libcxx/test/std/thread/futures/futures.unique_future/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: libcpp-has-no-threads
  10 // UNSUPPORTED: c++03
  11
  12 // <future>
  13
  14 // class future<R>
  15
  16 // void wait() const;
  17
  18 #include <future>
  19 #include <cassert>
  20
  21 #include "make_test_thread.h"
  22 #include "test_macros.h"
  23
  24 void func1(std::promise<int> p)
  25 {
  26     std::this_thread::sleep_for(std::chrono::milliseconds(500));
  27     p.set_value(3);
  28 }
  29
  30 int j = 0;
  31
  32 void func3(std::promise<int&> p)
  33 {
  34     std::this_thread::sleep_for(std::chrono::milliseconds(500));
  35     j = 5;
  36     p.set_value(j);
  37 }
  38
  39 void func5(std::promise<void> p)
  40 {
  41     std::this_thread::sleep_for(std::chrono::milliseconds(500));
  42     p.set_value();
  43 }
  44
  45 template <typename T, typename F>
  46 void test(F func) {
  47     typedef std::chrono::high_resolution_clock Clock;
  48     typedef std::chrono::duration<double, std::milli> ms;
  49
  50     std::promise<T> p;
  51     std::future<T> f = p.get_future();
  52     support::make_test_thread(func, std::move(p)).detach();
  53     assert(f.valid());
  54     f.wait();
  55     assert(f.valid());
  56     Clock::time_point t0 = Clock::now();
  57     f.wait();
  58     Clock::time_point t1 = Clock::now();
  59     assert(f.valid());
  60     assert(t1-t0 < ms(5));
  61 }
  62
  63 int main(int, char**)
  64 {
  65     test<int>(func1);
  66     test<int&>(func3);
  67     test<void>(func5);
  68     return 0;
  69 }