unix: speed up uv_async_send()

Don't make a syscall when the handle is already pending. Speeds up the async_pummel benchmark by about 13%.
joyent · Jun 29, 2012 · 4c87666 · 4c87666
1 parent c89df5b
commit 4c87666
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/unix/async.c b/src/unix/async.c
@@ -50,6 +50,9 @@ int uv_async_init(uv_loop_t* loop, uv_async_t* handle, uv_async_cb async_cb) {
 int uv_async_send(uv_async_t* handle) {
   int r;
 
+  if (handle->pending)
+    return 0;
+
   handle->pending = 1; /* XXX needs a memory barrier? */
 
   do