Re: [PATCH] libports: fix the thread counts in case the thread creation fails

[Neal H. Walfield]

At Sun, 10 Nov 2013 11:54:20 +0100,
Samuel Thibault wrote:
> 
> Neal H. Walfield, le Sun 10 Nov 2013 11:38:04 +0100, a écrit :
> > At Sat, 9 Nov 2013 18:21:51 +0100,
> > Samuel Thibault wrote:
> > > > +             pthread_spin_lock (&lock);
> > > > +             totalthreads--;
> > > > +             nreqthreads--;
> > > > +             pthread_spin_unlock (&lock);
> > 
> > It might be a good idea use atomic operations instead of the spin lock
> > (which is what the spin lock is using behind the scenes anyways).
> 
> It may not be possible: further down there is a decision taken depending
> on totalthreads/nreqthreads becoming 1, and thus you need a spinlock to
> make that coherent with the ++/--.

Too bad.  Perhaps combining the quantities into a single word as
follows would work:

  atomic.add(threads, 1<<16 | 1)

This has the further advantage of reducing the number of atomic
operations.

Neal