[mythtv] Mythfrontend hang with CVS

[Leo Weppelman]

On Wed, Jun 09, 2004 at 02:26:34PM +0200, Leo Weppelman wrote:
> On Tue, Jun 08, 2004 at 06:11:24PM -0500, Stacey Son wrote:
> > OK, Looking at the 0.15 release code the loop was introduced by a change 
> > in MythCDROM::openDevice():
> > 
> > In 0.15 release:
> > 
> >   MythCDROM::openDevice()
> >   {
> >      if (MythMediaDevice::openDevice())
> >      {
> >         ...
> >        if (m_AllowEject)
> >            ioctl(m_DeviceHandle, CDROM_LOCKDOOR, 0);
> > 
> > was changed to:
> > 
> >   MythCDROM::openDevice()
> >   {
> >      if (MythMediaDevice::openDevice())
> >      {
> >         ...
> >        if (m_AllowEject)
> >            unlock();
> > 
> > Your patch should fix the looping problem but I don't see right off why 
> > it is not sensing media changes now.    You could try changing the above 
> > back and see if that, for some reason, fixes this.
> 
> Yes, putting back de ioctl makes myht see the media changes again... I
> haven't figured out why yet.

I think I've got it! The ioct() -> unlock() change caused the following
calltree on opening the device:

MythCDROM::openDevice()
  MythMediaDevice::openDevice()) {
      MythCDROMLinux::unlock {
          m_DeviceHandle, CDROM_LOCKDOOR, 0)
          MythMediaDevice::unlock {
             MythMediaDevice::closeDevice()   <----- !!!!!
          }
      }
  }
}

Notice that open reports that it successfully opened the device while by
calling unlock() it indirectly closed the device right after opening it :-(

Leo.