mythfrontend playback hangs

[tomimo@…]

The latest trunk version #25218 seems to have problems with its current decoder locking scheme. It seems that I can pretty realiably hang the frontend every time by trying to playback a single (specific) recorded program via diskless MythFrontend node. The problem does exist in two different diskless nodes that are used for playback in this household (ie. even though the hardware's are 2.8Ghz/Athlon/32-bit and Athlon X2/3800Mhz, they are on slow side performance wise).

The symptom is always the following message looping eternally in the frontend log:

2010-06-30 10:19:41.431 NVP(0), Warning: Waited 100ms for decoder to unpause

To me it looks like that the following code in NuppelVideoPlayer?.cpp might fail, in case the condition wake up signal is sent before the waiting thread has had the chance to call the condition.wait(). If that happens, the waiting thread will never break from the while loop.

void NuppelVideoPlayer::UnpauseDecoder?(void) {

decoderPauseLock.lock();

if (QThread::currentThread() == (QThread*)decoderThread) {

decoderPaused = false; decoderThreadUnpause.wakeAll(); decoderPauseLock.unlock(); return;

}

unpauseDecoder = true; while (!decoderThreadUnpause.wait(&decoderPauseLock, 100))

VERBOSE(VB_IMPORTANT, LOC_WARN + "Waited 100ms for decoder to unpause");

unpauseDecoder = false; decoderPauseLock.unlock();

}

[tomimo@…]

MythFrontend logfile

[tomimo@…]

Patch: This patch seems to fix the most often seen hang in this household

[markk]

This issue was fixed in r25266 and r25258.