From 0a9dd1664a0509f7c3c0c7a5550446258ee70f4b Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 9 Jul 2014 11:53:07 +0200 Subject: [PATCH] aio-win32: add aio_set_dispatching optimization Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi --- aio-win32.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/aio-win32.c b/aio-win32.c index 1ec434a83c..fd526864be 100644 --- a/aio-win32.c +++ b/aio-win32.c @@ -144,12 +144,25 @@ bool aio_poll(AioContext *ctx, bool blocking) { AioHandler *node; HANDLE events[MAXIMUM_WAIT_OBJECTS + 1]; - bool progress, first; + bool was_dispatching, progress, first; int count; int timeout; + was_dispatching = ctx->dispatching; progress = false; + /* aio_notify can avoid the expensive event_notifier_set if + * everything (file descriptors, bottom halves, timers) will + * be re-evaluated before the next blocking poll(). This is + * already true when aio_poll is called with blocking == false; + * if blocking == true, it is only true after poll() returns. + * + * If we're in a nested event loop, ctx->dispatching might be true. + * In that case we can restore it just before returning, but we + * have to clear it now. + */ + aio_set_dispatching(ctx, !blocking); + ctx->walking_handlers++; /* fill fd sets */ @@ -170,6 +183,7 @@ bool aio_poll(AioContext *ctx, bool blocking) timeout = blocking ? qemu_timeout_ns_to_ms(aio_compute_timeout(ctx)) : 0; ret = WaitForMultipleObjects(count, events, FALSE, timeout); + aio_set_dispatching(ctx, true); if (first && aio_bh_poll(ctx)) { progress = true; @@ -191,5 +205,6 @@ bool aio_poll(AioContext *ctx, bool blocking) progress |= timerlistgroup_run_timers(&ctx->tlg); + aio_set_dispatching(ctx, was_dispatching); return progress; } -- 2.11.4.GIT