/*

 * QEMU aio implementation

 *

 * Copyright IBM, Corp. 2008

 *

 * Authors:

 *  Anthony Liguori   <aliguori@us.ibm.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 *

 */

#ifndef QEMU_AIO_H

#define QEMU_AIO_H

#include "qemu-common.h"

#include "qemu-char.h"

/* Returns 1 if there are still outstanding AIO requests; 0 otherwise */

typedef int (AioFlushHandler)(void *opaque);

/* Flush any pending AIO operation. This function will block until all

 * outstanding AIO operations have been completed or cancelled. */

void qemu_aio_flush(void);

/* Wait for a single AIO completion to occur.  This function will until a

 * single AIO opeartion has completed.  It is intended to be used as a looping

 * primative when simulating synchronous IO based on asynchronous IO. */

void qemu_aio_wait(void);

/* Register a file descriptor and associated callbacks.  Behaves very similarly

 * to qemu_set_fd_handler2.  Unlike qemu_set_fd_handler2, these callbacks will

 * be invoked when using either qemu_aio_wait() or qemu_aio_flush().

 *

 * Code that invokes AIO completion functions should rely on this function

 * instead of qemu_set_fd_handler[2].

 */

int qemu_aio_set_fd_handler(int fd,

                            IOHandler *io_read,

                            IOHandler *io_write,

                            AioFlushHandler *io_flush,

                            void *opaque);

#endif