Re: [PATCHv3 1/6] Improve libstdc++-v3 async test

[Jonathan Wakely <jwakely at redhat dot com>]

On 01/08/18 14:19 +0100, Mike Crowe wrote:
> Add tests for waiting for the future using both std::chrono::steady_clock
> and std::chrono::system_clock in preparation for dealing with those clocks
> properly in futex.cc.
> ---
> libstdc++-v3/testsuite/30_threads/async/async.cc | 33 ++++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
>
> diff --git a/libstdc++-v3/testsuite/30_threads/async/async.cc b/libstdc++-v3/testsuite/30_threads/async/async.cc
> index 4c2cdd1a534..015bcce0c2c 100644
> --- a/libstdc++-v3/testsuite/30_threads/async/async.cc
> +++ b/libstdc++-v3/testsuite/30_threads/async/async.cc
> @@ -51,17 +51,50 @@ void test02()
>   VERIFY( status == std::future_status::timeout );
>   status = f1.wait_until(std::chrono::system_clock::now());
>   VERIFY( status == std::future_status::timeout );
> +  status = f1.wait_until(std::chrono::steady_clock::now());
> +  VERIFY( status == std::future_status::timeout );
>   l.unlock();  // allow async thread to proceed
>   f1.wait();   // wait for it to finish
>   status = f1.wait_for(std::chrono::milliseconds(0));
>   VERIFY( status == std::future_status::ready );
>   status = f1.wait_until(std::chrono::system_clock::now());
>   VERIFY( status == std::future_status::ready );
> +  status = f1.wait_until(std::chrono::steady_clock::now());
> +  VERIFY( status == std::future_status::ready );
> +}
> +
> +// This test is prone to failures if run on a loaded machine where the
> +// kernel decides not to schedule us for several seconds. It also
> +// assumes that no-one will warp CLOCK whilst the test is
> +// running.
> +template<typename CLOCK>
> +void test03()
> +{
> +  auto const start = CLOCK::now();
> +  future<void> f1 = async(launch::async, []() {
> +      std::this_thread::sleep_for(std::chrono::seconds(2));

Thanks for reducing these times since the last patch. I think this
test improvement can go on trunk, and if we see too many failures we
can adjust the times.