[NET-3] [net][PATCH] TelnetInputStream.read sometimes hangs if reader thread is disabled

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed

Environment

Operating System: Windows XP
Platform: PC

• Bugzilla Id: 38688
• Assignee: Unassigned
• Reporter: Rob Hasselbaum
• Created: 17/Feb/06 07:47
• Updated: 20/Sep/07 05:24
• Resolved: 20/Sep/07 05:24

Description

I'm trying to use TelnetClient with the reader thread disabled because I don't
want socket timeouts to fire during planned periods of inactivity (COM-1554).

But when the thread is disabled, I'm finding that TelnetInputStream.read
occassionally hangs when I try to read output from the server.
The problem appears to be the first while loop in __processChar, which looks
like this:

synchronized (__queue)
{
while (__bytesAvailable >= __queue.length - 1)
{
if(__threaded)
{
__queue.notify();
try

{ __queue.wait(); }

catch (InterruptedException e)

{ throw e; }

}
...
}

If you get into this loop and the threaded flag is false, you are stuck
forever. That's what's happening in my case. If I suspend the thread, I can
see that (_bytesAvailable) is 2048 and (_queue.length -
1) is also 2048, so it's an infinite loop.

I'm not sure what triggers this, but it seems to happen most often when there
is a pause in server output or a pause before I initiate the next read.