[vdr] Re: vdr-1.3.17: thread issues with vdr-xine and vdr-osdteletext

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

C.Y.M wrote:
> Klaus Schmidinger wrote:
>
> > ...
> > > OK, this has been a problem (even with the previous thread safe 
> > > patches I was using), but when I try to use streamdev in suspend mode 
> > > with Klaus' new threading patch, it appears that VDR is creating TWO 
> > > threads.
> > >
> > >
> > > Dec 19 12:33:07 poseidon vdr[26763]: switching to channel 10300
> > > Dec 19 12:33:07 poseidon vdr[30554]: transfer thread started 
> > > (pid=30554, tid=1900553)
> > > Dec 19 12:33:07 poseidon vdr[30555]: transfer thread started 
> > > (pid=30555, tid=1916938)
> > > Dec 19 12:33:07 poseidon vdr[30556]: receiver on device 1 thread 
> > > started (pid=30556, tid=1933323)
> > > Dec 19 12:33:07 poseidon vdr[30557]: TS buffer on device 1 thread 
> > > started (pid=30557, tid=1949708)
> > > Dec 19 12:33:10 poseidon vdr[26779]: ERROR: thread 1933323 won't end 
> > > (waited 3 seconds) - canceling it...
> > > Dec 19 12:33:10 poseidon vdr[30555]: transfer thread ended 
> > > (pid=30555, tid=1916938)
> > > Dec 19 12:33:10 poseidon vdr[26779]: buffer stats: 0 (0%) used
> >
> >
> > That's odd. Does streamdev mess around with "Transfer Mode"?
> I probably am not the right person to answer that question, but I know 
> that if you manually tune vdr to a channel and then try to stream, it 
> works fine.  But, if I am on a different channel and use the suspend 
> option to tell vdr to switch to the channel that I want it to stream, 
> then there seems to be some kind of race condition that is causing two 
> threads to be created.  I wish I could offer you more details.
>
> Thanks,
> C.Y.M.
I know that there's still a possible race condition in cDevice::AttachReceiver().
You could try this (untested, just an idea):

--- device.c    2004/12/17 13:51:44     1.63
+++ device.c    2004/12/19 21:56:29
@@ -990,6 +990,7 @@
      esyslog("ERROR: device %d has no lock, can't attach receiver!", CardIndex() + 1);
      return false;
      }
+  LOCK_THREAD;
   for (int i = 0; i < MAXRECEIVERS; i++) {
       if (!receiver[i]) {
          for (int n = 0; n < MAXRECEIVEPIDS; n++) {
@@ -1000,10 +1001,8 @@
                 }
              }
          Receiver->Activate(true);
-         Lock();
          Receiver->device = this;
          receiver[i] = Receiver;
-         Unlock();
          Start();
          return true;
          }
@@ -1017,19 +1016,19 @@
   if (!Receiver || Receiver->device != this)
      return;
   bool receiversLeft = false;
+  Lock();
   for (int i = 0; i < MAXRECEIVERS; i++) {
       if (receiver[i] == Receiver) {
          Receiver->Activate(false);
-         Lock();
          receiver[i] = NULL;
          Receiver->device = NULL;
-         Unlock();
          for (int n = 0; n < MAXRECEIVEPIDS; n++)
              DelPid(Receiver->pids[n]);
          }
       else if (receiver[i])
          receiversLeft = true;
       }
+  Unlock();
   if (!receiversLeft) {
      active = false;
      Cancel(3);


The line numbers are probably way off, since I've already made several
other changes, but it should be fairly easy to make thes changes
manually.

Klaus