From: Nick Mathewson <nickm@torproject.org>
Date: Tue, 24 Dec 2013 16:30:06 +0000 (-0500)
Subject: Minor optimizations on bufferevent_trigger options
X-Git-Tag: release-2.1.4-alpha~60
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a3172a415b709d1df76b27ee86c738e4d8b6f87b;p=libevent

Minor optimizations on bufferevent_trigger options

By making BEV_TRIG_DEFER_CALLBACKS equal to BEV_OPT_DEFER_CALLBACKS,
and BEV_TRIG_IGNORE_WATERMARKS disjoint from BEV_OPT_*, we can save a
few operations in bufferevent_run_*, which is critical-path.
---

diff --git a/bufferevent.c b/bufferevent.c
index 19413369..588461a3 100644
--- a/bufferevent.c
+++ b/bufferevent.c
@@ -226,8 +226,7 @@ bufferevent_run_readcb_(struct bufferevent *bufev, int options)
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	if (bufev->readcb == NULL)
 		return;
-	if ((p->options & BEV_OPT_DEFER_CALLBACKS) ||
-	    (options & BEV_TRIG_DEFER_CALLBACKS)) {
+	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 		p->readcb_pending = 1;
 		SCHEDULE_DEFERRED(p);
 	} else {
@@ -243,8 +242,7 @@ bufferevent_run_writecb_(struct bufferevent *bufev, int options)
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	if (bufev->writecb == NULL)
 		return;
-	if ((p->options & BEV_OPT_DEFER_CALLBACKS) ||
-	    (options & BEV_TRIG_DEFER_CALLBACKS)) {
+	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 		p->writecb_pending = 1;
 		SCHEDULE_DEFERRED(p);
 	} else {
@@ -252,11 +250,16 @@ bufferevent_run_writecb_(struct bufferevent *bufev, int options)
 	}
 }
 
+#define BEV_TRIG_ALL_OPTS (			\
+		BEV_TRIG_IGNORE_WATERMARKS|	\
+		BEV_TRIG_DEFER_CALLBACKS	\
+	)
+
 void
 bufferevent_trigger(struct bufferevent *bufev, short iotype, int options)
 {
 	bufferevent_incref_and_lock_(bufev);
-	bufferevent_trigger_nolock_(bufev, iotype, options);
+	bufferevent_trigger_nolock_(bufev, iotype, options&BEV_TRIG_ALL_OPTS);
 	bufferevent_decref_and_unlock_(bufev);
 }
 
@@ -268,8 +271,7 @@ bufferevent_run_eventcb_(struct bufferevent *bufev, short what, int options)
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	if (bufev->errorcb == NULL)
 		return;
-	if ((p->options & BEV_OPT_DEFER_CALLBACKS) ||
-	    (options & BEV_TRIG_DEFER_CALLBACKS)) {
+	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
 		p->eventcb_pending |= what;
 		p->errno_pending = EVUTIL_SOCKET_ERROR();
 		SCHEDULE_DEFERRED(p);
@@ -282,7 +284,7 @@ void
 bufferevent_trigger_event(struct bufferevent *bufev, short what, int options)
 {
 	bufferevent_incref_and_lock_(bufev);
-	bufferevent_run_eventcb_(bufev, what, options);
+	bufferevent_run_eventcb_(bufev, what, options&BEV_TRIG_ALL_OPTS);
 	bufferevent_decref_and_unlock_(bufev);
 }
 
diff --git a/include/event2/bufferevent.h b/include/event2/bufferevent.h
index 1026ca9e..07bfd19d 100644
--- a/include/event2/bufferevent.h
+++ b/include/event2/bufferevent.h
@@ -564,10 +564,13 @@ int bufferevent_flush(struct bufferevent *bufev,
 */
 enum bufferevent_trigger_options {
 	/** trigger the callback regardless of the watermarks */
-	BEV_TRIG_IGNORE_WATERMARKS = (1<<0),
+	BEV_TRIG_IGNORE_WATERMARKS = (1<<16),
 
 	/** defer even if the callbacks are not */
-	BEV_TRIG_DEFER_CALLBACKS = (1<<1),
+	BEV_TRIG_DEFER_CALLBACKS = BEV_OPT_DEFER_CALLBACKS,
+
+	/* (Note: for internal reasons, these need to be disjoint from
+	 * bufferevent_options, except when they mean the same thing. */
 };
 
 /**