From fb0162d7697e71f466ac9f9af501decfa0062a88 Mon Sep 17 00:00:00 2001
From: yuqing <yuqing@yongche.com>
Date: Wed, 8 Jun 2016 18:30:14 +0800
Subject: [PATCH] check g_free_queue.head == NULL before free_queue_realloc()

---
 HISTORY               |  3 ++-
 src/fast_task_queue.c | 38 ++++++++++++++++++++++++--------------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/HISTORY b/HISTORY
index 16bac36..3bce3fd 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,10 +1,11 @@
 
-Version 1.28  2016-06-06
+Version 1.28  2016-06-08
   * id generator support extra bits
   * change inet_aton to inet_pton
   * connect by ip and connection pool support ipv6
   * id generator in php extension support multi instance
   * add function http_parse_url_params
+  * check g_free_queue.head == NULL before free_queue_realloc()
 
 Version 1.27  2016-04-15
   * add function fd_set_cloexec
diff --git a/src/fast_task_queue.c b/src/fast_task_queue.c
index 273de6a..6d1ba64 100644
--- a/src/fast_task_queue.c
+++ b/src/fast_task_queue.c
@@ -410,6 +410,8 @@ static int free_queue_realloc()
 struct fast_task_info *free_queue_pop()
 {
     struct fast_task_info *pTask;
+    int i;
+
 	if ((pTask=task_queue_pop(&g_free_queue)) != NULL)
     {
         return pTask;
@@ -420,26 +422,34 @@ struct fast_task_info *free_queue_pop()
         return NULL;
     }
 
-	pthread_mutex_lock(&g_free_queue.lock);
-    if (g_free_queue.alloc_connections >= g_free_queue.max_connections)
+    for (i=0; i<10; i++)
     {
-        if (g_free_queue.head == NULL)
+        pthread_mutex_lock(&g_free_queue.lock);
+        if (g_free_queue.alloc_connections >= g_free_queue.max_connections)
         {
-            pthread_mutex_unlock(&g_free_queue.lock);
-            return NULL;
+            if (g_free_queue.head == NULL)
+            {
+                pthread_mutex_unlock(&g_free_queue.lock);
+                return NULL;
+            }
         }
-    }
-    else
-    {
-        if (free_queue_realloc() != 0)
+        else
         {
-            pthread_mutex_unlock(&g_free_queue.lock);
-            return NULL;
+            if (g_free_queue.head == NULL && free_queue_realloc() != 0)
+            {
+                pthread_mutex_unlock(&g_free_queue.lock);
+                return NULL;
+            }
         }
-    }
-	pthread_mutex_unlock(&g_free_queue.lock);
+        pthread_mutex_unlock(&g_free_queue.lock);
 
-    return task_queue_pop(&g_free_queue);
+        if ((pTask=task_queue_pop(&g_free_queue)) != NULL)
+        {
+            return pTask;
+        }
+    }
+
+    return NULL;
 }
 
 static int _realloc_buffer(struct fast_task_info *pTask, const int new_size,