From 17671de22626f84eb86338dc9a5120b5d8d55ab2 Mon Sep 17 00:00:00 2001
From: beiwei30 <ian.luo@gmail.com>
Date: Wed, 23 May 2018 16:41:32 +0800
Subject: [PATCH 1/2]     #677: There is a potential deadlock in
 DubboProtocol#getSharedClient

---
 .../com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java b/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java
index 4e8b971328d..1fab24caa6d 100644
--- a/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java
+++ b/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java
@@ -373,7 +373,7 @@ private ExchangeClient getSharedClient(URL url) {
                 referenceClientMap.remove(key);
             }
         }
-        synchronized (key.intern()) {
+        synchronized ((key + ".lock").intern()) {
             ExchangeClient exchangeClient = initClient(url);
             client = new ReferenceCountExchangeClient(exchangeClient, ghostClientMap);
             referenceClientMap.put(key, client);

From 6a8424f67819f2b55cc36db255841433e7a23190 Mon Sep 17 00:00:00 2001
From: beiwei30 <ian.luo@gmail.com>
Date: Thu, 24 May 2018 10:15:38 +0800
Subject: [PATCH 2/2]     #677: There is a potential deadlock in
 DubboProtocol#getSharedClient

---
 .../dubbo/rpc/protocol/dubbo/DubboProtocol.java        | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java b/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java
index 1fab24caa6d..017e4a93df3 100644
--- a/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java
+++ b/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/com/alibaba/dubbo/rpc/protocol/dubbo/DubboProtocol.java
@@ -65,6 +65,7 @@ public class DubboProtocol extends AbstractProtocol {
     private final Map<String, ExchangeServer> serverMap = new ConcurrentHashMap<String, ExchangeServer>(); // <host:port,Exchanger>
     private final Map<String, ReferenceCountExchangeClient> referenceClientMap = new ConcurrentHashMap<String, ReferenceCountExchangeClient>(); // <host:port,Exchanger>
     private final ConcurrentMap<String, LazyConnectExchangeClient> ghostClientMap = new ConcurrentHashMap<String, LazyConnectExchangeClient>();
+    private final ConcurrentMap<String, Object> locks = new ConcurrentHashMap<String, Object>();
     private final Set<String> optimizers = new ConcurrentHashSet<String>();
     //consumer side export a stub service for dispatching event
     //servicekey-stubmethods
@@ -373,11 +374,18 @@ private ExchangeClient getSharedClient(URL url) {
                 referenceClientMap.remove(key);
             }
         }
-        synchronized ((key + ".lock").intern()) {
+
+        locks.putIfAbsent(key, new Object());
+        synchronized (locks.get(key)) {
+            if (referenceClientMap.containsKey(key)) {
+                return referenceClientMap.get(key);
+            }
+
             ExchangeClient exchangeClient = initClient(url);
             client = new ReferenceCountExchangeClient(exchangeClient, ghostClientMap);
             referenceClientMap.put(key, client);
             ghostClientMap.remove(key);
+            locks.remove(key);
             return client;
         }
     }