Slave backend not reconnecting on socket loss, QTimer/threads related

[Jeff Lu <jll544@…>]

Running trunk r20649, Qt4.4.3:

When my slave backend loses its connection to the master backend, the slave console shows "QObject::startTimer: timers cannot be started from another thread" and the slave never tries to reconnect.

The relevant threads appear to be MainServer and MythSocketThread. When the socket closes, MythSocketThread calls a member function in MainServer that tries to start the masterServerReconnect Qtimer.

But apparently Qt enforces the Qtimer/thread relationship differently on win32 vs. linux (both Qt4.4.3). On linux, the existing code works - timer is started and the slave reconnects. On win32, the error prints, and the timer does not start.

The attached patch corrects this issue on win32 by emitting a signal instead of starting the timer. I've seen other cases of similar Qtimer/thread errors on win32, so I'd be interested in knowing if there are other/better ways to fix this.

[danielk]

I don't like the patch, but this problem needs to be addressed before the 0.22 release.

[danielk]

possible fix

[danielk]

Jeff, can you test the attached patch and let me know if this solves the problem as well?

[Jeff Lu <jll544@…>]

Replying to danielk:

Jeff, can you test the attached patch and let me know if this solves the problem as well?

Yes, the patch does fix this problem. Thanks!

[danielk]

(In [21547]) Fixes #6595. Apply slightly modified version of the patch. This just sends a local message to the event loop to start the reconnect timer instead of calling it directly. Because calling it directly does not always work in Qt4.