From 81f38d6f5772a71eaa78d65d14c49c70f8fab6ab Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Mon, 13 Apr 2015 17:11:11 +0200
Subject: [PATCH] MEDIUM: applet: add basic support for an applet run queue

This will be needed so that we can schedule applets out of the streams.
For now nothing calls the queue yet.
---
 Makefile               |  2 +-
 include/proto/applet.h | 13 +++++++++++++
 include/types/applet.h |  1 +
 src/applet.c           | 21 +++++++++++++++++++++
 4 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 src/applet.c

diff --git a/Makefile b/Makefile
index 917f023f6..3c9ee24f5 100644
--- a/Makefile
+++ b/Makefile
@@ -703,7 +703,7 @@ OBJS = src/haproxy.o src/sessionhash.o src/base64.o src/protocol.o \
        src/arg.o src/stick_table.o src/proto_uxst.o src/connection.o \
        src/proto_http.o src/raw_sock.o src/appsession.o src/backend.o \
        src/lb_chash.o src/lb_fwlc.o src/lb_fwrr.o src/lb_map.o src/lb_fas.o \
-       src/stream_interface.o src/dumpstats.o src/proto_tcp.o \
+       src/stream_interface.o src/dumpstats.o src/proto_tcp.o src/applet.o \
        src/session.o src/stream.o src/hdr_idx.o src/ev_select.o src/signal.o \
        src/acl.o src/sample.o src/memory.o src/freq_ctr.o src/auth.o \
        src/compression.o src/payload.o src/hash.o src/pattern.o src/map.o \
diff --git a/include/proto/applet.h b/include/proto/applet.h
index fd458d492..4e43bbe5b 100644
--- a/include/proto/applet.h
+++ b/include/proto/applet.h
@@ -25,9 +25,12 @@
 #include <stdlib.h>
 
 #include <common/config.h>
+#include <common/mini-clist.h>
 #include <types/applet.h>
 #include <proto/connection.h>
 
+extern struct list applet_runq;
+
 /* Initializes all required fields for a new appctx. Note that it does the
  * minimum acceptable initialization for an appctx. This means only the
  * 3 integer states st0, st1, st2 are zeroed.
@@ -51,6 +54,7 @@ static inline struct appctx *appctx_new(struct applet *applet)
 		appctx->obj_type = OBJ_TYPE_APPCTX;
 		appctx->applet = applet;
 		appctx_init(appctx);
+		LIST_INIT(&appctx->runq);
 	}
 	return appctx;
 }
@@ -60,9 +64,18 @@ static inline struct appctx *appctx_new(struct applet *applet)
  */
 static inline void appctx_free(struct appctx *appctx)
 {
+	if (!LIST_ISEMPTY(&appctx->runq))
+		LIST_DEL(&appctx->runq);
 	pool_free2(pool2_connection, appctx);
 }
 
+/* wakes up an applet when conditions have changed */
+static inline void appctx_wakeup(struct appctx *appctx)
+{
+	if (LIST_ISEMPTY(&appctx->runq))
+		LIST_ADDQ(&applet_runq, &appctx->runq);
+}
+
 #endif /* _PROTO_APPLET_H */
 
 /*
diff --git a/include/types/applet.h b/include/types/applet.h
index 5e989f6bc..c2db0ec3e 100644
--- a/include/types/applet.h
+++ b/include/types/applet.h
@@ -40,6 +40,7 @@ struct applet {
 
 /* Context of a running applet. */
 struct appctx {
+	struct list runq;          /* chaining in the applet run queue */
 	enum obj_type obj_type;    /* OBJ_TYPE_APPCTX */
 	/* 3 unused bytes here */
 	unsigned int st0;          /* CLI state for stats, session state for peers */
diff --git a/src/applet.c b/src/applet.c
new file mode 100644
index 000000000..ca3ead1b3
--- /dev/null
+++ b/src/applet.c
@@ -0,0 +1,21 @@
+/*
+ * Functions managing applets
+ *
+ * Copyright 2000-2015 Willy Tarreau <w@1wt.eu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <common/config.h>
+#include <common/mini-clist.h>
+#include <proto/applet.h>
+
+
+struct list applet_runq = LIST_HEAD_INIT(applet_runq);