libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait.pass.cpp

   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 // UNSUPPORTED: no-threads
  10
  11 // <condition_variable>
  12
  13 // class condition_variable;
  14
  15 // void wait(unique_lock<mutex>& lock);
  16
  17 #include <condition_variable>
  18 #include <mutex>
  19 #include <thread>
  20 #include <cassert>
  21
  22 #include "make_test_thread.h"
  23 #include "test_macros.h"
  24
  25 std::condition_variable cv;
  26 std::mutex mut;
  27
  28 int test1 = 0;
  29 int test2 = 0;
  30
  31 void f()
  32 {
  33     std::unique_lock<std::mutex> lk(mut);
  34     assert(test2 == 0);
  35     test1 = 1;
  36     cv.notify_one();
  37     while (test2 == 0)
  38         cv.wait(lk);
  39     assert(test2 != 0);
  40 }
  41
  42 int main(int, char**)
  43 {
  44     std::unique_lock<std::mutex> lk(mut);
  45     std::thread t = support::make_test_thread(f);
  46     assert(test1 == 0);
  47     while (test1 == 0)
  48         cv.wait(lk);
  49     assert(test1 != 0);
  50     test2 = 1;
  51     lk.unlock();
  52     cv.notify_one();
  53     t.join();
  54
  55   return 0;
  56 }