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, 6 insertions, 0 deletions

diff --git a/epoll.c b/epoll.c
index b6fa28ed..a01e501f 100644
--- a/epoll.c
+++ b/epoll.c
@@ -51,6 +51,8 @@
 
 #include "event-internal.h"
 #include "evsignal-internal.h"
+#include "event2/thread.h"
+#include "evthread-internal.h"
 #include "log-internal.h"
 #include "evmap-internal.h"
 
@@ -148,8 +150,12 @@ epoll_dispatch(struct event_base *base, struct timeval *tv)
 		timeout = MAX_EPOLL_TIMEOUT_MSEC;
 	}
 
+	EVBASE_RELEASE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
+
 	res = epoll_wait(epollop->epfd, events, epollop->nevents, timeout);
 
+	EVBASE_ACQUIRE_LOCK(base, EVTHREAD_WRITE, th_base_lock);
+
 	if (res == -1) {
 		if (errno != EINTR) {
 			event_warn("epoll_wait");