Index: channels/chan_iax2.c
===================================================================
--- channels/chan_iax2.c	(revision 128639)
+++ channels/chan_iax2.c	(working copy)
@@ -727,7 +727,8 @@
 	time_t checktime;
 	ast_mutex_t lock;
 	ast_cond_t cond;
-	unsigned int ready_for_signal:1;
+	ast_mutex_t init_lock;
+	ast_cond_t init_cond;
 	/*! if this thread is processing a full frame,
 	  some information about that frame will be stored
 	  here, so we can avoid dispatching any more full
@@ -925,6 +926,9 @@
 				thread->type = IAX_TYPE_DYNAMIC;
 				ast_mutex_init(&thread->lock);
 				ast_cond_init(&thread->cond, NULL);
+				ast_mutex_init(&thread->init_lock);
+				ast_cond_init(&thread->init_cond, NULL);
+				ast_mutex_lock(&thread->init_lock);
 				pthread_attr_init(&attr);
 				pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);	
 				if (ast_pthread_create(&thread->threadid, &attr, iax2_process_thread, thread)) {
@@ -935,8 +939,10 @@
 					iaxdynamicthreadcount++;
 					
 					/* Wait for the thread to be ready before returning it to the caller */
-					while (!thread->ready_for_signal)
-						usleep(1);
+					ast_cond_wait(&thread->init_cond, &thread->init_lock);
+
+					/* Done with init_lock */
+					ast_mutex_unlock(&thread->init_lock);
 				}
 			}
 		}
@@ -8537,6 +8543,8 @@
 	struct iax2_thread *thread = data;
 	ast_mutex_destroy(&thread->lock);
 	ast_cond_destroy(&thread->cond);
+	ast_mutex_destroy(&thread->init_lock);
+	ast_cond_destroy(&thread->init_cond);
 	free(thread);
 	ast_atomic_dec_and_test(&iaxactivethreadcount);
 }
@@ -8547,6 +8555,7 @@
 	struct timeval tv;
 	struct timespec ts;
 	int put_into_idle = 0;
+	int first_time = 1;
 
 	ast_atomic_fetchadd_int(&iaxactivethreadcount,1);
 	pthread_cleanup_push(iax2_process_thread_cleanup, data);
@@ -8555,8 +8564,11 @@
 		ast_mutex_lock(&thread->lock);
 
 		/* Flag that we're ready to accept signals */
-		thread->ready_for_signal = 1;
-		
+		if (first_time) {
+			signal_condition(&thread->init_lock, &thread->init_cond);
+			first_time = 0;
+		}
+
 		/* Put into idle list if applicable */
 		if (put_into_idle)
 			insert_idle_thread(thread);