Recursion depth exceeded exception

[jhargis]

2016-04-18 22:44:46-0700 [WProtocol,0,192.168.1.202] Unhandled Error
    Traceback (most recent call last):
      File "/Users/j/SOURCE/w/qt5reactor.py", line 305, in doIteration
        self.qApp.processEvents(QEventLoop.AllEvents, delay * 1000)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 291, in _iterate
        self.doIteration(delay, fromqt)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 305, in doIteration
        self.qApp.processEvents(QEventLoop.AllEvents, delay * 1000)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 186, in write
        log.callWithLogger(w, _write)
    --- <exception caught here> ---
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 101, in callWithLogger
        return callWithContext({"system": lp}, func, *args, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 84, in callWithContext
        return context.call({ILogContext: newCtx}, func, *args, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/context.py", line 118, in callWithContext
        return self.currentContext().callWithContext(ctx, func, *args, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/context.py", line 81, in callWithContext
        return func(*args,**kw)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 185, in _write
        self.reactor._iterate(fromqt=True)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 290, in _iterate
        self.runUntilCurrent()
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/internet/base.py", line 827, in runUntilCurrent
        log.deferr()
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 132, in err
        msg(failure=_stuff, why=_why, isError=1, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/threadable.py", line 53, in sync
        return function(self, *args, **kwargs)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 282, in msg
        _publishNew(self._publishPublisher, actualEventDict, textFromEventDict)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_legacy.py", line 154, in publishToNewObserver
        observer(eventDict)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_observer.py", line 136, in __call__
        errorLogger = self._errorLoggerForObserver(brokenObserver)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_observer.py", line 156, in _errorLoggerForObserver
        if obs is not observer
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_observer.py", line 81, in __init__
        self.log = Logger(observer=self)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_logger.py", line 52, in __init__
        namespace = self._namespaceFromCallingContext()
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_logger.py", line 32, in _namespaceFromCallingContext
        return currentframe(2).f_globals["__name__"]
    exceptions.RuntimeError: maximum recursion depth exceeded

2016-04-18 22:44:46-0700 [WProtocol,0,192.168.1.202] Unhandled Error
    Traceback (most recent call last):
      File "/Users/j/SOURCE/w/qt5reactor.py", line 305, in doIteration
        self.qApp.processEvents(QEventLoop.AllEvents, delay * 1000)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 291, in _iterate
        self.doIteration(delay, fromqt)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 305, in doIteration
        self.qApp.processEvents(QEventLoop.AllEvents, delay * 1000)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 165, in read
        log.callWithLogger(w, _read)
    --- <exception caught here> ---
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 101, in callWithLogger
        return callWithContext({"system": lp}, func, *args, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 84, in callWithContext
        return context.call({ILogContext: newCtx}, func, *args, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/context.py", line 118, in callWithContext
        return self.currentContext().callWithContext(ctx, func, *args, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/context.py", line 81, in callWithContext
        return func(*args,**kw)
      File "/Users/j/SOURCE/w/qt5reactor.py", line 157, in _read
        log.err()
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 132, in err
        msg(failure=_stuff, why=_why, isError=1, **kw)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/threadable.py", line 53, in sync
        return function(self, *args, **kwargs)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/python/log.py", line 282, in msg
        _publishNew(self._publishPublisher, actualEventDict, textFromEventDict)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_legacy.py", line 154, in publishToNewObserver
        observer(eventDict)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_observer.py", line 136, in __call__
        errorLogger = self._errorLoggerForObserver(brokenObserver)
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_observer.py", line 156, in _errorLoggerForObserver
        if obs is not observer
      File "/Users/j/.virtualenvs/w/lib/python2.7/site-packages/twisted/logger/_observer.py", line 81, in __init__
        self.log = Logger(observer=self)
    exceptions.RuntimeError: maximum recursion depth exceeded

^C2016-04-18 22:44:48-0700 [-] Received SIGINT, shutting down.
2016-04-18 22:44:48-0700 [twisted.internet.protocol.Factory] (TCP Port 4337 Closed)
2016-04-18 22:44:48-0700 [-] Stopping factory <twisted.internet.protocol.Factory instance at 0x10da9bfc8>

This recursion exception is thrown while chunking a large file and sending 16k blocks as messages through AMP. It happens very erratically. I'll try to put together some test code that exposes it. May be difficult since it seems to be so unpredictable.

using Twisted 16.1.1 , Python 2.7.11 , PyQt 5.5.1

[altendky]

altendky@a52c0d0

You might try my branch to see if it helps. I had similar issues before that commit. I haven't gotten a response over in #11 so my stuff might be bad in other ways but it did seem like an oversight to not actually exercise the fromqt parameter.

[crwood]

Have either of you been able to reproduce this issue reliably, by any chance? I would like to fix it, if possible, but have not yet run into it on my end (and am not sure how to isolate without a good test case).

@jhargis Did you ever end up trying @altendky's branch?

[jhargis]

@crwood No, sorry. I've abandoned it all together. I mentioned it to @glyph in the #twisted irc channel and he took a quick peek and seemed to understand the problem right away but it was beyond me as I don't have intimate working knowledge of the Twisted core. IIRC he mentioned that some technique being used was flatly incorrect. I'd strongly recommend tapping him for insight.

Sorry can't be more helpful on this.

[glyph]

Is anyone interested in this problem at PyCon this year?

[crwood]

Unfortunately, I will not be. :(