[DIRMINA-942] Infinite loop flushing to broken pipe

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.7
• Fix Version/s: 2.0.8
• Assignee: Unassigned
• Reporter: Joshua Warner
• Created: 16/Apr/13 14:54
• Updated: 08/Sep/14 15:26
• Resolved: 08/Sep/14 15:26

Description

Every once in a while (in production only, of course), a couple of threads will go off into the weeds, consuming 100% CPU, and never come back. They're sitting in an infinite loop that looks something like this:

• We're chugging merrily along in the main processing loop (AbstractPollingIoProcessor.java:1070)
• Decide to flush the single session in flushingSessions (AbstractPollingIoProcessor.java:773, :1129)
• According to "SessionState state = getState(session)", the session is OPENED, which I think is a lie, and perhaps the root of the problem.
• Enter "flushNow" (AbstractPollingIoProcessor.java:821, :789, :1129)
• Begin processing a queued message (AbstractPollingIoProcessor.java:861, :789, :1129)
• Try to write out the message in writeBuffer (AbstractPollingIoProcessor.java:931, :861, :789, :1129)
• Catch an IOException ("Broken pipe") in writeBuffer (AbstractPollingIoProcessor.java:935, :861, :789, :1129), call "session.close(true)"
• Next time around the loop at (AbstractPollingIoProcessor.java:1070), the session is put back in flushingSessions, because apparently the session is still writable (liar!) (AbstractPollingIoProcessor.java:671, :653, :1124)
• Repeat, Ad Infinitum!

The suggested fix, courtesy Emmanuel Lécharny, is:
add this line in the AbstractPollingIoProcessor
class, line 927 :

            try {
                localWrittenBytes = write(session, buf, length);
            } catch (IOException ioe) {
                // We have had an issue while trying to send data to the
                // peer : let's close the session.
                buf.free();
                session.close(true);

                destroy(session);  // <<<<<<<<<<<<<<<<<---- This line

                return 0;
            }