/**
 * =========================================================================
 * File        : waio.h
 * Project     : 0 A.D.
 * Description : emulate POSIX asynchronous I/O on Windows.
 *
 * @author Jan.Wassenberg@stud.uni-karlsruhe.de
 * =========================================================================
 */

/*
 * Copyright (c) 2003-2004 Jan Wassenberg
 *
 * Redistribution and/or modification are also permitted under the
 * terms of the GNU General Public License as published by the
 * Free Software Foundation (version 2 or later, at your option).
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef WAIO_H__
#define WAIO_H__

#include "lib/types.h"
#include "wposix_types.h"


// Note: for maximum efficiency, transfer buffers, offsets, and lengths
// should be sector aligned (otherwise, buffer is copied).


//
// <signal.h>
//

union sigval
{
	int sival_int;				// Integer signal value.
	void* sival_ptr;			// Pointer signal value.
};

struct sigevent
{
	int sigev_notify;			// notification mode
	int sigev_signo;			// signal number
	union sigval sigev_value;	// signal value
	void (*sigev_notify_function)(union sigval);
};


//
// <aio.h>
//

struct aiocb
{
	int             aio_fildes;     // File descriptor.
	off_t           aio_offset;     // File offset.
	volatile void*  aio_buf;        // Location of buffer.
	size_t          aio_nbytes;     // Length of transfer.
	int             aio_reqprio;    // Request priority offset.
	struct sigevent aio_sigevent;   // Signal number and value.
	int             aio_lio_opcode; // Operation to be performed.
};

enum
{
	// aio_cancel return
	AIO_ALLDONE,     // None of the requested operations could be canceled since they are already complete. 
	AIO_CANCELED,    // All requested operations have been canceled. 
	AIO_NOTCANCELED, // Some of the requested operations could not be canceled since they are in progress. 

	// lio_listio mode
	LIO_WAIT,        // wait until all I/O is complete
	LIO_NOWAIT,

	// lio_listio ops
	LIO_NOP,
	LIO_READ,
	LIO_WRITE
};

extern int aio_cancel(int, struct aiocb*);
extern int aio_error(const struct aiocb*);
extern int aio_fsync(int, struct aiocb*);
extern int aio_read(struct aiocb*);
extern ssize_t aio_return(struct aiocb*);
extern int aio_suspend(const struct aiocb* const[], int, const struct timespec*);
extern int aio_write(struct aiocb*);
extern int lio_listio(int, struct aiocb* const[], int, struct sigevent*);

extern int aio_close(int fd);
extern int aio_reopen(int fd, const char* fn, int oflag, ...);

// allocate and return a file descriptor 
extern int aio_assign_handle(uintptr_t handle);

#endif	// #ifndef WAIO_H__