/* * 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); /* Runs all currently allowed AIO callbacks of completed requests in the * respective AIO backend. Returns 0 if no requests was handled, non-zero * if at least one queued request was handled. */ typedef int (AioProcessQueue)(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. */ void qemu_aio_wait(void); /* * Runs all currently allowed AIO callbacks of completed requests. Returns 0 * if no requests were handled, non-zero if at least one request was * processed. */ int qemu_aio_process_queue(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, AioProcessQueue *io_process_queue, void *opaque); #endif