The repeated calls to WaitForMultipleObjects may cause a livelock in aio_poll, where no progress is made on bottom halves. This patch matches the behavior of the POSIX code.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- Found by the new unit tests. aio-win32.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/aio-win32.c b/aio-win32.c index a84eb71..cec4646 100644 --- a/aio-win32.c +++ b/aio-win32.c @@ -173,7 +173,7 @@ bool aio_poll(AioContext *ctx, bool blocking) } /* wait until next event */ - for (;;) { + while (count > 0) { int timeout = blocking ? INFINITE : 0; int ret = WaitForMultipleObjects(count, events, FALSE, timeout); @@ -209,6 +209,9 @@ bool aio_poll(AioContext *ctx, bool blocking) g_free(tmp); } } + + /* Try again, but only call each handler once. */ + events[ret - WAIT_OBJECT_0] = events[--count]; } return progress; -- 1.8.0