[execnet-dev] Internal errors calling channel.send

[Shead, Timothy]

On Aug 18, 2011, at 2:05 AM, holger krekel wrote:

>> Sure 'nuff, here's a test case that always hangs in the same spot:
>> 
>> def stress_server(channel):
>>  for request in channel:
>>    channel.send(request)
>> 
>> gateway = execnet.makegateway("popen//python=jython")
>> channel = gateway.remote_exec(stress_server)
>> 
>> for size in range(31):
>>  sys.stderr.write("Sending string length %d\n" % 2**size)
>>  original = "a" * (2**size)
>>  channel.send(original)
>>  response = channel.receive()
>>  self.assertEqual(original, response)


> Hi Timothy,
> 
> i presume this problem does not occur with CPython or PyPy versions, does it

Correct, this problem only manifests when using CPython <--> Jython.  If I test CPython <--> CPython, I'm able to pass huge amounts of data back-and-forth without problem.

> I wonder if Jython maybe has some problem with socket-sending/receiving code
> or if there are race conditions between the receiving and sending thread
> (Jython has free threading - the other python implementations do not).
> 
> Not sure i can help much but could you send the jython and java versions
> you are using?

Sure, this is Jython running on an OSX 10.6 workstation, installed with MacPorts:

Jython 2.5.2 (Release_2_5_2:7206, Mar 2 2011, 23:12:06) 
[Java HotSpot(TM) 64-Bit Server VM (Apple Inc.)] on java1.6.0_24

Cheers,
Tim

Timothy M. Shead
Sandia National Laboratories
1461, Scalable Analysis and Visualization