From e8185ddaa74234c2c37aa529e711cddfc7cede91 Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Wed, 18 May 2016 14:05:08 +0100
Subject: [PATCH] [166] Don't cancel external threads.
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libmosquitto shouldn't cancel threads it didn't create. This change
allows us to keep track of whether threads were created by the library
or by external code.

Thanks to Josip Ćavar.

Bug: https://github.com/eclipse/mosquitto/issues/166
---
 ChangeLog.txt            |  2 ++
 lib/mosquitto.c          |  6 +++---
 lib/mosquitto_internal.h |  8 +++++++-
 lib/net_mosq.c           |  2 +-
 lib/thread_mosq.c        | 14 +++++++++-----
 5 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 963e67af..698bbe12 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -19,6 +19,8 @@ Client library:
 - Fix the case where a message received just before the keepalive timer
   expired would cause the client to miss the keepalive timer.
 - Return value of pthread_create is now checked.
+- _mosquitto_destroy should not cancel threads that weren't created by
+  libmosquitto. Closes #166.
 
 Clients:
 - Handle some unchecked malloc() calls. Closes #1.
diff --git a/lib/mosquitto.c b/lib/mosquitto.c
index ccc4af50..880657df 100644
--- a/lib/mosquitto.c
+++ b/lib/mosquitto.c
@@ -197,7 +197,7 @@ int mosquitto_reinitialise(struct mosquitto *mosq, const char *id, bool clean_se
 	mosq->reconnect_delay = 1;
 	mosq->reconnect_delay_max = 1;
 	mosq->reconnect_exponential_backoff = false;
-	mosq->threaded = false;
+	mosq->threaded = mosq_ts_none;
 #ifdef WITH_TLS
 	mosq->ssl = NULL;
 	mosq->tls_cert_reqs = SSL_VERIFY_PEER;
@@ -278,10 +278,10 @@ void _mosquitto_destroy(struct mosquitto *mosq)
 	if(!mosq) return;
 
 #ifdef WITH_THREADING
-	if(mosq->threaded && !pthread_equal(mosq->thread_id, pthread_self())){
+	if(mosq->threaded == mosq_ts_self && !pthread_equal(mosq->thread_id, pthread_self())){
 		pthread_cancel(mosq->thread_id);
 		pthread_join(mosq->thread_id, NULL);
-		mosq->threaded = false;
+		mosq->threaded = mosq_ts_none;
 	}
 
 	if(mosq->id){
diff --git a/lib/mosquitto_internal.h b/lib/mosquitto_internal.h
index 99310302..4b4cf858 100644
--- a/lib/mosquitto_internal.h
+++ b/lib/mosquitto_internal.h
@@ -112,6 +112,12 @@ enum _mosquitto_protocol {
 	mosq_p_mqtts = 3
 };
 
+enum mosquitto__threaded_state {
+	mosq_ts_none,		/* No threads in use */
+	mosq_ts_self,		/* Threads started by libmosquitto */
+	mosq_ts_external	/* Threads started by external code */
+};
+
 enum _mosquitto_transport {
 	mosq_t_invalid = 0,
 	mosq_t_tcp = 1,
@@ -245,7 +251,7 @@ struct mosquitto {
 	unsigned int reconnect_delay;
 	unsigned int reconnect_delay_max;
 	bool reconnect_exponential_backoff;
-	bool threaded;
+	char threaded;
 	struct _mosquitto_packet *out_packet_last;
 	int inflight_messages;
 	int max_inflight_messages;
diff --git a/lib/net_mosq.c b/lib/net_mosq.c
index 402e4a79..f18d41b2 100644
--- a/lib/net_mosq.c
+++ b/lib/net_mosq.c
@@ -187,7 +187,7 @@ int _mosquitto_packet_queue(struct mosquitto *mosq, struct _mosquitto_packet *pa
 #endif
 	}
 
-	if(mosq->in_callback == false && mosq->threaded == false){
+	if(mosq->in_callback == false && mosq->threaded == mosq_ts_none){
 		return _mosquitto_packet_write(mosq);
 	}else{
 		return MOSQ_ERR_SUCCESS;
diff --git a/lib/thread_mosq.c b/lib/thread_mosq.c
index dbb511df..93c5b635 100644
--- a/lib/thread_mosq.c
+++ b/lib/thread_mosq.c
@@ -28,9 +28,9 @@ void *_mosquitto_thread_main(void *obj);
 int mosquitto_loop_start(struct mosquitto *mosq)
 {
 #ifdef WITH_THREADING
-	if(!mosq || mosq->threaded) return MOSQ_ERR_INVAL;
+	if(!mosq || mosq->threaded != mosq_ts_none) return MOSQ_ERR_INVAL;
 
-	mosq->threaded = true;
+	mosq->threaded = mosq_ts_self;
 	if(!pthread_create(&mosq->thread_id, NULL, _mosquitto_thread_main, mosq)){
 		return MOSQ_ERR_SUCCESS;
 	}else{
@@ -48,7 +48,7 @@ int mosquitto_loop_stop(struct mosquitto *mosq, bool force)
 	char sockpair_data = 0;
 #  endif
 
-	if(!mosq || !mosq->threaded) return MOSQ_ERR_INVAL;
+	if(!mosq || mosq->threaded != mosq_ts_self) return MOSQ_ERR_INVAL;
 
 
 	/* Write a single byte to sockpairW (connected to sockpairR) to break out
@@ -67,7 +67,7 @@ int mosquitto_loop_stop(struct mosquitto *mosq, bool force)
 	}
 	pthread_join(mosq->thread_id, NULL);
 	mosq->thread_id = pthread_self();
-	mosq->threaded = false;
+	mosq->threaded = mosq_ts_none;
 
 	return MOSQ_ERR_SUCCESS;
 #else
@@ -106,7 +106,11 @@ int mosquitto_threaded_set(struct mosquitto *mosq, bool threaded)
 {
 	if(!mosq) return MOSQ_ERR_INVAL;
 
-	mosq->threaded = threaded;
+	if(threaded){
+		mosq->threaded = mosq_ts_external;
+	}else{
+		mosq->threaded = mosq_ts_none;
+	}
 
 	return MOSQ_ERR_SUCCESS;
 }