From a088c116f0a520c2b6e1fea4bebc288a97359913 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Thu, 22 Nov 2018 09:56:30 +0200
Subject: [PATCH] node: added support for pause/resume and restart node
 instances

---
 include/villas/common.h    |  3 +-
 include/villas/node.h      | 18 ++++++++++++
 include/villas/node_type.h | 24 +++++++++++++++
 lib/node.c                 | 60 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 104 insertions(+), 1 deletion(-)

diff --git a/include/villas/common.h b/include/villas/common.h
index 73ba53ba0..3aa4c2d21 100644
--- a/include/villas/common.h
+++ b/include/villas/common.h
@@ -40,7 +40,8 @@ enum state {
 	STATE_UNLOADED		= 5, /* alias for STATE_STARTED used by struct plugin */
 	STATE_CLOSED		= 5, /* alias for STATE_STARTED used by struct io */
 	STATE_PENDING_CONNECT	= 6,
-	STATE_CONNECTED		= 7
+	STATE_CONNECTED		= 7,
+	STATE_PAUSED		= 9
 };
 
 /** Callback to destroy list elements.
diff --git a/include/villas/node.h b/include/villas/node.h
index 27aace9fa..a0673f6af 100644
--- a/include/villas/node.h
+++ b/include/villas/node.h
@@ -125,6 +125,24 @@ int node_start(struct node *n);
  */
 int node_stop(struct node *n);
 
+/** Pauses operation of a node.
+ *
+ * @see node_type::close
+ */
+int node_pause(struct node *n);
+
+/** Resumes operation of a node.
+ *
+ * @see node_type::close
+ */
+int node_resume(struct node *n);
+
+/** Restarts operation of a node.
+ *
+ * @see node_type::close
+ */
+int node_restart(struct node *n);
+
 /** Destroy node by freeing dynamically allocated memory.
  *
  * @see node_type::destroy
diff --git a/include/villas/node_type.h b/include/villas/node_type.h
index 82eaa743e..39b35ca3b 100644
--- a/include/villas/node_type.h
+++ b/include/villas/node_type.h
@@ -128,6 +128,14 @@ struct node_type {
 	 */
 	int (*start)(struct node *n);
 
+	/** Restart this node.
+	 *
+	 * @param n	A pointer to the node object.
+	 * @retval 0	Success. Everything went well.
+	 * @retval <0	Error. Something went wrong.
+	 */
+	int (*restart)(struct node *n);
+
 	/** Stop this node.
 	 *
 	 * @param n	A pointer to the node object.
@@ -136,6 +144,22 @@ struct node_type {
 	 */
 	int (*stop)(struct node *n);
 
+	/** Pause this node.
+	 *
+	 * @param n	A pointer to the node object.
+	 * @retval 0	Success. Everything went well.
+	 * @retval <0	Error. Something went wrong.
+	 */
+	int (*pause)(struct node *n);
+
+	/** Resume this node.
+	 *
+	 * @param n	A pointer to the node object.
+	 * @retval 0	Success. Everything went well.
+	 * @retval <0	Error. Something went wrong.
+	 */
+	int (*resume)(struct node *n);
+
 	/** Receive multiple messages at once.
 	 *
 	 * Messages are received with a single recvmsg() syscall by
diff --git a/lib/node.c b/lib/node.c
index fbbc8f653..6a219211a 100644
--- a/lib/node.c
+++ b/lib/node.c
@@ -380,6 +380,66 @@ int node_stop(struct node *n)
 	return ret;
 }
 
+int node_pause(struct node *n)
+{
+	int ret;
+
+	if (n->state != STATE_STARTED)
+		return -1;
+
+	info("Pausing node %s", node_name(n));
+
+	ret = node_type(n)->pause ? node_type(n)->pause(n) : 0;
+
+	if (ret == 0)
+		n->state = STATE_PAUSED;
+
+	return ret;
+}
+
+int node_resume(struct node *n)
+{
+	int ret;
+
+	if (n->state != STATE_PAUSED)
+		return -1;
+
+	info("Resuming node %s", node_name(n));
+
+	ret = node_type(n)->resume ? node_type(n)->resume(n) : 0;
+
+	if (ret == 0)
+		n->state = STATE_STARTED;
+
+	return ret;
+}
+
+int node_restart(struct node *n)
+{
+	int ret;
+
+	if (n->state != STATE_STARTED)
+		return -1;
+
+	info("Restarting node %s", node_name(n));
+
+	if (node_type(n)->restart) {
+		ret = node_type(n)->restart(n);
+	}
+	else {
+		ret = node_type(n)->stop ? node_type(n)->stop(n) : 0;
+		if (ret)
+			return ret;
+
+		ret = node_type(n)->start ? node_type(n)->start(n) : 0;
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+
 int node_destroy(struct node *n)
 {
 	int ret;