commit 89f7ef295da763b9c6388be1c81439cb0b566b2d
author Willy Tarreau <w@1wt.eu> Sat Sep 05 20:57:35 2009 +0200
committer Willy Tarreau <w@1wt.eu> Wed Sep 23 23:52:14 2009 +0200
tree 944fad09fe91fa9f5fd20279f75bfab5975674de
parent 2e1dd3d21350ad5eef7f688eee0c75e140430190

[MINOR] stream_interface: add SI_FL_DONT_WAKE flag

We had to add a new stream_interface flag : SI_FL_DONT_WAKE. This flag
is used to indicate that a stream interface is being updated and that
no wake up should be sent to its owner. This will be required for tasks
embedded into stream interfaces. Otherwise, we could have the
owner task send wakeups to itself during status updates, thus
preventing the state from converging. As long as a stream_interface's
status is being monitored and adjusted, there is no reason to wake it
up again, as we know its changes will be seen and considered.

include/types/stream_interface.h

diff --git a/include/types/stream_interface.h b/include/types/stream_interface.h
index c9b0e55..7e99722 100644
--- a/include/types/stream_interface.h
+++ b/include/types/stream_interface.h
@@ -2,7 +2,7 @@
   include/types/stream_interface.h
   This file describes the stream_interface struct and associated constants.
 
-  Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
+  Copyright (C) 2000-2009 Willy Tarreau - w@1wt.eu
 
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
@@ -68,6 +68,7 @@
 	SI_FL_WAIT_ROOM  = 0x0004,  /* waiting for space to store incoming data */
 	SI_FL_WAIT_DATA  = 0x0008,  /* waiting for more data to send */
 	SI_FL_CAP_SPLTCP = 0x0010,  /* splicing possible from/to TCP */
+	SI_FL_DONT_WAKE  = 0x0020,  /* resync in progress, don't wake up */
 };
 
 #define SI_FL_CAP_SPLICE (SI_FL_CAP_SPLTCP)

src/session.c

diff --git a/src/session.c b/src/session.c
index 38c1453..d085f16 100644
--- a/src/session.c
+++ b/src/session.c
@@ -636,6 +636,12 @@
 	rqf_last = s->req->flags;
 	rpf_last = s->rep->flags;
 
+	/* we don't want the stream interface functions to recursively wake us up */
+	if (s->req->prod->owner == t)
+		s->req->prod->flags |= SI_FL_DONT_WAKE;
+	if (s->req->cons->owner == t)
+		s->req->cons->flags |= SI_FL_DONT_WAKE;
+
 	/* 1a: Check for low level timeouts if needed. We just set a flag on
 	 * stream interfaces when their timeouts have expired.
 	 */
@@ -1128,6 +1134,10 @@
 	if ((s->rep->flags ^ rpf_last) & BF_MASK_STATIC)
 		goto resync_response;
 
+	/* we're interested in getting wakeups again */
+	s->req->prod->flags &= ~SI_FL_DONT_WAKE;
+	s->req->cons->flags &= ~SI_FL_DONT_WAKE;
+
 	/* This is needed only when debugging is enabled, to indicate
 	 * client-side or server-side close. Please note that in the unlikely
 	 * event where both sides would close at once, the sequence is reported

src/stream_sock.c

diff --git a/src/stream_sock.c b/src/stream_sock.c
index 72c8607..ed2af62 100644
--- a/src/stream_sock.c
+++ b/src/stream_sock.c
@@ -1087,7 +1087,8 @@
 		   ((ob->flags & BF_OUT_EMPTY) && !ob->to_forward) ||
 		   si->state != SI_ST_EST)) {
 	out_wakeup:
-		task_wakeup(si->owner, TASK_WOKEN_IO);
+		if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
+			task_wakeup(si->owner, TASK_WOKEN_IO);
 	}
 }