libcxx/test/std/thread/thread.condition/thread.condition.condvarany/helpers.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef TEST_STD_THREAD_CONDITION_CONDVARANY_HELPERS_H
  10 #define TEST_STD_THREAD_CONDITION_CONDVARANY_HELPERS_H
  11
  12 #include <chrono>
  13 #include <cassert>
  14
  15 #include "test_macros.h"
  16
  17 #if TEST_STD_VER >= 17
  18
  19 // wait_for and wait_until function can exit via
  20 // - predicate is true
  21 // - timeout
  22 // - stop_requested
  23 // The return value only tells if the predicate is true
  24 // when the function exits, but it does not tell whether
  25 // it is timeout or stop_requested.
  26 //
  27 // ElapsedTimeCheck would fail the test if a test takes
  28 // longer than a duration. This is useful because we can
  29 // ensure that the wait_{for, until} function does not
  30 // wait until the timeout
  31 struct ElapsedTimeCheck {
  32   ElapsedTimeCheck(std::chrono::steady_clock::duration timeoutDuration)
  33       : timeout_(std::chrono::steady_clock::now() + timeoutDuration) {}
  34
  35   ElapsedTimeCheck(ElapsedTimeCheck&&)            = delete;
  36   ElapsedTimeCheck& operator=(ElapsedTimeCheck&&) = delete;
  37
  38   ~ElapsedTimeCheck() { assert(std::chrono::steady_clock::now() < timeout_); }
  39
  40   std::chrono::time_point<std::chrono::steady_clock> timeout_;
  41 };
  42
  43 #endif
  44
  45 #endif // TEST_STD_THREAD_CONDITION_CONDVARANY_HELPERS_H