thread scheduling at mutex unlock

[Andrew Snow]

> But I think that it is not "fair" that at re-lock former
> owner gets the lock immediately and the thread that waited on it for
> longer time doesn't get a chance.

I believe this is what yield() is for.  Before attempting a re-lock you 
should call yield() to allow other threads a chance to run.

(Side note: On FreeBSD, I believe only high priority threads will run 
when you yield().  As a workaround, I think you have to lower the 
thread's priority before yield() and then raise it again afterwards.)


- Andrew