lib: fix a memory leak in FreeBSD

Two important changes:
* Centralize the thread teardown procedure;
* Save and restore thread mutex context to avoid losing the memory
  pointer;

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

1 files changed, 26 insertions, 11 deletions

diff --git a/lib/thread.c b/lib/thread.c
index 2c3db27c7b..e811bf88c8 100644
--- a/lib/thread.c
+++ b/lib/thread.c
@@ -58,6 +58,7 @@ pthread_key_t thread_current;
 pthread_mutex_t masters_mtx = PTHREAD_MUTEX_INITIALIZER;
 static struct list *masters;
 
+static void thread_free(struct thread_master *master, struct thread *thread);
 
 /* CLI start ---------------------------------------------------------------- */
 static unsigned int cpu_record_hash_key(struct cpu_thread_history *a)
@@ -538,6 +539,8 @@ static struct thread *thread_trim_head(struct thread_list *list)
 /* Move thread to unuse list. */
 static void thread_add_unuse(struct thread_master *m, struct thread *thread)
 {
+	pthread_mutex_t mtxc = thread->mtx;
+
 	assert(m != NULL && thread != NULL);
 	assert(thread->next == NULL);
 	assert(thread->prev == NULL);
@@ -546,10 +549,15 @@ static void thread_add_unuse(struct thread_master *m, struct thread *thread)
 	memset(thread, 0, sizeof(struct thread));
 	thread->type = THREAD_UNUSED;
 
-	if (m->unuse.count < THREAD_UNUSED_DEPTH)
+	/* Restore the thread mutex context. */
+	thread->mtx = mtxc;
+
+	if (m->unuse.count < THREAD_UNUSED_DEPTH) {
 		thread_list_add(&m->unuse, thread);
-	else
-		XFREE(MTYPE_THREAD, thread);
+		return;
+	}
+
+	thread_free(m, thread);
 }
 
 /* Free all unused thread. */
@@ -560,9 +568,8 @@ static void thread_list_free(struct thread_master *m, struct thread_list *list)
 
 	for (t = list->head; t; t = next) {
 		next = t->next;
-		XFREE(MTYPE_THREAD, t);
+		thread_free(m, t);
 		list->count--;
-		m->alloc--;
 	}
 }
 
@@ -576,8 +583,7 @@ static void thread_array_free(struct thread_master *m,
 		t = thread_array[index];
 		if (t) {
 			thread_array[index] = NULL;
-			XFREE(MTYPE_THREAD, t);
-			m->alloc--;
+			thread_free(m, t);
 		}
 	}
 	XFREE(MTYPE_THREAD_POLL, thread_array);
@@ -588,9 +594,8 @@ static void thread_queue_free(struct thread_master *m, struct pqueue *queue)
 	int i;
 
 	for (i = 0; i < queue->size; i++)
-		XFREE(MTYPE_THREAD, queue->array[i]);
+		thread_free(m, queue->array[i]);
 
-	m->alloc -= queue->size;
 	pqueue_delete(queue);
 }
 
@@ -608,8 +613,7 @@ void thread_master_free_unused(struct thread_master *m)
 	{
 		struct thread *t;
 		while ((t = thread_trim_head(&m->unuse)) != NULL) {
-			pthread_mutex_destroy(&t->mtx);
-			XFREE(MTYPE_THREAD, t);
+			thread_free(m, t);
 		}
 	}
 	pthread_mutex_unlock(&m->mtx);
@@ -728,6 +732,17 @@ static struct thread *thread_get(struct thread_master *m, uint8_t type,
 	return thread;
 }
 
+static void thread_free(struct thread_master *master, struct thread *thread)
+{
+	/* Update statistics. */
+	assert(master->alloc > 0);
+	master->alloc--;
+
+	/* Free allocated resources. */
+	pthread_mutex_destroy(&thread->mtx);
+	XFREE(MTYPE_THREAD, thread);
+}
+
 static int fd_poll(struct thread_master *m, struct pollfd *pfds, nfds_t pfdsize,
 		   nfds_t count, const struct timeval *timer_wait)
 {