From 0f1bdb6b131fffc27baa570b9e8cbc985c4b46f4 Mon Sep 17 00:00:00 2001
From: chenttuuvv <chenttuuvv@yahoo.com>
Date: Wed, 22 Jul 2015 21:10:03 +0800
Subject: [PATCH] threadpool: send signal only when queue is empty
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PR-URL: https://github.com/libuv/libuv/pull/460
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
---
 src/threadpool.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/threadpool.c b/src/threadpool.c
index debaf5ca..dd0abd9a 100644
--- a/src/threadpool.c
+++ b/src/threadpool.c
@@ -101,9 +101,12 @@ static void worker(void* arg) {
 
 
 static void post(QUEUE* q) {
+  int empty_queue;
   uv_mutex_lock(&mutex);
+  empty_queue = QUEUE_EMPTY(&wq);
   QUEUE_INSERT_TAIL(&wq, q);
-  uv_cond_signal(&cond);
+  if (empty_queue)
+    uv_cond_signal(&cond);
   uv_mutex_unlock(&mutex);
 }