> where did this go?
Based on the discussions on this thread so far, and on
https://github.com/libuv/libuv/pull/790
I'd like to propose the following diff:
Index: rthread.h
===================================================================
RCS file: /cvs/src/lib/librthread/rthread.h,v
retrieving revision 1.56
diff -r1.56 rthread.h
144c144,145
- int sofar;
+ int in;
+ int out;
Index: rthread_barrier.c
===================================================================
RCS file: /cvs/src/lib/librthread/rthread_barrier.c,v
retrieving revision 1.2
diff -r1.2 rthread_barrier.c
71a72
+ int rc;
76a78,80
+ if (rc = pthread_mutex_lock(&(*barrier)->mutex))
+ return (rc);
+
79c83,84
- if (b->sofar > 0)
+ if (b->out > 0 || b->in > 0) {
+ pthread_mutex_unlock(&b->mutex);
80a86
+ }
82a89
+ pthread_mutex_unlock(&b->mutex);
106,108c113,116
- _rthread_debug(6, "sofar: %d, threshold: %d\n", b->sofar, b->threshold);
- if (++b->sofar == b->threshold) {
- b->sofar = 0;
+ _rthread_debug(6, "in: %d, threshold: %d\n", b->in, b->threshold);
+ if (++b->in == b->threshold) {
+ b->out = b->in - 1;
+ b->in = 0;
110c118
- if ((rc = pthread_cond_broadcast(&b->cond)))
+ if ((rc = pthread_cond_signal(&b->cond)))
120a129,131
+ b->out--; /* mark thread exit */
+ if ((rc = pthread_cond_signal(&b->cond)))
+ goto err;
This is pretty much identical to what Paul suggested, but with a blocking call
to pthread_mutex_lock in _destroy,
as I really think this is the semantics programmers expect, and I it looks to
me like this is what freeBSD does,
although I don't really understand their code completely.
I also changed pthread_cond_broadcast to pthread_cond_signal, as pointed out by
bnoordhuis in the linked thread
on github, it's more efficient to avoid waking up threads that will immediately
start blocking on a mutex again.
I apologise in advance if the diff appears strange, I don't really know how to
get cvs to do what I want.
