Merge pull request #165 from robertbaldyga/ctx-get-put

Give ocf_ctx get/put semantics

doc/HOME.md

@@ -90,7 +90,7 @@ int my_cache_init(void)
 {
 	int result;
 
-	result ocf_ctx_init(&ctx, &ctx_ops)
+	result = ocf_ctx_create(&ctx, &ctx_ops)
 	if (result) {
 		/* Cannot initialze context of OCF library */
 		return result;
@@ -116,7 +116,7 @@ int my_cache_init(void)
 
 err:
 	/* In case of failure we destroy context and propagate error code */
-	ocf_ctx_exit(ctx);
+	ocf_ctx_put(ctx);
 	return result;
 }
 

example/simple/src/ctx.c

@@ -278,13 +278,13 @@ int ctx_init(ocf_ctx_t *ctx)
 {
 	int ret;
 
-	ret = ocf_ctx_init(ctx, &ctx_cfg);
+	ret = ocf_ctx_create(ctx, &ctx_cfg);
 	if (ret)
 		return ret;
 
 	ret = volume_init(*ctx);
 	if (ret) {
-		ocf_ctx_exit(*ctx);
+		ocf_ctx_put(*ctx);
 		return ret;
 	}
 
@@ -298,5 +298,5 @@ int ctx_init(ocf_ctx_t *ctx)
 void ctx_cleanup(ocf_ctx_t ctx)
 {
 	volume_cleanup(ctx);
-	ocf_ctx_exit(ctx);
+	ocf_ctx_put(ctx);
 }

inc/ocf_ctx.h

@@ -285,24 +285,27 @@ int ocf_ctx_volume_create(ocf_ctx_t ctx, ocf_volume_t *volume,
 		struct ocf_volume_uuid *uuid, uint8_t type_id);
 
 /**
- * @brief Initialize OCF context
+ * @brief Create and initialize OCF context
  *
  * @param[out] ctx OCF context
  * @param[in] ops OCF context operations
  *
  * @return Zero when success, otherwise an error
  */
-int ocf_ctx_init(ocf_ctx_t *ctx, const struct ocf_ctx_config *cfg);
+int ocf_ctx_create(ocf_ctx_t *ctx, const struct ocf_ctx_config *cfg);
 
 /**
- * @brief De-Initialize OCF context
+ * @brief Increase reference counter of ctx
  *
  * @param[in] ctx OCF context
- *
- * @note Precondition is stopping all cache instances
- *
- * @return Zero when success, otherwise an error
  */
-int ocf_ctx_exit(ocf_ctx_t ctx);
+void ocf_ctx_get(ocf_ctx_t ctx);
+
+/**
+ * @brief Decrease reference counter of ctx
+ *
+ * @param[in] ctx OCF context
+ */
+void ocf_ctx_put(ocf_ctx_t ctx);
 
 #endif /* __OCF_CTX_H__ */

src/mngt/ocf_mngt_cache.c

@@ -1216,6 +1216,8 @@ static int _ocf_mngt_cache_start(ocf_ctx_t ctx, ocf_cache_t *cache,
 	if (result)
 		goto _cache_mng_init_instance_ERROR;
 
+	ocf_ctx_get(ctx);
+
 	if (params.locked) {
 		/* Increment reference counter to match cache_lock /
 		   cache_unlock convention. User is expected to call

src/mngt/ocf_mngt_common.c

@@ -119,11 +119,15 @@ void cache_mng_core_remove_from_cache(struct ocf_cache *cache, int core_id)
 
 void ocf_mngt_cache_put(ocf_cache_t cache)
 {
+	ocf_ctx_t ctx;
+
 	OCF_CHECK_NULL(cache);
 
 	if (ocf_refcnt_dec(&cache->refcnt.cache) == 0) {
+		ctx = cache->owner;
 		ocf_metadata_deinit(cache);
 		env_vfree(cache);
+		ocf_ctx_put(ctx);
 	}
 }
 

src/ocf_ctx.c

@@ -114,7 +114,7 @@ int ocf_ctx_volume_create(ocf_ctx_t ctx, ocf_volume_t *volume,
 /*
  *
  */
-int ocf_ctx_init(ocf_ctx_t *ctx, const struct ocf_ctx_config *cfg)
+int ocf_ctx_create(ocf_ctx_t *ctx, const struct ocf_ctx_config *cfg)
 {
 	ocf_ctx_t ocf_ctx;
 	int ret;
@@ -127,6 +127,7 @@ int ocf_ctx_init(ocf_ctx_t *ctx, const struct ocf_ctx_config *cfg)
 		return -ENOMEM;
 
 	INIT_LIST_HEAD(&ocf_ctx->caches);
+	env_atomic_set(&ocf_ctx->ref_count, 1);
 	ret = env_mutex_init(&ocf_ctx->lock);
 	if (ret)
 		goto err_ctx;
@@ -166,25 +167,30 @@ err_ctx:
 /*
  *
  */
-int ocf_ctx_exit(ocf_ctx_t ctx)
+void ocf_ctx_get(ocf_ctx_t ctx)
 {
-	int result = 0;
-
 	OCF_CHECK_NULL(ctx);
 
-	/* Check if caches are setup */
+	env_atomic_inc(&ctx->ref_count);
+}
+
+/*
+ *
+ */
+void ocf_ctx_put(ocf_ctx_t ctx)
+{
+	OCF_CHECK_NULL(ctx);
+
+	if (env_atomic_dec_return(&ctx->ref_count))
+		return;
+
 	env_mutex_lock(&ctx->lock);
-	if (!list_empty(&ctx->caches))
-		result = -EEXIST;
+	ENV_BUG_ON(!list_empty(&ctx->caches));
 	env_mutex_unlock(&ctx->lock);
-	if (result)
-		return result;
 
 	ocf_mngt_core_pool_deinit(ctx);
 	ocf_core_volume_type_deinit(ctx);
 	ocf_utils_deinit(ctx);
 	ocf_logger_close(&ctx->logger);
 	env_free(ctx);
-
-	return 0;
 }

src/ocf_ctx_priv.h

@@ -20,6 +20,7 @@ struct ocf_ctx {
 	const struct ocf_ctx_config *cfg;
 	struct ocf_logger logger;
 	struct ocf_volume_type *volume_type[OCF_VOLUME_TYPE_MAX];
+	env_atomic ref_count;
 	env_mutex lock;
 	struct list_head caches;
 	struct {

tests/functional/pyocf/types/ctx.py

@@ -51,7 +51,7 @@ class OcfCtx:
             logger_priv=cast(pointer(logger.get_priv()), c_void_p),
         )
 
-        result = self.lib.ocf_ctx_init(byref(self.ctx_handle), byref(self.cfg))
+        result = self.lib.ocf_ctx_create(byref(self.ctx_handle), byref(self.cfg))
         if result != 0:
             raise OcfError("Context initialization failed", result)
 
@@ -95,9 +95,7 @@ class OcfCtx:
         self.stop_caches()
         self.cleanup_volume_types()
 
-        result = self.lib.ocf_ctx_exit(self.ctx_handle)
-        if result != 0:
-            raise OcfError("Failed quitting OcfCtx", result)
+        self.lib.ocf_ctx_put(self.ctx_handle)
 
         self.cfg = None
         self.logger = None