Guard write rejection checks #258

Protect rejection checks agains visibility and race issues in case a disconnect is right now in progress while a command gets written.
redis · May 31, 2016 · 513729d · 513729d
1 parent 8971f88
commit 513729d
Showing 1 changed file with 15 additions and 14 deletions.
diff --git a/src/main/java/com/lambdaworks/redis/protocol/CommandHandler.java b/src/main/java/com/lambdaworks/redis/protocol/CommandHandler.java
@@ -211,27 +211,28 @@ public <T> RedisCommand<K, V, T> write(RedisCommand<K, V, T> command) {
 
         checkArgument(command != null, "command must not be null");
 
-        if (lifecycleState == LifecycleState.CLOSED) {
-            throw new RedisException("Connection is closed");
-        }
-
-        if (commandBuffer.size() + queue.size() >= clientOptions.getRequestQueueSize()) {
-            throw new RedisException("Request queue size exceeded: " + clientOptions.getRequestQueueSize()
-                    + ". Commands are not accepted until the queue size drops.");
-        }
-
-        if ((channel == null || !isConnected()) && !clientOptions.isAutoReconnect()) {
-            throw new RedisException(
-                    "Connection is in a disconnected state and reconnect is disabled. Commands are not accepted.");
-        }
-
         try {
             /**
              * This lock causes safety for connection activation and somehow netty gets more stable and predictable performance
              * than without a lock and all threads are hammering towards writeAndFlush.
              */
 
             writeLock.lock();
+
+            if (lifecycleState == LifecycleState.CLOSED) {
+                throw new RedisException("Connection is closed");
+            }
+
+            if (commandBuffer.size() + queue.size() >= clientOptions.getRequestQueueSize()) {
+                throw new RedisException("Request queue size exceeded: " + clientOptions.getRequestQueueSize()
+                        + ". Commands are not accepted until the queue size drops.");
+            }
+
+            if ((channel == null || !isConnected()) && !clientOptions.isAutoReconnect()) {
+                throw new RedisException(
+                        "Connection is in a disconnected state and reconnect is disabled. Commands are not accepted.");
+            }
+
             Channel channel = this.channel;
             if (autoFlushCommands) {