[jcifs] Possible deadlock?

Michael B Allen mba2000 at ioplex.com
Sat Aug 19 15:36:06 GMT 2006

I doubt this is a deadlock. A deadlock is when two threads are waiting
for each other to complete but can't because they're trying to access
the same resource. To determine if a deadlock has occured, wait for
your program to hang and then invoke a thread dump (Ctrl-\ on UNIX,
don't recall what the trigger is on Windows). If threads are deadlocked
the thread dump will indicate so.

It is not uncommon for a host to be unresponsive such that the client
will hang. For example, if there is no reply to an initial SYN packet
it takes about 1 min 15 sec to timeout. But everything should eventually
timeout somewhere and continue.

Finally, for efficient crawling there is a cocktail of properties to
set. You can find them by searching the list archives. Otherwise, if
you're just testing then be patient or fix the broken host.


On Sat, 19 Aug 2006 09:54:16 -0400
Jake Goulding <goulding at vivisimo.com> wrote:

> Hey all,
> I am using jCIFS do do a crawl of a bunch of local computers (via the  
> C$ share). Basically it is just a test to push it to the limit.
> However, I seem to consistently get a thread (or a few) stuck on a  
> particular host. The host is not constant between runs, but if there  
> are a few threads, they all are stuck on the same host.
> This time I have jSwat connected to it, so I can actually figure out  
> what is happening where.
> It is currently stuck in TransactNamedPipeInputStream.read, line 71
> This line has a lock.wait() call, and while I'm not particularly well- 
> versed with how jCIFS does its locking, but I cannot find a notify  
> call that corresponds to it.
> Any help is appreciated, and I plan on just leaving the debugger  
> connected until I figure this out :-)
> Thanks!
> -- 
> Software Engineer
> goulding at vivisimo.com
> Viví simo [Search Done Right___]
> 1710 Murray Avenue
> Pittsburgh, PA 15217 USA
> tel: +1.412.422.2499 x105
> fax: +1.412.422.2495
> vivisimo.com      clusty.com

Michael B Allen
PHP Active Directory SSO

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