beremiz

Runtime: work around 1s delay added when using twisted reactor's callLater.
wxPython4
2022-10-05, Edouard Tisserant
c3aae4c95bc1
Parents 369c3edc1a65
Children f08b59f7c00a
Runtime: work around 1s delay added when using twisted reactor's callLater.

Since wxPython4, using wxReactor from non-main thread was producing
exceptions in wxWidget's C++ code. Then reactor.run() was called from
main thread, and runtime's worker was delegating calls to reactor
with callLater(0, callable).

While this worked perfectly with wxReactor, it did introduce an unexplained
1 second delay to each worker call when using nomal linux reactors
(i.e. without wxPython). As a workaround reactor runs in a thread when using
twisted without wxPython
1 files changed, 39 insertions(+), 13 deletions(-)
  • +39 -13
    Beremiz_service.py
    • --- a/Beremiz_service.py Wed Sep 14 15:24:33 2022 +0200
    +++ b/Beremiz_service.py Wed Oct 05 16:10:17 2022 +0200
    @@ -423,7 +423,12 @@
    if havewx:
    from twisted.internet import wxreactor
    wxreactor.install()
    - from twisted.internet import reactor
    + from twisted.internet import reactor
    + reactor.registerWxApp(app)
    + else:
    + # from twisted.internet import pollreactor
    + # pollreactor.install()
    + from twisted.internet import reactor
    havetwisted = True
    except ImportError:
    @@ -432,11 +437,6 @@
    pyruntimevars = {}
    -if havetwisted:
    - if havewx:
    - reactor.registerWxApp(app)
    -
    -
    if havewx:
    wx_eval_lock = Semaphore(0)
    @@ -578,26 +578,50 @@
    runtime.GetPLCObjectSingleton().AutoLoad(autostart)
    -if havetwisted or havewx:
    +if havetwisted and havewx:
    - waker_func = wx.CallAfter if havewx else partial(reactor.callLater,0)
    + waker_func = wx.CallAfter
    # This orders ui loop to signal when ready on Stdout
    waker_func(print,"UI thread started successfully.")
    - # worker that copes with wx and (wx)reactor
    + # interleaved worker copes with wxreactor by delegating all asynchronous
    + # calls to wx's mainloop
    runtime.MainWorker.interleave(waker_func, FirstWorkerJob)
    try:
    - if havetwisted:
    - reactor.run(installSignalHandlers=False)
    - else:
    - app.MainLoop
    + reactor.run(installSignalHandlers=False)
    except KeyboardInterrupt:
    pass
    runtime.MainWorker.stop()
    +elif havewx:
    +
    + try:
    + app.MainLoop
    + except KeyboardInterrupt:
    + pass
    +
    +elif havetwisted:
    +
    + ui_thread_started = Lock()
    + ui_thread_started.acquire()
    +
    + reactor.callLater(0, ui_thread_started.release)
    +
    + ui_thread = Thread(
    + target=partial(reactor.run, installSignalHandlers=False),
    + name="UIThread")
    + ui_thread.start()
    +
    + ui_thread_started.acquire()
    + print("UI thread started successfully.")
    + try:
    + # blocking worker loop
    + runtime.MainWorker.runloop(FirstWorkerJob)
    + except KeyboardInterrupt:
    + pass
    else:
    try:
    # blocking worker loop
    @@ -618,6 +642,8 @@
    if havetwisted:
    reactor.stop()
    + if not havewx:
    + ui_thread.join()
    elif havewx:
    app.ExitMainLoop()