On Mon, May 5, 2014 at 10:06 PM, <exarkun@twistedmatrix.com> wrote:

On 06:49 pm, sank.daniel@gmail.com wrote:

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There's a 3rd party event loop for Twisted that runs on top of Qt (qt4reactor), which would allow Twisted and Qt code to run in the same thread.

Speaking of which, why isn't that thing officially part of twisted? Super useful.

The PyQt team insists that the PyQt license is incompatible with Twisted's license (this is an intentional simplification, you can read more about the issue on PyQt's website if you really care).

Since PySide now exists this is potentially no longer an issue. However, the last thing I heard about using PySide to run the Qt reactor is that it segfaulted sometimes.

So perhaps the reason is that someone needs to do some work to determine if PySide is actually safe to use with the Qt reactor now and, if it is, shuffle some code around.

I think Twisted users just need to start using it, have this doc at hand - https://code.google.com/p/spyderlib/wiki/HowToDebugQtCrash - and register on https://bugreports.qt-project.org/ if there is a trouble (or just mail PySide list).

However, I'm not even sure if the GUI reactors *should* be distributed as part of the main Twisted package. They are already first-class reactors via the plugin system. Independent releases let them track changes in the GUI library they're each concerned with more quickly than they could if they were part of Twisted itself.

Perhaps there are other reasons, like simplicity of packaging or quality of continuous integration testing, that would override those issues and make it worth bringing Qt reactor back into Twisted. Sorting that out is also a task that requires someone interested to step up an do some work, though. :)

The question was - why super useful Qt reactor loop is not a part of Twisted. I think that if it is really useful, it should, -- anatoly t.