[Levent-commits] [Libevent/master] Suspend read/write on bufferevents during hostname lookup

[Nick M. <ni...@us...>]

Author: Nick Mathewson <ni...@to...>
Date: Sat, 20 Feb 2010 12:55:59 -0500
Subject: Suspend read/write on bufferevents during hostname lookup
Commit: db08f640d543bd4ef32ffe1f83c8aeca77bb0ce0

When we're doing a lookup in preparation for doing a connect, we
might have an unconnected socket on hand, and mustn't actually do
any reading or writing with it.
---
 bufferevent-internal.h |    3 +++
 bufferevent_sock.c     |   13 +++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/bufferevent-internal.h b/bufferevent-internal.h
index ad1f844..5be964f 100644
--- a/bufferevent-internal.h
+++ b/bufferevent-internal.h
@@ -53,6 +53,9 @@ extern "C" {
 #define BEV_SUSPEND_BW 0x02
 /* On a base bufferevent: when we have emptied the group's bandwidth bucket. */
 #define BEV_SUSPEND_BW_GROUP 0x04
+/* On a socket bufferevent: can't do any operations while we're waiting for
+ * name lookup to finish. */
+#define BEV_SUSPEND_LOOKUP 0x08
 
 struct bufferevent_rate_limit_group {
 	/** List of all members in the group */
diff --git a/bufferevent_sock.c b/bufferevent_sock.c
index 006c8ec..df048de 100644
--- a/bufferevent_sock.c
+++ b/bufferevent_sock.c
@@ -417,6 +417,9 @@ bufferevent_connect_getaddrinfo_cb(int result, struct evutil_addrinfo *ai,
 	int r;
 	BEV_LOCK(bev);
 
+	bufferevent_unsuspend_write(bev, BEV_SUSPEND_LOOKUP);
+	bufferevent_unsuspend_read(bev, BEV_SUSPEND_LOOKUP);
+
 	if (result != 0) {
 		/* XXX Communicate the error somehow. */
 		_bufferevent_run_eventcb(bev, BEV_EVENT_ERROR);
@@ -452,14 +455,20 @@ bufferevent_socket_connect_hostname(struct bufferevent *bev,
 	hint.ai_protocol = IPPROTO_TCP;
 	hint.ai_socktype = SOCK_STREAM;
 
+	bufferevent_suspend_write(bev, BEV_SUSPEND_LOOKUP);
+	bufferevent_suspend_read(bev, BEV_SUSPEND_LOOKUP);
+
 	bufferevent_incref(bev);
 	err = evutil_getaddrinfo_async(evdns_base, hostname, portbuf,
 	    &hint, bufferevent_connect_getaddrinfo_cb, bev);
 
-	if (err == 0)
+	if (err == 0) {
 		return 0;
-	else
+	} else {
+		bufferevent_unsuspend_write(bev, BEV_SUSPEND_LOOKUP);
+		bufferevent_unsuspend_read(bev, BEV_SUSPEND_LOOKUP);
 		return -1;
+	}
 }
 
 /*
-- 
1.6.3