shared_ptr_mt_test.cpp

C++的一个好库。。。现在很流行

#include <boost/config.hpp>

#if defined(BOOST_MSVC)
#pragma warning(disable: 4786)  // identifier truncated in debug info
#pragma warning(disable: 4710)  // function not inlined
#pragma warning(disable: 4711)  // function selected for automatic inline expansion
#pragma warning(disable: 4514)  // unreferenced inline removed
#endif

//
//  shared_ptr_mt_test.cpp - tests shared_ptr with multiple threads
//
//  Copyright (c) 2002 Peter Dimov and Multi Media Ltd.
//
// 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)
//

#include <boost/shared_ptr.hpp>
#include <boost/bind.hpp>

#include <vector>
#include <memory>
#include <stdexcept>

#include <cstdio>
#include <ctime>

// 'portable' thread framework

class abstract_thread
{
public:

    virtual ~abstract_thread() {}
    virtual void run() = 0;
};

#if !defined(BOOST_HAS_PTHREADS) && defined(BOOST_HAS_WINTHREADS)

char const * title = "Using Windows threads";

#include <windows.h>
#include <process.h>

typedef HANDLE pthread_t;

unsigned __stdcall common_thread_routine(void * pv)
{
    abstract_thread * pt = static_cast<abstract_thread *>(pv);
    pt->run();
    delete pt;
    return 0;
}

int pthread_create(pthread_t * thread, void const *, unsigned (__stdcall * start_routine) (void*), void* arg)
{
    HANDLE h = (HANDLE)_beginthreadex(0, 0, start_routine, arg, 0, 0);

    if(h != 0)
    {
        *thread = h;
        return 0;
    }
    else
    {
        return 1; // return errno;
    }
}

int pthread_join(pthread_t thread, void ** /*value_ptr*/)
{
    ::WaitForSingleObject(thread, INFINITE);
    ::CloseHandle(thread);
    return 0;
}

#else

char const * title = "Using POSIX threads";

#include <pthread.h>

extern "C" void * common_thread_routine(void * pv)
{
    abstract_thread * pt = static_cast<abstract_thread *>(pv);
    pt->run();
    delete pt;
    return 0;
}

#endif

//

template<class F> class thread: public abstract_thread
{
public:

    explicit thread(F f): f_(f)
    {
    }

    void run()
    {
        f_();
    }

private:

    F f_;
};

template<class F> pthread_t createThread(F f)
{
    std::auto_ptr<abstract_thread> p(new thread<F>(f));

    pthread_t r;

    if(pthread_create(&r, 0, common_thread_routine, p.get()) == 0)
    {
        p.release();
        return r;
    }

    throw std::runtime_error("createThread failed.");
}

//

int const n = 1024 * 1024;

void test(boost::shared_ptr<int> const & pi)
{
    std::vector< boost::shared_ptr<int> > v;

    for(int i = 0; i < n; ++i)
    {
        v.push_back(pi);
    }
}

int const m = 16; // threads

int main()
{
    using namespace std; // printf, clock_t, clock

    printf("%s: %d threads, %d iterations: ", title, m, n);

    boost::shared_ptr<int> pi(new int(42));

    clock_t t = clock();

    pthread_t a[m];

    for(int i = 0; i < m; ++i)
    {
        a[i] = createThread( boost::bind(test, pi) );
    }

    for(int j = 0; j < m; ++j)
    {
        pthread_join(a[j], 0);
    }

    t = clock() - t;

    printf("\n\n%.3f seconds.\n", static_cast<double>(t) / CLOCKS_PER_SEC);

    return 0;
}