From: Willy Tarreau <w@1wt.eu>
Date: Wed, 7 Jan 2009 19:10:39 +0000 (+0100)
Subject: [MEDIUM] stream_sock: factor out the return path in case of no-writes
X-Git-Tag: v1.3.16-rc1~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4d9b1dee9f15406c87d73181a7cf8b177b68452b;p=thirdparty%2Fhaproxy.git

[MEDIUM] stream_sock: factor out the return path in case of no-writes

Previously, we wrote nothing only if the buffer was empty. Now with
send_max, we can also write nothing because we are not allowed to send
anything due to send_max.

The code starts to look like spaghetti. It needs to be rearranged a
lot before merging the splice patches.
---

diff --git a/src/stream_sock.c b/src/stream_sock.c
index d10faa8f1f..7b684f4e31 100644
--- a/src/stream_sock.c
+++ b/src/stream_sock.c
@@ -358,13 +358,12 @@ int stream_sock_write(int fd) {
 			}
 
 			/* Funny, we were called to write something but there wasn't
-			 * anything. Theorically we cannot get there, but just in case,
-			 * let's disable the write event and pretend we never came there.
+			 * anything. We can get there, for example if we were woken up
+			 * on a write event to finish the splice, but the send_max is 0
+			 * so we cannot write anything from the buffer. Let's disable
+			 * the write event and pretend we never came there.
 			 */
-			si->flags |= SI_FL_WAIT_DATA;
-			EV_FD_CLR(fd, DIR_WR);
-			b->wex = TICK_ETERNITY;
-			goto out_wakeup;
+			goto write_nothing;
 		}
 
 #ifndef MSG_NOSIGNAL
@@ -409,6 +408,7 @@ int stream_sock_write(int fd) {
 			if (!b->l && !b->splice_len) {
 				b->flags |= BF_EMPTY;
 
+			write_nothing:
 				/* Maybe we just wrote the last chunk and need to close ? */
 				if ((b->flags & (BF_SHUTW|BF_EMPTY|BF_HIJACK|BF_WRITE_ENA|BF_SHUTR)) == (BF_EMPTY|BF_WRITE_ENA|BF_SHUTR)) {
 					if (si->state == SI_ST_EST) {
@@ -418,7 +418,11 @@ int stream_sock_write(int fd) {
 					}
 				}
 
-				si->flags |= SI_FL_WAIT_DATA;
+				/* we may either get there when the buffer is empty or when
+				 * we refrain from sending due to send_max reached.
+				 */
+				if (!b->l && !b->splice_len)
+					si->flags |= SI_FL_WAIT_DATA;
 				EV_FD_CLR(fd, DIR_WR);
 				b->wex = TICK_ETERNITY;
 				goto out_wakeup;