From 429c07f1e36894802e0e3bbe6f161901e06f7fca Mon Sep 17 00:00:00 2001
From: Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
Date: Mon, 6 Mar 2017 13:26:23 -0400
Subject: [PATCH] add little FSM to pool, web, api, queue to track state of
 initialisation

---
 include/villas/api.h   |  5 +++++
 include/villas/pool.h  |  5 +++++
 include/villas/queue.h |  5 +++++
 include/villas/web.h   |  5 +++++
 lib/api.c              |  6 ++++++
 lib/pool.c             |  7 ++++++-
 lib/queue.c            | 11 ++++++++++-
 lib/web.c              |  7 ++++++-
 8 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/include/villas/api.h b/include/villas/api.h
index f6fb7a500..2258d7b90 100644
--- a/include/villas/api.h
+++ b/include/villas/api.h
@@ -43,6 +43,11 @@ enum api_mode {
 struct api {
 	struct list sessions;	/**< List of currently active connections */
 	
+	enum {
+		API_STATE_DESTROYED,
+		API_STATE_INITIALIZED
+	} state;
+	
 	struct cfg *cfg;
 };
 
diff --git a/include/villas/pool.h b/include/villas/pool.h
index f54f43081..5285b2a6e 100644
--- a/include/villas/pool.h
+++ b/include/villas/pool.h
@@ -19,6 +19,11 @@ struct pool {
 	void *buffer;		/**< Address of the underlying memory area */
 	const struct memtype *mem;
 	
+	enum {
+		POOL_STATE_DESTROYED,
+		POOL_STATE_INITIALIZED
+	} state;
+	
 	size_t len;		/**< Length of the underlying memory area */
 	
 	size_t blocksz;		/**< Length of a block in bytes */
diff --git a/include/villas/queue.h b/include/villas/queue.h
index 7c57a23fc..3137e874b 100644
--- a/include/villas/queue.h
+++ b/include/villas/queue.h
@@ -43,6 +43,11 @@ typedef char cacheline_pad_t[CACHELINE_SIZE];
 
 struct queue {
 	cacheline_pad_t _pad0;	/**< Shared area: all threads read */
+	
+	enum {
+		QUEUE_STATE_DESTROYED,
+		QUEUE_STATE_INITIALIZED
+	} state;
 
 	struct memtype const * mem;
 	size_t buffer_mask;
diff --git a/include/villas/web.h b/include/villas/web.h
index f9c720393..42c3f62dd 100644
--- a/include/villas/web.h
+++ b/include/villas/web.h
@@ -13,6 +13,11 @@ struct api;
 struct web {
 	struct api *api;
 	
+	enum {
+		WEB_STATE_DESTROYED,
+		WEB_STATE_INITIALIZED
+	} state;
+	
 	struct lws_context *context;	/**< The libwebsockets server context. */
 	struct lws_vhost *vhost;	/**< The libwebsockets vhost. */
 
diff --git a/lib/api.c b/lib/api.c
index f6a260593..5d8996053 100644
--- a/lib/api.c
+++ b/lib/api.c
@@ -224,12 +224,18 @@ int api_init(struct api *a, struct cfg *cfg)
 	list_init(&a->sessions);
 
 	a->cfg = cfg;
+	a->state = API_STATE_INITIALIZED;
 
 	return 0;
 }
 
 int api_destroy(struct api *a)
 {
+	// if (a->state = API_STATE_INITIALIZED)
+	//	do something
+
+	a->state = API_STATE_DESTROYED;
+
 	return 0;
 }
 
diff --git a/lib/pool.c b/lib/pool.c
index bd0eace0a..e80b5bff5 100644
--- a/lib/pool.c
+++ b/lib/pool.c
@@ -32,6 +32,8 @@ int pool_init(struct pool *p, size_t cnt, size_t blocksz, const struct memtype *
 	
 	for (int i = 0; i < cnt; i++)
 		queue_push(&p->queue, (char *) p->buffer + i * p->blocksz);
+	
+	p->state = POOL_STATE_INITIALIZED;
 
 	return 0;
 }
@@ -40,7 +42,10 @@ int pool_destroy(struct pool *p)
 {
 	queue_destroy(&p->queue);	
 
-	return memory_free(p->mem, p->buffer, p->len);
+	if (p->state == POOL_STATE_INITIALIZED)
+		return memory_free(p->mem, p->buffer, p->len);
 	
+	p->state = POOL_STATE_DESTROYED;
+
 	return 0;
 }
\ No newline at end of file
diff --git a/lib/queue.c b/lib/queue.c
index 7862dad4f..a2cc3bcc6 100644
--- a/lib/queue.c
+++ b/lib/queue.c
@@ -57,12 +57,21 @@ int queue_init(struct queue *q, size_t size, const struct memtype *mem)
 	atomic_store_explicit(&q->tail, 0, memory_order_relaxed);
 	atomic_store_explicit(&q->head, 0, memory_order_relaxed);
 	
+	q->state = QUEUE_STATE_INITIALIZED;
+	
 	return 0;
 }
 
 int queue_destroy(struct queue *q)
 {
-	return memory_free(q->mem, q->buffer, (q->buffer_mask + 1) * sizeof(q->buffer[0]));
+	int ret = 0;
+
+	if (q->state == QUEUE_STATE_INITIALIZED)
+		ret = memory_free(q->mem, q->buffer, (q->buffer_mask + 1) * sizeof(q->buffer[0]));
+
+	q->state = QUEUE_STATE_DESTROYED;
+	
+	return ret;
 }
 
 /** Return estimation of current queue usage.
diff --git a/lib/web.c b/lib/web.c
index ccd81baa6..6c8c218fd 100644
--- a/lib/web.c
+++ b/lib/web.c
@@ -162,13 +162,18 @@ int web_init(struct web *w, struct api *a)
 	w->vhost = lws_create_vhost(w->context, &vhost_info);
 	if (w->vhost == NULL)
 		error("WebSocket: failed to initialize server");
+	
+	w->state = WEB_STATE_INITIALIZED;
 
 	return 0;
 }
 
 int web_destroy(struct web *w)
 {
-	lws_context_destroy(w->context);
+	if (w->state == WEB_STATE_INITIALIZED)
+		lws_context_destroy(w->context);
+
+	w->state = WEB_STATE_DESTROYED;
 
 	return 0;
 }