From b192d4cc46d8bda166116432ee28042e95750052 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jos=C3=A9=20Bollo?= <jose.bollo@iot.bzh>
Date: Wed, 7 Jun 2017 13:59:08 +0200
Subject: [PATCH] Fix concurrency issue in handling references
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Change-Id: Iaae331fbdadb88f26057a64193a026950dcb56e4
Signed-off-by: José Bollo <jose.bollo@iot.bzh>
---
 src/afb-session.c  | 13 +++++++------
 src/afb-ws-json1.c |  4 ++--
 src/locale-root.c  | 12 ++++++------
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/src/afb-session.c b/src/afb-session.c
index 523cbf04..536cdbcc 100644
--- a/src/afb-session.c
+++ b/src/afb-session.c
@@ -324,7 +324,7 @@ struct afb_session *afb_session_get (const char *uuid, int *created)
 struct afb_session *afb_session_addref(struct afb_session *session)
 {
 	if (session != NULL)
-		session->refcount++;
+		__atomic_add_fetch(&session->refcount, 1, __ATOMIC_RELAXED);
 	return session;
 }
 
@@ -332,11 +332,12 @@ void afb_session_unref(struct afb_session *session)
 {
 	if (session != NULL) {
 		assert(session->refcount != 0);
-		--session->refcount;
-		if (session->refcount == 0 && session->uuid[0] == 0) {
-			destroy (session);
-			pthread_mutex_destroy(&session->mutex);
-			free(session);
+		if (!__atomic_sub_fetch(&session->refcount, 1, __ATOMIC_RELAXED)) {
+			if (session->uuid[0] == 0) {
+				destroy (session);
+				pthread_mutex_destroy(&session->mutex);
+				free(session);
+			}
 		}
 	}
 }
diff --git a/src/afb-ws-json1.c b/src/afb-ws-json1.c
index 45e1cdb0..c796b17c 100644
--- a/src/afb-ws-json1.c
+++ b/src/afb-ws-json1.c
@@ -145,13 +145,13 @@ error:
 
 static struct afb_ws_json1 *aws_addref(struct afb_ws_json1 *ws)
 {
-	ws->refcount++;
+	__atomic_add_fetch(&ws->refcount, 1, __ATOMIC_RELAXED);
 	return ws;
 }
 
 static void aws_unref(struct afb_ws_json1 *ws)
 {
-	if (--ws->refcount == 0) {
+	if (!__atomic_sub_fetch(&ws->refcount, 1, __ATOMIC_RELAXED)) {
 		afb_evt_listener_unref(ws->listener);
 		afb_wsj1_unref(ws->wsj1);
 		if (ws->cleanup != NULL)
diff --git a/src/locale-root.c b/src/locale-root.c
index ee88f3f5..ece4456f 100644
--- a/src/locale-root.c
+++ b/src/locale-root.c
@@ -331,7 +331,7 @@ struct locale_root *locale_root_create_at(int dirfd, const char *path)
  */
 struct locale_root *locale_root_addref(struct locale_root *root)
 {
-	root->refcount++;
+	__atomic_add_fetch(&root->refcount, 1, __ATOMIC_RELAXED);
 	return root;
 }
 
@@ -341,7 +341,7 @@ struct locale_root *locale_root_addref(struct locale_root *root)
  */
 static void internal_unref(struct locale_root *root)
 {
-	if (!--root->intcount) {
+	if (!__atomic_sub_fetch(&root->intcount, 1, __ATOMIC_RELAXED)) {
 		clear_container(&root->container);
 		close(root->rootfd);
 		free(root);
@@ -356,7 +356,7 @@ void locale_root_unref(struct locale_root *root)
 {
 	size_t i;
 
-	if (root != NULL && !--root->refcount) {
+	if (root && !__atomic_sub_fetch(&root->refcount, 1, __ATOMIC_RELAXED)) {
 		/* clear circular references through searchs */
 		for (i = 0 ; i < LRU_COUNT ; i++)
 			locale_search_unref(root->lru[i]);
@@ -420,7 +420,7 @@ static struct locale_search *create_search(struct locale_root *root, const char
 		errno = ENOMEM;
 	} else {
 		/* init */
-		root->intcount++;
+		__atomic_add_fetch(&root->intcount, 1, __ATOMIC_RELAXED);
 		search->root = root;
 		search->head = NULL;
 		search->refcount = 1;
@@ -541,7 +541,7 @@ struct locale_search *locale_root_search(struct locale_root *root, const char *d
  */
 struct locale_search *locale_search_addref(struct locale_search *search)
 {
-	search->refcount++;
+	__atomic_add_fetch(&search->refcount, 1, __ATOMIC_RELAXED);
 	return search;
 }
 
@@ -552,7 +552,7 @@ void locale_search_unref(struct locale_search *search)
 {
 	struct locale_search_node *it, *nx;
 
-	if (search && !--search->refcount) {
+	if (search && !__atomic_sub_fetch(&search->refcount, 1, __ATOMIC_RELAXED)) {
 		it = search->head;
 		while(it != NULL) {
 			nx = it->next;
-- 
2.16.6