1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
// Copyright (C) 2013 Vicente Botet
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// futtest.cpp
#include <iostream>
#define BOOST_THREAD_VERSION 4
#include <boost/thread/future.hpp>
#include <boost/thread/thread.hpp>
#include <boost/bind/bind.hpp>
#include <boost/chrono.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/scoped_ptr.hpp>
typedef boost::shared_ptr< boost::promise<int> > IntPromise;
void foo(IntPromise p)
{
std::cout << "foo" << std::endl;
p->set_value(123); // This line locks the future's mutex, then calls the continuation with the mutex already locked.
}
void bar(boost::future<int> fooResult)
{
try {
std::cout << "bar" << std::endl;
int i = fooResult.get(); // Code hangs on this line (Due to future already being locked by the set_value call)
std::cout << "i: " << i << std::endl;
} catch(...) {
std::cout << __FILE__ << ":" << __LINE__ << std::endl;
}
}
int main()
{
std::cout << __FILE__ << ":" << __LINE__ << std::endl;
try {
IntPromise p(new boost::promise<int>());
boost::thread t(boost::bind(foo, p));
boost::future<int> f1 = p->get_future();
f1.then(boost::launch::deferred, &bar);
t.join();
} catch(...) {
return 1;
}
std::cout << __FILE__ << ":" << __LINE__ << std::endl;
try {
IntPromise p(new boost::promise<int>());
boost::thread t(boost::bind(foo, p));
boost::future<int> f1 = p->get_future();
f1.then(boost::launch::async, &bar);
t.join();
} catch(...) {
return 2;
}
std::cout << __FILE__ << ":" << __LINE__ << std::endl;
}
|
