Re: [Qemu-devel] [PATCH v6 04/18] tests: adjust test-aio to new aio_poll() semantics

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> aio_poll(ctx, true) will soon block if any fd handlers have been set.
> Previously it would only block when .io_flush() returned true.
> 
> This means that callers must check their wait condition *before*
> aio_poll() to avoid deadlock.
> 
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   tests/test-aio.c | 26 +++++++++++++++++---------
>   1 file changed, 17 insertions(+), 9 deletions(-)
> 
> diff --git a/tests/test-aio.c b/tests/test-aio.c
> index c173870..20bf5e6 100644
> --- a/tests/test-aio.c
> +++ b/tests/test-aio.c
> @@ -15,6 +15,13 @@
> 
>   AioContext *ctx;
> 
> +typedef struct {
> +    EventNotifier e;
> +    int n;
> +    int active;
> +    bool auto_set;
> +} EventNotifierTestData;
> +
>   /* Wait until there are no more BHs or AIO requests */
>   static void wait_for_aio(void)
>   {
> @@ -23,6 +30,14 @@ static void wait_for_aio(void)
>       }
>   }
> 
> +/* Wait until event notifier becomes inactive */
> +static void wait_until_inactive(EventNotifierTestData *data)
> +{
> +    while (data->active > 0) {
> +        aio_poll(ctx, true);
> +    }
> +}
> +
>   /* Simple callbacks for testing.  */
> 
>   typedef struct {
> @@ -50,13 +65,6 @@ static void bh_delete_cb(void *opaque)
>       }
>   }
> 
> -typedef struct {
> -    EventNotifier e;
> -    int n;
> -    int active;
> -    bool auto_set;
> -} EventNotifierTestData;
> -
>   static int event_active_cb(EventNotifier *e)
>   {
>       EventNotifierTestData *data = container_of(e, EventNotifierTestData, e);
> @@ -281,7 +289,7 @@ static void test_flush_event_notifier(void)
>       g_assert_cmpint(data.active, ==, 9);
>       g_assert(aio_poll(ctx, false));
> 
> -    wait_for_aio();
> +    wait_until_inactive(&data);
>       g_assert_cmpint(data.n, ==, 10);
>       g_assert_cmpint(data.active, ==, 0);
>       g_assert(!aio_poll(ctx, false));
> @@ -325,7 +333,7 @@ static void test_wait_event_notifier_noflush(void)
>       g_assert_cmpint(data.n, ==, 2);
> 
>       event_notifier_set(&dummy.e);
> -    wait_for_aio();
> +    wait_until_inactive(&dummy);
>       g_assert_cmpint(data.n, ==, 2);
>       g_assert_cmpint(dummy.n, ==, 1);
>       g_assert_cmpint(dummy.active, ==, 0);
> 


-- 
Best Regards

Wenchao Xia