From: ufo2243 <ufo2243@gmail.com>
Date: Fri, 12 Sep 2014 03:51:59 +0000 (+0800)
Subject: make bufferevent_getwatermark api more robust
X-Git-Tag: release-2.1.5-beta~34^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a21e5108c2e689ae2ea8176d84f9978719e8ec36;p=libevent

make bufferevent_getwatermark api more robust
---

diff --git a/bufferevent.c b/bufferevent.c
index 588461a3..2e6be144 100644
--- a/bufferevent.c
+++ b/bufferevent.c
@@ -615,25 +615,30 @@ bufferevent_setwatermark(struct bufferevent *bufev, short events,
 	BEV_UNLOCK(bufev);
 }
 
-void
+int
 bufferevent_getwatermark(struct bufferevent *bufev, short events,
     size_t *lowmark, size_t *highmark)
 {
-	BEV_LOCK(bufev);
 	if (events == EV_WRITE) {
+		BEV_LOCK(bufev);
 		if (lowmark)
 			*lowmark = bufev->wm_write.low;
 		if (highmark)
 			*highmark = bufev->wm_write.high;
+		BEV_UNLOCK(bufev);
+		return 0;
 	}
 
 	if (events == EV_READ) {
+		BEV_LOCK(bufev);
 		if (lowmark)
 			*lowmark = bufev->wm_read.low;
 		if (highmark)
 			*highmark = bufev->wm_read.high;
+		BEV_UNLOCK(bufev);
+		return 0;
 	}
-	BEV_UNLOCK(bufev);
+	return -1;
 }
 
 int
diff --git a/include/event2/bufferevent.h b/include/event2/bufferevent.h
index 46203b04..a97030ef 100644
--- a/include/event2/bufferevent.h
+++ b/include/event2/bufferevent.h
@@ -535,8 +535,9 @@ void bufferevent_setwatermark(struct bufferevent *bufev, short events,
     size_t lowmark, size_t highmark);
 
 /**
-  Retrieves the watermarks for read or write events. Result is undefined if
-  events contains both EV_READ and EV_WRITE.
+  Retrieves the watermarks for read or write events.
+  Returns non-zero if events contains not only EV_READ or EV_WRITE.
+  Returns zero if events equal EV_READ or EV_WRITE
 
   @param bufev the bufferevent to be examined
   @param events EV_READ or EV_WRITE
@@ -544,7 +545,7 @@ void bufferevent_setwatermark(struct bufferevent *bufev, short events,
   @param highmark receives the high watermark if not NULL
 */
 EVENT2_EXPORT_SYMBOL
-void bufferevent_getwatermark(struct bufferevent *bufev, short events,
+int bufferevent_getwatermark(struct bufferevent *bufev, short events,
     size_t *lowmark, size_t *highmark);
 
 /**
diff --git a/test/regress_bufferevent.c b/test/regress_bufferevent.c
index 4ec2dccf..669efd8a 100644
--- a/test/regress_bufferevent.c
+++ b/test/regress_bufferevent.c
@@ -287,6 +287,9 @@ test_bufferevent_watermarks_impl(int use_pair)
 	tt_int_op(low, ==, 100);
 	tt_int_op(high, ==, 2000);
 
+	int r = bufferevent_getwatermark(bev1, EV_WRITE | EV_READ, &low, &high);
+	tt_int_op(r, !=, 0);
+
 	bufferevent_write(bev1, buffer, sizeof(buffer));
 
 	event_dispatch();