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
|
// Copyright (C) 2001-2003
// William E. Kempf
//
// 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)
#define BOOST_THREAD_PROVIDES_ONCE_CXX11
#include <boost/thread/thread.hpp>
#include <boost/thread/once.hpp>
#include <cassert>
int value=0;
#ifdef BOOST_THREAD_PROVIDES_ONCE_CXX11
static boost::once_flag once;
//static boost::once_flag once2 = BOOST_ONCE_INIT;
#else
static boost::once_flag once = BOOST_ONCE_INIT;
//static boost::once_flag once2 = once;
#endif
void init()
{
++value;
}
void thread_proc()
{
boost::call_once(&init, once);
}
int main()
{
boost::thread_group threads;
for (int i=0; i<5; ++i)
threads.create_thread(&thread_proc);
threads.join_all();
assert(value == 1);
}
|
