// SPDX-License-Identifier: GPL-2.0

//

// waiter.h - a header for I/O event waiter.

//

// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>

//

// Licensed under the terms of the GNU General Public License, version 2.

#ifndef __ALSA_UTILS_AXFER_WAITER__H_

#define __ALSA_UTILS_AXFER_WAITER__H_

#include <poll.h>

enum waiter_type {

	WAITER_TYPE_DEFAULT = 0,

	WAITER_TYPE_POLL,

	WAITER_TYPE_SELECT,

	WAITER_TYPE_EPOLL,

	WAITER_TYPE_COUNT,

};

struct waiter_ops;

struct waiter_context {

	enum waiter_type type;

	const struct waiter_ops *ops;

	void *private_data;

	struct pollfd *pfds;

	unsigned int pfd_count;

};

enum waiter_type waiter_type_from_label(const char *label);

const char *waiter_label_from_type(enum waiter_type type);

int waiter_context_init(struct waiter_context *waiter,

			enum waiter_type type, unsigned int pfd_count);

int waiter_context_prepare(struct waiter_context *waiter);

int waiter_context_wait_event(struct waiter_context *waiter,

				int timeout_msec);

void waiter_context_release(struct waiter_context *waiter);

void waiter_context_destroy(struct waiter_context *waiter);

// For internal use in 'waiter' module.

struct waiter_ops {

	int (*prepare)(struct waiter_context *waiter);

	int (*wait_event)(struct waiter_context *waiter, int timeout_msec);

	void (*release)(struct waiter_context *waiter);

};

struct waiter_data {

	struct waiter_ops ops;

	unsigned int private_size;

};

extern const struct waiter_data waiter_poll;

extern const struct waiter_data waiter_select;

extern const struct waiter_data waiter_epoll;

#endif