 @@
 
 	assert(mosq);
 
+	pthread_mutex_lock(&mosq->state_mutex);
 	if(mosq->state != mosq_cs_connected){
+            pthread_mutex_unlock(&mosq->state_mutex);
 		return MOSQ_ERR_PROTOCOL;
 	}
+	pthread_mutex_unlock(&mosq->state_mutex);
 
 	pthread_mutex_lock(&mosq->msgs_out.mutex);
 	util__increment_send_quota(mosq);
diff -Naur /tmp/mosquitto-1.6.4/lib/handle_publish.c ./lib/handle_publish.c
--- /tmp/mosquitto-1.6.4/lib/handle_publish.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/handle_publish.c	2019-08-07 23:13:32.764887541 -0700
@@ -43,9 +43,12 @@
 
 	assert(mosq);
 
+	pthread_mutex_lock(&mosq->state_mutex);
 	if(mosq->state != mosq_cs_connected){
+            pthread_mutex_unlock(&mosq->state_mutex);
 		return MOSQ_ERR_PROTOCOL;
 	}
+	pthread_mutex_unlock(&mosq->state_mutex);
 
 	message = mosquitto__calloc(1, sizeof(struct mosquitto_message_all));
 	if(!message) return MOSQ_ERR_NOMEM;
@@ -119,7 +122,11 @@
 			pthread_mutex_lock(&mosq->callback_mutex);
 			if(mosq->on_message){
 				mosq->in_callback = true;
+                                pthread_mutex_unlock(&mosq->callback_mutex);
+
 				mosq->on_message(mosq, mosq->userdata, &message->msg);
+
+                                pthread_mutex_lock(&mosq->callback_mutex);
 				mosq->in_callback = false;
 			}
 			if(mosq->on_message_v5){
@@ -137,7 +144,11 @@
 			pthread_mutex_lock(&mosq->callback_mutex);
 			if(mosq->on_message){
 				mosq->in_callback = true;
+                                pthread_mutex_unlock(&mosq->callback_mutex);
+
 				mosq->on_message(mosq, mosq->userdata, &message->msg);
+
+                                pthread_mutex_lock(&mosq->callback_mutex);
 				mosq->in_callback = false;
 			}
 			if(mosq->on_message_v5){
diff -Naur /tmp/mosquitto-1.6.4/lib/handle_suback.c ./lib/handle_suback.c
--- /tmp/mosquitto-1.6.4/lib/handle_suback.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/handle_suback.c	2019-08-07 23:04:21.152373047 -0700
@@ -43,9 +43,12 @@
 
 	assert(mosq);
 
+	pthread_mutex_lock(&mosq->state_mutex);
 	if(mosq->state != mosq_cs_connected){
+            pthread_mutex_unlock(&mosq->state_mutex);
 		return MOSQ_ERR_PROTOCOL;
 	}
+	pthread_mutex_unlock(&mosq->state_mutex);
 
 #ifdef WITH_BROKER
 	log__printf(NULL, MOSQ_LOG_DEBUG, "Received SUBACK from %s", mosq->id);
diff -Naur /tmp/mosquitto-1.6.4/lib/packet_mosq.c ./lib/packet_mosq.c
--- /tmp/mosquitto-1.6.4/lib/packet_mosq.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/packet_mosq.c	2019-08-07 22:53:58.196306059 -0700
@@ -174,9 +174,12 @@
 #endif
 	}
 
+        pthread_mutex_lock(&mosq->callback_mutex);
 	if(mosq->in_callback == false && mosq->threaded == mosq_ts_none){
+                pthread_mutex_unlock(&mosq->callback_mutex);
 		return packet__write(mosq);
 	}else{
+                pthread_mutex_unlock(&mosq->callback_mutex);
 		return MOSQ_ERR_SUCCESS;
 	}
 #endif
@@ -217,14 +220,17 @@
 	}
 	pthread_mutex_unlock(&mosq->out_packet_mutex);
 
+	pthread_mutex_lock(&mosq->state_mutex);
 #if defined(WITH_TLS) && !defined(WITH_BROKER)
 	if((mosq->state == mosq_cs_connect_pending) || mosq->want_connect){
 #else
 	if(mosq->state == mosq_cs_connect_pending){
 #endif
+                pthread_mutex_unlock(&mosq->state_mutex);
 		pthread_mutex_unlock(&mosq->current_out_packet_mutex);
 		return MOSQ_ERR_SUCCESS;
 	}
+	pthread_mutex_unlock(&mosq->state_mutex);
 
 	while(mosq->current_out_packet){
 		packet = mosq->current_out_packet;
@@ -319,9 +325,12 @@
 	if(mosq->sock == INVALID_SOCKET){
 		return MOSQ_ERR_NO_CONN;
 	}
+        pthread_mutex_lock(&mosq->state_mutex);
 	if(mosq->state == mosq_cs_connect_pending){
+            pthread_mutex_unlock(&mosq->state_mutex);
 		return MOSQ_ERR_SUCCESS;
 	}
+            pthread_mutex_unlock(&mosq->state_mutex);
 
 	/* This gets called if pselect() indicates that there is network data
 	 * available - ie. at least one byte.  What we do depends on what data we
diff -Naur /tmp/mosquitto-1.6.4/lib/packet_mosq.c.rej ./lib/packet_mosq.c.rej
--- /tmp/mosquitto-1.6.4/lib/packet_mosq.c.rej	1969-12-31 16:00:00.000000000 -0800
+++ ./lib/packet_mosq.c.rej	2019-08-07 22:50:08.825782665 -0700
@@ -0,0 +1,28 @@
+--- vendor/mosquitto/lib/packet_mosq.c
++++ vendor/mosquitto/lib/packet_mosq.c
+@@ -141,9 +141,12 @@ int packet__queue(struct mosquitto *mosq, struct mosquitto__packet *packet)
+ #endif
+ 	}
+ 
++        pthread_mutex_lock(&mosq->callback_mutex);
+ 	if(mosq->in_callback == false && mosq->threaded == false){
++                pthread_mutex_unlock(&mosq->callback_mutex);
+ 		return packet__write(mosq);
+ 	}else{
++                pthread_mutex_unlock(&mosq->callback_mutex);
+ 		return MOSQ_ERR_SUCCESS;
+ 	}
+ #endif
+@@ -396,9 +402,12 @@ int packet__read(struct mosquitto *mosq)
+ 
+ 	if(!mosq) return MOSQ_ERR_INVAL;
+ 	if(mosq->sock == INVALID_SOCKET) return MOSQ_ERR_NO_CONN;
++        pthread_mutex_lock(&mosq->state_mutex);
+ 	if(mosq->state == mosq_cs_connect_pending){
++            pthread_mutex_unlock(&mosq->state_mutex);
+ 		return MOSQ_ERR_SUCCESS;
+ 	}
++        pthread_mutex_unlock(&mosq->state_mutex);
+ 
+ 	/* This gets called if pselect() indicates that there is network data
+ 	 * available - ie. at least one byte.  What we do depends on what data we
diff -Naur /tmp/mosquitto-1.6.4/lib/util_mosq.c ./lib/util_mosq.c
--- /tmp/mosquitto-1.6.4/lib/util_mosq.c	2019-08-01 12:50:01.000000000 -0700
+++ ./lib/util_mosq.c	2019-08-07 22:50:08.825782665 -0700
@@ -88,7 +88,9 @@
 	if(mosq->keepalive && mosq->sock != INVALID_SOCKET &&
 			(now >= next_msg_out || now - last_msg_in >= mosq->keepalive)){
 
+                pthread_mutex_lock(&mosq->state_mutex);
 		if(mosq->state == mosq_cs_connected && mosq->ping_t == 0){
+                        pthread_mutex_unlock(&mosq->state_mutex);
 			send__pingreq(mosq);
 			/* Reset last msg times to give the server time to send a pingresp */
 			pthread_mutex_lock(&mosq->msgtime_mutex);
@@ -110,7 +112,9 @@
 			pthread_mutex_lock(&mosq->callback_mutex);
 			if(mosq->on_disconnect){
 				mosq->in_callback = true;
+                                pthread_mutex_unlock(&mosq->callback_mutex);
 				mosq->on_disconnect(mosq, mosq->userdata, rc);
+                                pthread_mutex_lock(&mosq->callback_mutex);
 				mosq->in_callback = false;
 			}
 			if(mosq->on_disconnect_v5){