87 lines
2.1 KiB
C++
87 lines
2.1 KiB
C++
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//===----------------------------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// <future>
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// class future<R>
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// void wait() const;
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#include <future>
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#include <cassert>
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void func1(std::promise<int>& p)
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{
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std::this_thread::sleep_for(std::chrono::milliseconds(500));
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p.set_value(3);
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}
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int j = 0;
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void func3(std::promise<int&>& p)
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{
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std::this_thread::sleep_for(std::chrono::milliseconds(500));
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j = 5;
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p.set_value(j);
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}
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void func5(std::promise<void>& p)
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{
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std::this_thread::sleep_for(std::chrono::milliseconds(500));
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p.set_value();
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}
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int main()
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{
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typedef std::chrono::high_resolution_clock Clock;
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typedef std::chrono::duration<double, std::milli> ms;
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{
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typedef int T;
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std::promise<T> p;
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std::future<T> f = p.get_future();
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std::thread(func1, std::move(p)).detach();
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assert(f.valid());
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f.wait();
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assert(f.valid());
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Clock::time_point t0 = Clock::now();
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f.wait();
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Clock::time_point t1 = Clock::now();
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assert(f.valid());
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assert(t1-t0 < ms(5));
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}
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{
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typedef int& T;
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std::promise<T> p;
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std::future<T> f = p.get_future();
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std::thread(func3, std::move(p)).detach();
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assert(f.valid());
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f.wait();
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assert(f.valid());
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Clock::time_point t0 = Clock::now();
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f.wait();
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Clock::time_point t1 = Clock::now();
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assert(f.valid());
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assert(t1-t0 < ms(5));
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}
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{
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typedef void T;
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std::promise<T> p;
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std::future<T> f = p.get_future();
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std::thread(func5, std::move(p)).detach();
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assert(f.valid());
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f.wait();
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assert(f.valid());
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Clock::time_point t0 = Clock::now();
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f.wait();
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Clock::time_point t1 = Clock::now();
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assert(f.valid());
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assert(t1-t0 < ms(5));
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}
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}
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