[05/17] aio: provide platform-independent API

This adds to aio.c a platform-independent API based on EventNotifiers, that
can be used by both POSIX and Win32.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Makefile.objs |  4 ++--
 aio.c         |  9 +++++++++
 qemu-aio.h    | 19 ++++++++++++++++++-
 3 file modificati, 29 inserzioni(+), 3 rimozioni(-)

Paolo Bonzini <pbonzini@redhat.com> writes:

> This adds to aio.c a platform-independent API based on EventNotifiers, that
> can be used by both POSIX and Win32.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>

Regards,

Anthony Liguori

> ---
>  Makefile.objs |  4 ++--
>  aio.c         |  9 +++++++++
>  qemu-aio.h    | 19 ++++++++++++++++++-
>  3 file modificati, 29 inserzioni(+), 3 rimozioni(-)
>
> diff --git a/Makefile.objs b/Makefile.objs
> index a99378c..713dd87 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -45,6 +45,8 @@ block-obj-y = iov.o cache-utils.o qemu-option.o module.o async.o
>  block-obj-y += nbd.o block.o aio.o aes.o qemu-config.o qemu-progress.o qemu-sockets.o
>  block-obj-y += $(coroutine-obj-y) $(qobject-obj-y) $(version-obj-y)
>  block-obj-$(CONFIG_POSIX) += posix-aio-compat.o
> +block-obj-$(CONFIG_POSIX) += event_notifier-posix.o
> +block-obj-$(CONFIG_WIN32) += event_notifier-win32.o
>  block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
>  block-obj-y += block/
>  
> @@ -92,8 +94,6 @@ common-obj-y += bt-host.o bt-vhci.o
>  common-obj-y += acl.o
>  common-obj-$(CONFIG_POSIX) += compatfd.o
>  common-obj-y += notify.o
> -common-obj-$(CONFIG_POSIX) += event_notifier-posix.o
> -common-obj-$(CONFIG_WIN32) += event_notifier-win32.o
>  common-obj-y += qemu-timer.o qemu-timer-common.o
>  
>  common-obj-$(CONFIG_SLIRP) += slirp/
> diff --git a/aio.c b/aio.c
> index e062aab..44214e1 100644
> --- a/aio.c
> +++ b/aio.c
> @@ -95,6 +95,15 @@ void qemu_aio_set_fd_handler(int fd,
>      qemu_set_fd_handler2(fd, NULL, io_read, io_write, opaque);
>  }
>  
> +void qemu_aio_set_event_notifier(EventNotifier *notifier,
> +                                 EventNotifierHandler *io_read,
> +                                 AioFlushEventNotifierHandler *io_flush)
> +{
> +    qemu_aio_set_fd_handler(event_notifier_get_fd(notifier),
> +                            (IOHandler *)io_read, NULL,
> +                            (AioFlushHandler *)io_flush, notifier);
> +}
> +
>  void qemu_aio_flush(void)
>  {
>      while (qemu_aio_wait());
> diff --git a/qemu-aio.h b/qemu-aio.h
> index 27a7e21..dc416a5 100644
> --- a/qemu-aio.h
> +++ b/qemu-aio.h
> @@ -16,6 +16,7 @@
>  
>  #include "qemu-common.h"
>  #include "qemu-char.h"
> +#include "event_notifier.h"
>  
>  typedef struct BlockDriverAIOCB BlockDriverAIOCB;
>  typedef void BlockDriverCompletionFunc(void *opaque, int ret);
> @@ -39,7 +40,7 @@ void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
>  void qemu_aio_release(void *p);
>  
>  /* Returns 1 if there are still outstanding AIO requests; 0 otherwise */
> -typedef int (AioFlushHandler)(void *opaque);
> +typedef int (AioFlushEventNotifierHandler)(EventNotifier *e);
>  
>  /* Flush any pending AIO operation. This function will block until all
>   * outstanding AIO operations have been completed or cancelled. */
> @@ -53,6 +54,10 @@ void qemu_aio_flush(void);
>   * Return whether there is still any pending AIO operation.  */
>  bool qemu_aio_wait(void);
>  
> +#ifdef CONFIG_POSIX
> +/* Returns 1 if there are still outstanding AIO requests; 0 otherwise */
> +typedef int (AioFlushHandler)(void *opaque);
> +
>  /* 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().
> @@ -65,5 +70,17 @@ void qemu_aio_set_fd_handler(int fd,
>                               IOHandler *io_write,
>                               AioFlushHandler *io_flush,
>                               void *opaque);
> +#endif
> +
> +/* Register an event notifier and associated callbacks.  Behaves very similarly
> + * to event_notifier_set_handler.  Unlike event_notifier_set_handler, 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 event_notifier_set_handler.
> + */
> +void qemu_aio_set_event_notifier(EventNotifier *notifier,
> +                                 EventNotifierHandler *io_read,
> +                                 AioFlushEventNotifierHandler *io_flush);
>  
>  #endif
> -- 
> 1.7.12