修改BOOST(一)

boost是个不错的库。可是也不算太成熟。例如，boost的处理TLS是通过boost_threadmon.dll，使用了TLS的代码必须带一个动态链接库；其次库也不能自动安装，也不能根据你的程序选择了什么样的链接方式(如MT,MD)选择库，如果每次编写一个小型的测试程序都要设置很多东西，恐怕太费力气了；第三，缺乏一些常用的功能，如事件，读写锁等。今天我要设置的是使得你在VC下只需要设置MT或MD方式(链接到多线程动态链接和静态连接库)就可以使用boost。其次是将boost_threadmon.dll合并到libboost_thread.lib库中。『本人刚学boost才4天，说错了恐怕在所难免，请指正。本文中使用的版本为1.28.0』

boost多线程库包括两个，一个是boost_threadmon.dll，是个动态连接库，另一个为libboost_thread.lib，是个静态链接库。为什么要用两个呢？主要是为了清除TLS中的数据。在boost_threadmon.dll加载的时候，动态链接库收到消息DLL_PROCESS_ATTACH，这时它分配一个TLS和关键代码段CriticalSection。在用户程序创建线程的时候，收到DLL_THREAD_ATTACH，这时将该线程的TLS数据清除。当主程序退出的时候，收到DLL_PROCESS_DETACH，这时动态链接库清除主线程的TLS数据。

Boost管理TLS如下：当用户设置TLS数据时，boost将该数据指针和一个清理函数放置到一个cleanup_info的结构中，并将它设置到一个cleanup_handler的map中。cleanup_info第一个成员为清理函数指针，第二个成员为数据指针本身。而cleanup_handler则以TLS索引为key，以cleanup_info为data项内部的一个TLS索引对应着一个cleanup_handlers指针，而该指针中的数据都是用户分配的TLS和对应的数据指针以及释放函数。Boost又使用on_thread_exit(&cleanup)函数将cleanup_handlers安装到boost_threadmon.dll中的TLS索引上。

涉及的tss.cpp中的结构如下：

typedef std::pair<void(*)(void*), void*> cleanup_info;

typedef std::map<int, cleanup_info> cleanup_handlers;

涉及的threadmon.cpp中的结构如下：

typedef void (__cdecl * handler)(void);

typedef std::list<handler> exit_handlers;

typedef std::set<exit_handlers*> registered_handlers;

上面可能我根本没有说清楚，可是我不想再打太多的字了，下面直接修改：

1． Thread.hpp文件开头修改为：

#ifndef BOOST_THREAD_WEK070601_HPP

#define BOOST_THREAD_WEK070601_HPP

////////////////////////////////////////////////////////////////////////////

·monitor库：使用/MT boost_mon_libmt.lib thread:boost_thread_libmt.lib

·monitor库：使用/MTD boost_mon_libmtd.lib thread:boost_thread_libmtd.lib

·monitor库：使用/MD boost_mon_libmd.lib thread:boost_thread_libmd.lib

·monitor库：使用/MDD boost_mon_libmdd.lib thread:boost_thread_libmdd.lib

·monitor-thread合并库：使用/MT boost_thread_mon_libmt.lib

·monitor-thread合并库：使用/MTD boost_thread_mon_libmtd.lib

·monitor-thread合并库：使用/MD boost_thread_mon_libmd.lib

·monitor-thread合并库：使用/MDD boost_thread_mon_libmdd.lib

#ifdef WIN32

#ifndef _MT

#error ERROR: Must compiled with multithread dll!

#endif

#define BOOST_HAS_THREADS

#ifndef BOOST_THREADMON_AS_DLL

#ifdef _DEBUG

#ifdef _DLL

#pragma comment( lib, "boost_thread_mon_libmdd.lib")

#else

#pragma comment( lib, "boost_thread_mon_libmtd.lib")

#endif

#else

#ifdef _DLL

#pragma comment( lib, "boost_thread_mon_libmd.lib")

#else

#pragma comment( lib, "boost_thread_mon_libmt.lib")

#endif

#else

#ifdef _DEBUG

#ifdef _DLL

#pragma comment( lib, "boost_mon_libmdd.lib")

#pragma comment( lib, "boost_thread_libmdd.lib")

#else

#pragma comment( lib, "boost_mon_libmtd.lib")

#pragma comment( lib, "boost_thread_libmtd.lib")

#endif

#else

#ifdef _DLL

#pragma comment( lib, "boost_mon_libmd.lib")

#pragma comment( lib, "boost_thread_libmd.lib")

#else

#pragma comment( lib, "boost_mon_libmt.lib")

#pragma comment( lib, "boost_thread_libmt.lib")

#endif

//////////////////////////////////////////////////////////////////////////////////

#include <boost/config.hpp>

#ifndef BOOST_HAS_THREADS

# error Thread support is unavailable!

#endif

2． Threadmon.hpp文件修改为：

///////////////////////////////////////////////////////////////////////////

//2002.5.30修改。

#ifdef BOOST_THREADMON_AS_DLL

#ifdef BOOST_THREADMON_EXPORTS

#define BOOST_THREADMON_API __declspec(dllexport)

#else

#define BOOST_THREADMON_API __declspec(dllimport)

#endif

#else

#define BOOST_THREADMON_API

#endif

extern "C" BOOST_THREADMON_API int on_thread_exit(void (__cdecl * func)(void));

extern "C" BOOST_THREADMON_API void on_thread_detach();

3． Threadmon.cpp文件修改为：

///////////////////////////////////////////////////////////////////

//This File has been modified!

// threadmon.cpp : Defines the entry point for the DLL application.

////////////////////////////////////////////////////////

//2002.5.30.modified.

#ifdef BOOST_THREADMON_AS_DLL

#define BOOST_THREADMON_EXPORTS

#else

#include <boost/thread/once.hpp>

#endif//BOOST_THREADMON_AS_DLL

////////////////////////////////////////////////////////

#include "threadmon.hpp"

#ifdef BOOST_HAS_WINTHREADS

#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers

#include <windows.h>

#ifdef BOOST_MSVC

# pragma warning(disable : 4786)

#endif

#include <list>

#include <set>

#include <algorithm>

typedef void (__cdecl * handler)(void);

typedef std::list<handler> exit_handlers;

typedef std::set<exit_handlers*> registered_handlers;

namespace

{

CRITICAL_SECTION cs;

DWORD key;

registered_handlers registry;

}

void on_process_attach()

{

InitializeCriticalSection(&cs);

key = TlsAlloc();

}

void on_process_detach()

{

on_thread_detach();

// Destroy any remaining exit handlers. Above we assumed there'd only be the main

// thread left, but to insure we don't get memory leaks we won't make that assumption

// here.

EnterCriticalSection(&cs);

for (registered_handlers::iterator it = registry.begin();

it != registry.end(); ++it)

{

#ifndef BOOST_THREADMON_AS_DLL

for (exit_handlers::iterator p = (*it)->begin(); p != (*it)->end(); ++p)

(*p)();

#endif

delete (*it);

}

LeaveCriticalSection(&cs);

DeleteCriticalSection(&cs);

TlsFree(key);

}

#ifdef BOOST_THREADMON_AS_DLL

#if defined(__BORLANDC__)

#define DllMain DllEntryPoint

#endif

extern "C"

BOOL WINAPI DllMain(HANDLE module, DWORD reason, LPVOID)

{

switch (reason)

{

case DLL_PROCESS_ATTACH:

on_process_attach();

break;

case DLL_THREAD_ATTACH:

break;

case DLL_THREAD_DETACH:

on_thread_detach();

break;

case DLL_PROCESS_DETACH:

on_process_detach();

break;

}

return TRUE;

}

#else//BOOST_THREADMON_AS_DLL

boost::once_flag once = BOOST_ONCE_INIT;

class process_envelope

{

process_envelope()

{

boost::call_once(&on_process_attach, once);

}

public:

~process_envelope(){on_process_detach();}

static process_envelope *get()

{

static process_envelope p;

return &p;

}

};

#endif//!BOOST_THREADMON_AS_DLL

void on_thread_detach()

{

// Call the thread's exit handlers.

#ifndef BOOST_THREADMON_AS_DLL

process_envelope::get();

#endif

exit_handlers* handlers = static_cast<exit_handlers*>(TlsGetValue(key));

if (handlers)

{

for (exit_handlers::iterator it = handlers->begin(); it != handlers->end(); ++it)

(*it)();

// Remove the exit handler list from the registered lists and then destroy it.

EnterCriticalSection(&cs);

registry.erase(handlers);

LeaveCriticalSection(&cs);

delete handlers;

}

int on_thread_exit(void (__cdecl * func)(void))

{

#ifndef BOOST_THREADMON_AS_DLL

process_envelope::get();

#endif

// Get the exit handlers for the current thread, creating and registering

// one if it doesn't exist.

exit_handlers* handlers = static_cast<exit_handlers*>(TlsGetValue(key));

if (!handlers)

{

try

{

handlers = new exit_handlers;

// Handle "broken" implementations of operator new that don't throw.

if (!handlers)

return -1;

}

catch (...)

{

return -1;

}

// Attempt to set a TLS value for the new handlers.

if (!TlsSetValue(key, handlers))

{

delete handlers;

return -1;

}

// Attempt to register this new handler so that memory can be properly

// cleaned up.

try

{

EnterCriticalSection(&cs);

registry.insert(handlers);

LeaveCriticalSection(&cs);

}

catch (...)

{

LeaveCriticalSection(&cs);

delete handlers;

return -1;

}

// Attempt to add the handler to the list of exit handlers. If it's been previously

// added just report success and exit.

try

{

handlers->push_front(func);

}

catch (...)

{

return -1;

}

return 0;

}

#endif // BOOST_HAS_WINTHREADS

4． Thread.cpp文件修改为：

在#include "timeconv.inl"行后：

////////////////////////////////////////////////////////////////////////

//2002.5.30;修改

#ifdef WIN32

#ifndef BOOST_THREADMON_AS_DLL

#include "threadmon.hpp"

#endif

////////////////////////////////////////////////////////////////////////

修改thread_proxy(void* param)方法的尾部为：

////////////////////////////////////////////////////////////////////////

//2002.5.30;修改

#ifdef WIN32

#ifndef BOOST_THREADMON_AS_DLL

on_thread_detach();

#endif

////////////////////////////////////////////////////////////////////////

5．将<boost>\libs\thread\src目录下的所有文件插入到自己新建的工程中，按上面的thread.hpp头文件中的库名分别生成不同的库文件，将这些库文件拷贝到VC目录下，以后编译使用了boost.thread的工程时，再也不需要任何设置了。