Spdk/include/spdk_internal/init.h

/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.  All rights reserved.
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 *   modification, are permitted provided that the following conditions
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 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
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 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 * SPDK Initialization Helper
 */

#ifndef SPDK_INIT_H
#define SPDK_INIT_H

#include "spdk/stdinc.h"
#include "spdk/queue.h"

#ifdef __cplusplus
extern "C" {
#endif

struct spdk_json_write_ctx;

struct spdk_subsystem {
	const char *name;
	/* User must call spdk_subsystem_init_next() when they are done with their initialization. */
	void (*init)(void);
	void (*fini)(void);

	/**
	 * Write JSON configuration handler.
	 *
	 * \param w JSON write context
	 */
	void (*write_config_json)(struct spdk_json_write_ctx *w);
	TAILQ_ENTRY(spdk_subsystem) tailq;
};

struct spdk_subsystem *spdk_subsystem_find(const char *name);
struct spdk_subsystem *spdk_subsystem_get_first(void);
struct spdk_subsystem *spdk_subsystem_get_next(struct spdk_subsystem *cur_subsystem);

struct spdk_subsystem_depend {
	const char *name;
	const char *depends_on;
	TAILQ_ENTRY(spdk_subsystem_depend) tailq;
};

struct spdk_subsystem_depend *spdk_subsystem_get_first_depend(void);
struct spdk_subsystem_depend *spdk_subsystem_get_next_depend(struct spdk_subsystem_depend
		*cur_depend);

void spdk_add_subsystem(struct spdk_subsystem *subsystem);
void spdk_add_subsystem_depend(struct spdk_subsystem_depend *depend);

typedef void (*spdk_subsystem_init_fn)(int rc, void *ctx);
void spdk_subsystem_init(spdk_subsystem_init_fn cb_fn, void *cb_arg);

typedef void (*spdk_subsystem_fini_fn)(void *ctx);
void spdk_subsystem_fini(spdk_subsystem_fini_fn cb_fn, void *cb_arg);
void spdk_subsystem_init_next(int rc);
void spdk_subsystem_fini_next(void);

/**
 * Save pointed \c subsystem configuration to the JSON write context \c w. In case of
 * error \c null is written to the JSON context.
 *
 * \param w JSON write context
 * \param subsystem the subsystem to query
 */
void spdk_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_subsystem *subsystem);

/**
 * \brief Register a new subsystem
 */
#define SPDK_SUBSYSTEM_REGISTER(_name) \
	__attribute__((constructor)) static void _name ## _register(void)	\
	{									\
		spdk_add_subsystem(&_name);					\
	}

/**
 * \brief Declare that a subsystem depends on another subsystem.
 */
#define SPDK_SUBSYSTEM_DEPEND(_name, _depends_on)						\
	static struct spdk_subsystem_depend __subsystem_ ## _name ## _depend_on ## _depends_on = { \
	.name = #_name,										\
	.depends_on = #_depends_on,								\
	};											\
	__attribute__((constructor)) static void _name ## _depend_on ## _depends_on(void)	\
	{											\
		spdk_add_subsystem_depend(&__subsystem_ ## _name ## _depend_on ## _depends_on); \
	}

#ifdef __cplusplus
}
#endif

#endif