aio: add flag to skip fds to aio_dispatch()
Polling mode will not call ppoll(2)/epoll_wait(2). Therefore we know
there are no fds ready and should avoid looping over fd handlers in
aio_dispatch().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/aio-posix.c b/aio-posix.c
index e13b9ab..4ac2346 100644
--- a/aio-posix.c
+++ b/aio-posix.c
@@ -290,9 +290,13 @@
return false;
}
-bool aio_dispatch(AioContext *ctx)
+/*
+ * Note that dispatch_fds == false has the side-effect of post-poning the
+ * freeing of deleted handlers.
+ */
+bool aio_dispatch(AioContext *ctx, bool dispatch_fds)
{
- AioHandler *node;
+ AioHandler *node = NULL;
bool progress = false;
/*
@@ -308,7 +312,9 @@
* We have to walk very carefully in case aio_set_fd_handler is
* called while we're walking.
*/
- node = QLIST_FIRST(&ctx->aio_handlers);
+ if (dispatch_fds) {
+ node = QLIST_FIRST(&ctx->aio_handlers);
+ }
while (node) {
AioHandler *tmp;
int revents;
@@ -473,7 +479,7 @@
ctx->walking_handlers--;
/* Run dispatch even if there were no readable fds to run timers */
- if (aio_dispatch(ctx)) {
+ if (aio_dispatch(ctx, ret > 0)) {
progress = true;
}