/* * 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" typedef struct BlockDriverAIOCB BlockDriverAIOCB; typedef void BlockDriverCompletionFunc(void *opaque, int ret); typedef struct AIOPool { void (*cancel)(BlockDriverAIOCB *acb); int aiocb_size; BlockDriverAIOCB *free_aiocb; } AIOPool; struct BlockDriverAIOCB { AIOPool *pool; BlockDriverState *bs; BlockDriverCompletionFunc *cb; void *opaque; BlockDriverAIOCB *next; }; void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque); void qemu_aio_release(void *p); /* 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 wait * until a single AIO event has completed and it will ensure something * has moved before returning. This can issue new pending aio as * result of executing I/O completion or bh callbacks. * * Return whether there is still any pending AIO operation. */ bool 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