From f639343dc8c4fa65342a8c1fd43384999cf9f9d0 Mon Sep 17 00:00:00 2001 From: Mike Crowe Date: Fri, 11 Sep 2020 14:24:59 +0100 Subject: [PATCH] libstdc++: Improve std::async test Add tests for waiting for the future using both chrono::steady_clock and chrono::system_clock in preparation for dealing with those clocks properly in futex.cc. libstdc++-v3/ChangeLog: * testsuite/30_threads/async/async.cc (test02): Test steady_clock with std::future::wait_until. (test03): Add new test templated on clock type waiting for future associated with async to resolve. (main): Call test03 to test both system_clock and steady_clock. --- .../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 8c3a0c18768..2089b1c45ef 100644 --- a/libstdc++-v3/testsuite/30_threads/async/async.cc +++ b/libstdc++-v3/testsuite/30_threads/async/async.cc @@ -50,17 +50,50 @@ 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 when CLOCK is std::chrono::system_clock. +template +void test03() +{ + auto const start = CLOCK::now(); + future f1 = async(launch::async, []() { + std::this_thread::sleep_for(std::chrono::seconds(2)); + }); + std::future_status status; + + status = f1.wait_for(std::chrono::milliseconds(500)); + VERIFY( status == std::future_status::timeout ); + + status = f1.wait_until(start + std::chrono::seconds(1)); + VERIFY( status == std::future_status::timeout ); + + status = f1.wait_until(start + std::chrono::seconds(5)); + VERIFY( status == std::future_status::ready ); + + auto const elapsed = CLOCK::now() - start; + VERIFY( elapsed >= std::chrono::seconds(2) ); + VERIFY( elapsed < std::chrono::seconds(5) ); } int main() { test01(); test02(); + test03(); + test03(); return 0; } -- 2.30.2