[mythtv] r23304 causes serious problem

[Davin McCall]

Hi all,

r23304:
http://svn.mythtv.org/trac/changeset/23304/trunk/mythtv

... causes a serious issue for me. Whenever I try to watch anything - 
live TV, DVD - I get a frozen black screen with "Please wait..." on it. 
One time, it eventually started playing (after ~20 seconds) but it 
generally seems to freeze completely.

Looking at the patch, the only problems I can see is that it is 
accessing some variables (dorun and running) while not always holding a 
lock. This "smells" bad to me. I would think that they should at least 
be declared volatile; I mean, the compiler is allowed to optimize:

71    while (true)
72        {
73            usleep(microsec);
74            if (!dorun)
75                break;
76            emit timeout();
77        }


... by assuming it can load "dorun" into a register and not reload it 
each time it is checked. (not sure but usleep is probably defined to not 
have side effects; depends on exact definition in C library header).

Davin