LXR qemu/qemu-aio.h

   1/*
   2 * QEMU aio implementation
   3 *
   4 * Copyright IBM, Corp. 2008
   5 *
   6 * Authors:
   7 *  Anthony Liguori   <aliguori@us.ibm.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2.  See
  10 * the COPYING file in the top-level directory.
  11 *
  12 */
  13
  14#ifndef QEMU_AIO_H
  15#define QEMU_AIO_H
  16
  17#include "qemu-common.h"
  18#include "qemu-char.h"
  19
  20/* Returns 1 if there are still outstanding AIO requests; 0 otherwise */
  21typedef int (AioFlushHandler)(void *opaque);
  22
  23/* Flush any pending AIO operation. This function will block until all
  24 * outstanding AIO operations have been completed or cancelled. */
  25void qemu_aio_flush(void);
  26
  27/* Wait for a single AIO completion to occur.  This function will wait
  28 * until a single AIO event has completed and it will ensure something
  29 * has moved before returning. This can issue new pending aio as
  30 * result of executing I/O completion or bh callbacks. */
  31void qemu_aio_wait(void);
  32
  33/* Register a file descriptor and associated callbacks.  Behaves very similarly
  34 * to qemu_set_fd_handler2.  Unlike qemu_set_fd_handler2, these callbacks will
  35 * be invoked when using either qemu_aio_wait() or qemu_aio_flush().
  36 *
  37 * Code that invokes AIO completion functions should rely on this function
  38 * instead of qemu_set_fd_handler[2].
  39 */
  40int qemu_aio_set_fd_handler(int fd,
  41                            IOHandler *io_read,
  42                            IOHandler *io_write,
  43                            AioFlushHandler *io_flush,
  44                            void *opaque);
  45
  46#endif
  47