From 2db99441c85fdf1e7d468bc02b085d9e1b95704c Mon Sep 17 00:00:00 2001
From: Victor Vieux <victor.vieux@dotcloud.com>
Date: Wed, 17 Jul 2013 20:39:36 +0000
Subject: [PATCH] prevent any kind of operation simultaneously

---
 server.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/server.go b/server.go
index 48a64aa8c8..de20ff65c7 100644
--- a/server.go
+++ b/server.go
@@ -477,6 +477,9 @@ func (srv *Server) poolAdd(kind, key string) error {
 	if _, exists := srv.pullingPool[key]; exists {
 		return fmt.Errorf("pull %s is already in progress", key)
 	}
+	if _, exists := srv.pushingPool[key]; exists {
+		return fmt.Errorf("push %s is already in progress", key)
+	}
 
 	switch kind {
 	case "pull":