Clean up find_idle_thread function and use atomic operations for dynamic thread count.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@48567 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 23c11b922a505b7057344ac86add0f607f040981..865319d2ca409c30a35d08956680259523a66a77 100644 (file)
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -890,37 +890,42 @@ static struct iax2_thread *find_idle_thread(void)
 {
        struct iax2_thread *thread = NULL;
 
-       /* Pop the head of the list off */
+       /* Pop the head of the idle list off */
        AST_LIST_LOCK(&idle_list);
        thread = AST_LIST_REMOVE_HEAD(&idle_list, list);
        AST_LIST_UNLOCK(&idle_list);
 
-       /* If no idle thread is available from the regular list, try dynamic */
-       if (thread == NULL) {
-               AST_LIST_LOCK(&dynamic_list);
-               thread = AST_LIST_FIRST(&dynamic_list);
-               if (thread != NULL) {
-                       AST_LIST_REMOVE(&dynamic_list, thread, list);
-               }
-               /* Make sure we absolutely have a thread... if not, try to make one if allowed */
-               if (thread == NULL && iaxmaxthreadcount > iaxdynamicthreadcount) {
-                       /* We need to MAKE a thread! */
-                       thread = ast_calloc(1, sizeof(*thread));
-                       if (thread != NULL) {
-                               thread->threadnum = iaxdynamicthreadcount;
-                               thread->type = IAX_THREAD_TYPE_DYNAMIC;
-                               ast_mutex_init(&thread->lock);
-                               ast_cond_init(&thread->cond, NULL);
-                               if (ast_pthread_create(&thread->threadid, NULL, iax2_process_thread, thread)) {
-                                       free(thread);
-                                       thread = NULL;
-                               } else {
-                                       /* All went well and the thread is up, so increment our count */
-                                       iaxdynamicthreadcount++;
-                               }
-                       }
-               }
-               AST_LIST_UNLOCK(&dynamic_list);
+       /* If we popped a thread off the idle list, just return it */
+       if (thread)
+               return thread;
+
+       /* Pop the head of the dynamic list off */
+       AST_LIST_LOCK(&dynamic_list);
+       thread = AST_LIST_REMOVE_HEAD(&dynamic_list, list);
+       AST_LIST_UNLOCK(&dynamic_list);
+
+       /* If we popped a thread off the dynamic list, just return it */
+       if (thread)
+               return thread;
+
+       /* If we can't create a new dynamic thread for any reason, return no thread at all */
+       if (iaxdynamicthreadcount >= iaxmaxthreadcount || !(thread = ast_calloc(1, sizeof(*thread))))
+               return NULL;
+
+       /* Set default values */
+       thread->threadnum = ast_atomic_fetchadd_int(&iaxdynamicthreadcount, 1);
+       thread->type = IAX_THREAD_TYPE_DYNAMIC;
+
+       /* Initialize lock and condition */
+       ast_mutex_init(&thread->lock);
+       ast_cond_init(&thread->cond, NULL);
+
+       /* Create thread and send it on it's way */
+       if (ast_pthread_create(&thread->threadid, NULL, iax2_process_thread, thread)) {
+               ast_cond_destroy(&thread->cond);
+               ast_mutex_destroy(&thread->lock);
+               free(thread);
+               thread = NULL;
        }
 
        return thread;
@@ -7696,8 +7701,8 @@ static void *iax2_process_thread(void *data)
                                ast_mutex_unlock(&thread->lock);
                                AST_LIST_LOCK(&dynamic_list);
                                AST_LIST_REMOVE(&dynamic_list, thread, list);
-                               iaxdynamicthreadcount--;
                                AST_LIST_UNLOCK(&dynamic_list);
+                               ast_atomic_dec_and_test(&iaxdynamicthreadcount);
                                break;
                        }
                } else {