title: What is weblogic.socket.Muxer?
body: <p>Does any of you understand what weblogic.socket.Muxer is used for in WebLogic 8.1?</p>
  
  <p>Often in thread dumps I see stack traces similar to this:</p>
  
  <pre><code>"ExecuteThread: '0' for queue: 'weblogic.socket.Muxer'" id=20 idx=0x68 tid=26709 prio=5 alive, in native, blocked, daemon
      -- Blocked trying to get lock: java/lang/String@0x2b673d373c50[fat lock]
      at jrockit/vm/Threads.waitForUnblockSignal()V(Native Method)
      at jrockit/vm/Locks.fatLockBlockOrSpin(Locks.java:1675)[optimized]
      at jrockit/vm/Locks.lockFat(Locks.java:1776)[optimized]
      at jrockit/vm/Locks.monitorEnterSecondStageHard(Locks.java:1312)[optimized]
      at jrockit/vm/Locks.monitorEnterSecondStage(Locks.java:1259)[optimized]
      at jrockit/vm/Locks.monitorEnter(Locks.java:2439)[optimized]
      at weblogic/socket/EPollSocketMuxer.processSockets(EPollSocketMuxer.java:153)
      at weblogic/socket/SocketReaderRequest.run(SocketReaderRequest.java:29)
      at weblogic/socket/SocketReaderRequest.execute(SocketReaderRequest.java:42)
      at weblogic/kernel/ExecuteThread.execute(ExecuteThread.java:145)
      at weblogic/kernel/ExecuteThread.run(ExecuteThread.java:117)
      at jrockit/vm/RNI.c2java(JJJJJ)V(Native Method)
      -- end of trace
  </code></pre>
  
  <p>It's not that I have any problems with that, it is just intresting to understand:</p>
  
  <p>1) what is it doing? <br>
  2) can it affect any performance?</p>