new file mode 100644
--- /dev/null
+++ b/src/event/ngx_event_mutex.c
@@ -0,0 +1,14 @@
+
+spinlock_max depend on CPU number and mutex type.
+    1 CPU               1
+    ngx_malloc_mutex    1000 ?
+
+
+int ngx_event_mutex_trylock(ngx_mutex_t *mtx)
+{
+    for(i = mtx->spinlock_max; i; i--)
+        if (trylock(mtx->lock))
+            return 1;
+
+    return 0;
+}