Re: [Plib-users] invalid OpenGL context problem

[Stephen J B. <sj...@li...>]

Roy Wood said:

> Be a bit more specific about what you mean by waiting though-- do you
> mean that within glIsValidContext(), if glXGetCurrentContext() returns
> NULL, we should literally sleep() for a second or two?  Or were you
> thinking of something subtler?

Well, if your earlier diagnosis is right (I believe you said that
glXGetCurrentContext() was returning NULL because the X server
had not yet actually created the window into which the context
would be rendered)...then waiting for a second or two might well
be enough to kludge around the race condition.

I was thinking of something like:

  for ( int i = 0 ; i < MAX_REDHAT_KLUDGE_DELAY ; i++ )
  {
    if ( glXGetCurrentContext() != NULL )
      return TRUE ;
    else
    {
      fprintf ( stderr, "Crappy RedHat distro...mumble,grumble,complain...\n");
      sleep ( 1 ) ;
    }
  }

  ...print error messages, etc...
  return FALSE ;

...with MAX_REDHAT_KLUDGE_DELAY set to something like 5 - or whatever
it takes to reliably fix the problem.

This won't cause any harm to existing programs and if it works around
the RedHat problem benignly, that's "A Good Thing".

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