multi_threaded_tests.md

Multi-threaded tests

When writing multi-threaded test cases the following pitfalls needs to be avoided:

1. Uncaught assertions (thrown by cute or from your code) in separate threads are leading to call std::terminate(): it must be ensured that all exceptions are caught on the separate thread. cute::thread can be used for this purpose. It is just a simple wrapper around std::thread and wraps the execution with a catch-all-exceptions handler signalling an unhandled exception as a test failure.

2. std::threads need to be joined before their lifetime ends otherwise it leads to calling std::terminate(): cute::thread can be used for this purpose as well, since it ensures proper joining of the wrapped std::thread prior to it's destruction.

3. Test validation calls are thread safe: cute has been designed right from it's beginning with multi-threading in mind and all test validation calls can be safely used in arbitrary threads.

CUTE_TEST("A passed check in a separate thread is detected") {
    auto t = cute::thread([&]() { CUTE_ASSERT(true); });
}

// this test will fail (as expected)
CUTE_TEST("A failed check in a separate thread is detected") {
    auto t = cute::thread([&]() { CUTE_ASSERT(false); });
}

// this test will fail (as expected)
CUTE_TEST("An unhandled exception in a cute::thread is detected") {
    auto t = cute::thread([&]() { throw std::runtime_error("forced exception"); });
}

TODO

• describe usage of cute::tick