[jboss-jira] [JBoss JIRA] Resolved: (JGRP-613) Access to NAKACK#rebroadcast_digest field needs a lock

Access to NAKACK#rebroadcast_digest field needs a lock ------------------------------------------------------ Key: JGRP-613 URL: http://jira.jboss.com/jira/browse/JGRP-613 Project: JGroups Issue Type: Bug Affects Versions: 2.6 Reporter: Vladimir Blagojevic Assigned To: Bela Ban Priority: Minor Fix For: 2.6 It seems that rebroadcast_digest field of NAKACK is accessed by multiple threads which step over each other leading to a consequences below. This is very hard to reproduce and I have seen it only a few times so far. ------------------------------------------------------- GMS: address is 127.0.0.1:2528 ------------------------------------------------------- 11141 [INFO][main] ConcurrentStateTransferTest: - Thread for channel 127.0.0.1:2528[A] started 15250 [INFO][A] ConcurrentStateTransferTest: - channel.getState at A127.0.0.1:2518 returned false 15297 [INFO][Multiplexer,udp,127.0.0.1:2520] ConcurrentStateTransferTest: - -- [#A (127.0.0.1:2520)]: received 127.0.0.1:2518 15297 [INFO][Multiplexer,udp,127.0.0.1:2524] ConcurrentStateTransferTest: - -- [#A (127.0.0.1:2524)]: received 127.0.0.1:2518 15297 [INFO][Multiplexer,udp,127.0.0.1:2518] ConcurrentStateTransferTest: - -- [#A (127.0.0.1:2518)]: received 127.0.0.1:2518 15297 [INFO][Multiplexer,udp,127.0.0.1:2528] ConcurrentStateTransferTest: - -- [#A (127.0.0.1:2528)]: received 127.0.0.1:2518 15328 [ERROR][OOB,udp,127.0.0.1:2520] UDP: - failed handling incoming message java.lang.NullPointerException at org.jgroups.protocols.pbcast.NAKACK.rebroadcastMessages(NAKACK.java:1036) at org.jgroups.protocols.pbcast.NAKACK.down(NAKACK.java:620) at org.jgroups.protocols.UNICAST.down(UNICAST.java:434) at org.jgroups.protocols.pbcast.STABLE.down(STABLE.java:317) at org.jgroups.protocols.pbcast.GMS.down(GMS.java:813) at org.jgroups.protocols.FC.down(FC.java:370) at org.jgroups.protocols.FRAG2.down(FRAG2.java:175) at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER.down(STREAMING_STATE_TRANSFER.java:318) at org.jgroups.protocols.pbcast.FLUSH.handleFlushReconcile(FLUSH.java:455) at org.jgroups.protocols.pbcast.FLUSH.up(FLUSH.java:337) at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER.up(STREAMING_STATE_TRANSFER.java:258) at org.jgroups.protocols.FRAG2.up(FRAG2.java:205) at org.jgroups.protocols.FC.up(FC.java:408) at org.jgroups.protocols.pbcast.GMS.up(GMS.java:742) at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:234) at org.jgroups.protocols.UNICAST.up(UNICAST.java:264) at org.jgroups.protocols.pbcast.NAKACK.handleMessage(NAKACK.java:798) at org.jgroups.protocols.pbcast.NAKACK.up(NAKACK.java:662) at org.jgroups.protocols.VERIFY_SUSPECT.up(VERIFY_SUSPECT.java:167) at org.jgroups.protocols.FD.up(FD.java:322) at org.jgroups.protocols.FD_SOCK.up(FD_SOCK.java:308) at org.jgroups.protocols.MERGE2.up(MERGE2.java:145) at org.jgroups.protocols.Discovery.up(Discovery.java:250) at org.jgroups.protocols.TP$IncomingPacket.handleMyMessage(TP.java:1512) at org.jgroups.protocols.TP$IncomingPacket.run(TP.java:1461) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675) at java.lang.Thread.run(Thread.java:595)