Author: remy.maucherat(a)jboss.com Date: 2014-02-17 05:33:49 -0500 (Mon, 17 Feb 2014) New Revision: 2366 Modified: branches/7.4.x/src/main/java/org/apache/tomcat/websocket/WsRemoteEndpointImplBase.java Log: Port patch to avoid deadlock closing during a write. Modified: branches/7.4.x/src/main/java/org/apache/tomcat/websocket/WsRemoteEndpointImplBase.java =================================================================== --- branches/7.4.x/src/main/java/org/apache/tomcat/websocket/WsRemoteEndpointImplBase.java 2014-02-14 13:12:02 UTC (rev 2365) +++ branches/7.4.x/src/main/java/org/apache/tomcat/websocket/WsRemoteEndpointImplBase.java 2014-02-17 10:33:49 UTC (rev 2366) @@ -250,6 +250,7 @@ MessagePart mp = new MessagePart(opCode, payload, last, handler, this); + boolean doWrite = false; synchronized (messagePartLock) { if (Constants.OPCODE_CLOSE == mp.getOpCode()) { try { @@ -260,30 +261,38 @@ } if (messagePartInProgress) { // When a control message is sent while another message is being - // the control message is queued. Chances are the subsequent - // data message part will end up queued while the control - // message is sent. The logic in this class (state machine, - // EndMessageHanlder, TextMessageSendHandler) ensures that there - // will only ever be one data message part in the queue. There - // could be multiple control messages in the queue. + // sent, the control message is queued. Chances are the + // subsequent data message part will end up queued while the + // control message is sent. The logic in this class (state + // machine, EndMessageHandler, TextMessageSendHandler) ensures + // that there will only ever be one data message part in the + // queue. There could be multiple control messages in the queue. // Add it to the queue messagePartQueue.add(mp); } else { messagePartInProgress = true; - writeMessagePart(mp); + doWrite = true; } } + if (doWrite) { + // Actual write has to be outside sync block to avoid possible + // deadlock between messagePartLock and writeLock in + // o.a.coyote.http11.upgrade.AbstractServletOutputStream + writeMessagePart(mp); + } } void endMessage(SendHandler handler, SendResult result) { + boolean doWrite = false; + MessagePart mpNext = null; synchronized (messagePartLock) { fragmented = nextFragmented; text = nextText; - MessagePart mpNext = messagePartQueue.poll(); + mpNext = messagePartQueue.poll(); if (mpNext == null) { messagePartInProgress = false; } else if (!closed){ @@ -291,9 +300,15 @@ // sending a fragmented message closing the endpoint. If this // happens, clearly there is no point trying to send the rest of // the message. - writeMessagePart(mpNext); + doWrite = true; } } + if (doWrite) { + // Actual write has to be outside sync block to avoid possible + // deadlock between messagePartLock and writeLock in + // o.a.coyote.http11.upgrade.AbstractServletOutputStream + writeMessagePart(mpNext); + } wsSession.updateLastActive();