Add locking to event_base_loop.

This is harder than it sounds, since we need to make sure to
release the lock around the key call to the kernel (e.g.,
select, epoll_wait, kevent), AND we need to make sure that
none of the fields that are used in that call are touched by
anything that might be running concurrently in another
thread.  I managed to do this pretty well for everything but
poll().  With poll, I needed to introduce a copy of the
event_set structure.

This patch also fixes a bug in win32.c where we called
realloc() instead of mm_realloc().

svn:r1450

1 files changed, 8 insertions, 2 deletions

diff --git a/evport.c b/evport.c
index 55bbe800..32e373c0 100644
--- a/evport.c
+++ b/evport.c
@@ -303,8 +303,14 @@ evport_dispatch(struct event_base *base, struct timeval *tv)
 		}
 	}
 
-	if ((res = port_getn(epdp->ed_port, pevtlist, EVENTS_PER_GETN,
-		    (unsigned int *) &nevents, ts_p)) == -1) {
+	EVBASE_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
+
+	res = port_getn(epdp->ed_port, pevtlist, EVENTS_PER_GETN,
+	    (unsigned int *) &nevents, ts_p);
+
+	EVBASE_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
+
+	if (res == -1) {
 		if (errno == EINTR || errno == EAGAIN) {
 			evsig_process(base);
 			return (0);