[Qemu-devel] [PATCH 04/12] aio: provide platform-independent API

[Paolo Bonzini <pbonzini@redhat.com>]

This adds to aio.c a platform-independent API based on EventNotifiers, that
can be used by the portable thread pool.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 aio.c      |    9 +++++++++
 qemu-aio.h |   19 ++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/aio.c b/aio.c
index 0a9eb10..417ceb4 100644
--- a/aio.c
+++ b/aio.c
@@ -97,6 +97,15 @@ int qemu_aio_set_fd_handler(int fd,
     return 0;
 }
 
+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 bfdd35f..89c766c 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 @@ int 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
-- 
1.7.10.4