libcxx/test/std/thread/futures/futures.shared_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: no-threads
  10 // UNSUPPORTED: c++03
  11
  12 // <future>
  13
  14 // class shared_future<R>
  15
  16 // void wait() const;
  17
  18 #include <cassert>
  19 #include <chrono>
  20 #include <future>
  21 #include <ratio>
  22
  23 #include "make_test_thread.h"
  24 #include "test_macros.h"
  25
  26 void func1(std::promise<int> p)
  27 {
  28     std::this_thread::sleep_for(std::chrono::milliseconds(500));
  29     p.set_value(3);
  30 }
  31
  32 int j = 0;
  33
  34 void func3(std::promise<int&> p)
  35 {
  36     std::this_thread::sleep_for(std::chrono::milliseconds(500));
  37     j = 5;
  38     p.set_value(j);
  39 }
  40
  41 void func5(std::promise<void> p)
  42 {
  43     std::this_thread::sleep_for(std::chrono::milliseconds(500));
  44     p.set_value();
  45 }
  46
  47 int main(int, char**)
  48 {
  49     typedef std::chrono::high_resolution_clock Clock;
  50     typedef std::chrono::duration<double, std::milli> ms;
  51     {
  52         typedef int T;
  53         std::promise<T> p;
  54         std::shared_future<T> f = p.get_future();
  55         support::make_test_thread(func1, std::move(p)).detach();
  56         assert(f.valid());
  57         f.wait();
  58         assert(f.valid());
  59         Clock::time_point t0 = Clock::now();
  60         f.wait();
  61         Clock::time_point t1 = Clock::now();
  62         assert(f.valid());
  63         assert(t1-t0 < ms(5));
  64     }
  65     {
  66         typedef int& T;
  67         std::promise<T> p;
  68         std::shared_future<T> f = p.get_future();
  69         support::make_test_thread(func3, std::move(p)).detach();
  70         assert(f.valid());
  71         f.wait();
  72         assert(f.valid());
  73         Clock::time_point t0 = Clock::now();
  74         f.wait();
  75         Clock::time_point t1 = Clock::now();
  76         assert(f.valid());
  77         assert(t1-t0 < ms(5));
  78     }
  79     {
  80         typedef void T;
  81         std::promise<T> p;
  82         std::shared_future<T> f = p.get_future();
  83         support::make_test_thread(func5, std::move(p)).detach();
  84         assert(f.valid());
  85         f.wait();
  86         assert(f.valid());
  87         Clock::time_point t0 = Clock::now();
  88         f.wait();
  89         Clock::time_point t1 = Clock::now();
  90         assert(f.valid());
  91         assert(t1-t0 < ms(5));
  92     }
  93
  94   return 0;
  95 }