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libcxx/test/std/thread/futures/futures.async/async_race.pass.cpp

69 lines
1.7 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: libcpp-has-no-threads
// UNSUPPORTED: c++98, c++03
// <future>
// template <class F, class... Args>
// future<typename result_of<F(Args...)>::type>
// async(F&& f, Args&&... args);
// template <class F, class... Args>
// future<typename result_of<F(Args...)>::type>
// async(launch policy, F&& f, Args&&... args);
// This test is designed to cause and allow TSAN to detect the race condition
// reported in PR23293: https://bugs.llvm.org/show_bug.cgi?id=23293
#include <future>
#include <chrono>
#include <thread>
#include <memory>
#include <cassert>
int f_async() {
typedef std::chrono::milliseconds ms;
std::this_thread::sleep_for(ms(200));
return 42;
}
bool ran = false;
int f_deferred() {
ran = true;
return 42;
}
void test_each() {
{
std::future<int> f = std::async(f_async);
int const result = f.get();
assert(result == 42);
}
{
std::future<int> f = std::async(std::launch::async, f_async);
int const result = f.get();
assert(result == 42);
}
{
ran = false;
std::future<int> f = std::async(std::launch::deferred, f_deferred);
assert(ran == false);
int const result = f.get();
assert(ran == true);
assert(result == 42);
}
}
int main() {
for (int i=0; i < 25; ++i) test_each();
}