Project: Tomcat
Bug 52770 Potential Bug or Inconsistency in NioBlockingSelector.java
Reported: 2012-02-25 15:04:31 | Status: resolved fixed

This is Ken Cheung, a Computer Science M.Phil. student. I observed some code clones in Tomcat and found inconsistent code: /tomcat/trunk/java/org/apache/tomcat/util/net/NioBlockingSelector.java 103 try { 104 if ( att.getWriteLatch()==null || att.getWriteLatch().getCount()==0) att.startWriteLatch(1); 105 poller.add(att,SelectionKey.OP_WRITE,reference); 106 att.awaitWriteLatch(writeTimeout,TimeUnit.MILLISECONDS); 107 }catch (InterruptedException ignore) { 108 Thread.interrupted(); 109 } 110 if ( att.getWriteLatch()!=null && att.getWriteLatch().getCount()> 0) { 111 //we got interrupted, but we haven't received notification from the poller. 112 keycount = 0; 113 }else { 114 //latch countdown has happened 115 keycount = 1; 116 att.resetWriteLatch(); 117 } 118 119 if (writeTimeout > 0 && (keycount == 0)) 120 timedout = (System.currentTimeMillis() - time) >= writeTimeout; /tomcat/trunk/java/org/apache/tomcat/util/net/NioBlockingSelector.java 164 try { 165 if ( att.getReadLatch()==null || att.getReadLatch().getCount()==0) att.startReadLatch(1); 166 poller.add(att,SelectionKey.OP_READ, reference); 167 if (readTimeout < 0) { 168 att.awaitReadLatch(Long.MAX_VALUE, TimeUnit.MILLISECONDS); 169 } else { 170 att.awaitReadLatch(readTimeout, TimeUnit.MILLISECONDS); 171 } 172 }catch (InterruptedException ignore) { 173 Thread.interrupted(); 174 } 175 if ( att.getReadLatch()!=null && att.getReadLatch().getCount()> 0) { 176 //we got interrupted, but we haven't received notification from the poller. 177 keycount = 0; 178 }else { 179 //latch countdown has happened 180 keycount = 1; 181 att.resetReadLatch(); 182 } 183 if (readTimeout >= 0 && (keycount == 0)) 184 timedout = (System.currentTimeMillis() - time) >= readTimeout; Quick description of the inconsistency Two code snippets are very similar code, but as you see, the first code does not check "if (readTimeout < 0)" while the second code has the checker. We thought it could be a potential bug or inconsistency. Hope this helps.

Files changed in fix:
java/org/apache/tomcat/util/net/NioBlockingSelector.java