From 86009b5439a898fa00cc27e675bb7834576be70a Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Thu, 7 Jun 2012 17:51:41 +0200
Subject: [PATCH] add more instance state handling code

---
 service.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++-----------
 service.h |   2 ++
 2 files changed, 96 insertions(+), 20 deletions(-)

diff --git a/service.c b/service.c
index f50daa7..360810e 100644
--- a/service.c
+++ b/service.c
@@ -6,33 +6,83 @@ struct avl_tree services;
 static struct blob_buf b;
 
 static void
-service_instance_update(struct vlist_tree *tree, struct vlist_node *node_new,
-			struct vlist_node *node_old)
+start_instance(struct service_instance *in)
 {
-	struct service_instance *in_o = NULL, *in_n = NULL;
+	in->restart = false;
+}
 
-	if (node_old)
-		in_o = container_of(node_old, struct service_instance, node);
+static void
+instance_timeout(struct uloop_timeout *t)
+{
+	struct service_instance *in;
 
-	if (node_new)
-		in_n = container_of(node_new, struct service_instance, node);
+	in = container_of(t, struct service_instance, timeout);
+	kill(in->proc.pid, SIGKILL);
+	uloop_process_delete(&in->proc);
+	in->proc.cb(&in->proc, -1);
+}
 
-	do {
-		if (!in_o || !in_n)
-			break;
+static void
+instance_exit(struct uloop_process *p, int ret)
+{
+	struct service_instance *in;
+
+	in = container_of(p, struct service_instance, proc);
+	uloop_timeout_cancel(&in->timeout);
+	if (in->restart)
+		start_instance(in);
+}
 
-		/* full match, nothing to do */
+static void
+stop_instance(struct service_instance *in, bool restart)
+{
+	if (!in->proc.pending)
 		return;
-	} while (0);
 
-	if (in_o) {
-		/* kill old process */
-		free(in_o);
-	}
+	kill(in->proc.pid, SIGTERM);
+}
 
-	if (in_n) {
-		/* start new process */
-	}
+static bool
+instance_config_changed(struct service_instance *in, struct service_instance *in_new)
+{
+	int len = blob_pad_len(in->config);
+
+	if (len != blob_pad_len(in_new->config))
+		return true;
+
+	if (memcmp(in->config, in_new->config, blob_pad_len(in->config)) != 0)
+		return true;
+
+	return false;
+}
+
+static bool
+update_instance(struct service_instance *in, struct service_instance *in_new)
+{
+	bool changed = instance_config_changed(in, in_new);
+
+	in->config = in_new->config;
+	if (!changed)
+		return false;
+
+	stop_instance(in, true);
+	return true;
+}
+
+static void
+free_instance(struct service_instance *in)
+{
+	uloop_process_delete(&in->proc);
+	uloop_timeout_cancel(&in->timeout);
+	free(in);
+}
+
+static void
+init_instance(struct service_instance *in, struct blob_attr *config)
+{
+	in->config = config;
+	in->timeout.cb = instance_timeout;
+	in->proc.cb = instance_exit;
 }
 
 static void
@@ -48,10 +98,33 @@ service_instance_add(struct service *s, struct blob_attr *attr)
 	if (!in)
 		return;
 
-	in->config = attr;
+	init_instance(in, attr);
 	vlist_add(&s->instances, &in->node, (void *) name);
 }
 
+static void
+service_instance_update(struct vlist_tree *tree, struct vlist_node *node_new,
+			struct vlist_node *node_old)
+{
+	struct service_instance *in_o = NULL, *in_n = NULL;
+
+	if (node_old)
+		in_o = container_of(node_old, struct service_instance, node);
+
+	if (node_new)
+		in_n = container_of(node_new, struct service_instance, node);
+
+	if (in_o && in_n) {
+		update_instance(in_o, in_n);
+		free_instance(in_n);
+	} else if (in_o) {
+		stop_instance(in_o, false);
+		free_instance(in_o);
+	} else if (in_n) {
+		start_instance(in_n);
+	}
+}
+
 static struct service *
 service_alloc(const char *name)
 {
@@ -59,6 +132,7 @@ service_alloc(const char *name)
 
 	s = calloc(1, sizeof(*s));
 	vlist_init(&s->instances, avl_strcmp, service_instance_update);
+	s->instances.keep_old = true;
 
 	return s;
 }
diff --git a/service.h b/service.h
index c2afdae..96175c4 100644
--- a/service.h
+++ b/service.h
@@ -15,7 +15,9 @@ struct service_instance {
 	struct vlist_node node;
 	const char *name;
 
+	bool restart;
 	struct blob_attr *config;
 	struct uloop_process proc;
+	struct uloop_timeout timeout;
 };
 
-- 
2.11.0