简单的线程池

      一个简单的线程池的实现，基本原理：创建线程池的时候即创建多个线程，且让它们处于挂起状态，然后等待用户需要创建一个线程的时候，恢复其中一个被挂起的线程，并执行用户指定的线程函数。执行完毕后再次挂起这个线程，直到用户再次需要创建新的线程的时候，再恢复一个挂起的线程。最后程序退出，关闭所有线程。

 

ThreadPool 头文件：

#ifndef __ThreadPool_h__#define __ThreadPool_h__#include <Windows.h>typedef unsigned int (__stdcall *PTHREADFUNC)(void*);typedef enum _thread_state {TS_RUNNING, TS_SUSPENDED, TS_FINISHED} ThreadState;typedef struct _thread_info {HANDLE_Handle;DWORD_Id;DWORD_ExitCode;ThreadState_State;PTHREADFUNC_ThrdFunc;void*_Param;} ThreadInfo;class CThreadPool{public:CThreadPool( long nMaxCount );~CThreadPool();boolCreate();voidDestroy();boolIsRunning() { return _IsCreated; }intCreateThread( PTHREADFUNC pThrdFunc, void *pParam, ULONG flag );voidResumeThread( int index );voidSuspendThread( int index );voidEndThread( int index );private:bool_IsCreated;long_MaxCount;long_CurIndex;ThreadInfo*_ThreadList;CRITICAL_SECTION_CS;static voidResetThrdInfo( ThreadInfo *pThrdInfo );static unsigned int __stdcallDefThrdFunc( void *pParam );int GetThread() {int i;for( i = _CurIndex; i < _MaxCount; i++ ) {if( _ThreadList[i]._State == TS_FINISHED ) {_CurIndex = (i + 1) % _MaxCount;return i;}}for( i = 0; i < _CurIndex; i++ ) {if( _ThreadList[i]._State == TS_FINISHED ) {_CurIndex = (i + 1) % _MaxCount;return i;}}return -1;}};#endif // __ThreadPool_h__

 

ThreadPool 源文件：

#include "ThreadPool.h"unsigned int __stdcall CThreadPool::DefThrdFunc( void *pParam ){ThreadInfo *pThrdInfo = (ThreadInfo*)pParam;if( NULL != pThrdInfo ) {while( 1 ) {if( TS_RUNNING == pThrdInfo->_State ) {pThrdInfo->_ThrdFunc( pThrdInfo->_Param );ResetThrdInfo( pThrdInfo );}}}return 0;}void CThreadPool::ResetThrdInfo( ThreadInfo *pThrdInfo ){if( NULL != pThrdInfo ) {pThrdInfo->_State= TS_FINISHED;pThrdInfo->_ThrdFunc= DefThrdFunc;pThrdInfo->_Param= NULL;pThrdInfo->_ExitCode= 0;::SuspendThread( pThrdInfo->_Handle );}}CThreadPool::CThreadPool( long nMaxCount ): _MaxCount(nMaxCount),_CurIndex(-1),_IsCreated(false),_ThreadList(NULL){}CThreadPool::~CThreadPool(){if( _IsCreated )Destroy();}bool CThreadPool::Create(){if( _IsCreated )return true;InitializeCriticalSection( &_CS );_ThreadList = new ThreadInfo[_MaxCount];memset( _ThreadList, 0, sizeof(ThreadInfo) * _MaxCount );_IsCreated = true;for( int i = 0; i < _MaxCount; i++ ) {DWORD dwId;HANDLE h = ::CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)DefThrdFunc, &_ThreadList[i],CREATE_SUSPENDED, &dwId );if( NULL == h ) {Destroy();return false;}else {EnterCriticalSection( &_CS );_ThreadList[i]._ThrdFunc= DefThrdFunc;_ThreadList[i]._Param= NULL;_ThreadList[i]._Handle= h;_ThreadList[i]._Id= dwId;_ThreadList[i]._State= TS_FINISHED;_ThreadList[i]._ExitCode= 0;LeaveCriticalSection( &_CS );}}_CurIndex = 0;return true;}void CThreadPool::Destroy(){if( !_IsCreated || NULL == _ThreadList )return;EnterCriticalSection( &_CS );for( int i = 0; i < _MaxCount; i++ ) {if( _ThreadList[i]._Handle ) {TerminateThread( _ThreadList[i]._Handle, _ThreadList[i]._ExitCode );CloseHandle( _ThreadList[i]._Handle );}}LeaveCriticalSection( &_CS );_IsCreated= false;_MaxCount= 0;_CurIndex= -1;delete []_ThreadList;_ThreadList = NULL;DeleteCriticalSection( &_CS );}int CThreadPool::CreateThread( PTHREADFUNC pThrdFunc, void *pParam, ULONG flag ){if( NULL == pThrdFunc )return NULL;int index = GetThread();if( index < 0 )return -1;EnterCriticalSection( &_CS );_ThreadList[index]._ThrdFunc= pThrdFunc;_ThreadList[index]._Param= pParam;if( CREATE_SUSPENDED == flag )_ThreadList[index]._State= TS_SUSPENDED;else {_ThreadList[index]._State= TS_RUNNING;::ResumeThread( _ThreadList[index]._Handle );}LeaveCriticalSection( &_CS );return index;}void CThreadPool::ResumeThread( int index ){if( index < 0 || index >= _MaxCount )return;if( NULL != _ThreadList ) {if( TS_SUSPENDED == _ThreadList[index]._State )::ResumeThread( _ThreadList[index]._Handle );}}void CThreadPool::SuspendThread( int index ){if( index < 0 || index >= _MaxCount )return;if( NULL != _ThreadList ) {if( TS_RUNNING == _ThreadList[index]._State )::SuspendThread( _ThreadList[index]._Handle );}}void CThreadPool::EndThread( int index ){if( index < 0 || index >= _MaxCount )return;if( NULL == _ThreadList )return;if( TS_RUNNING == _ThreadList[index]._State )::SuspendThread( _ThreadList[index]._Handle );EnterCriticalSection( &_CS );_ThreadList[index]._State= TS_FINISHED;_ThreadList[index]._ThrdFunc= DefThrdFunc;_ThreadList[index]._Param= NULL;LeaveCriticalSection( &_CS );}

 

测试代码：

#include "ThreadPool.h"#include <stdio.h>unsigned int __stdcall thread_proc1( void *param ){int *pindex = (int*)param;printf( "thread_proc1: thread %d running .../r/n", *pindex );return 0;}unsigned int __stdcall thread_proc2( void *param ){int *pindex = (int*)param;printf( "thread_proc2: thread %d running .../r/n", *pindex );return 0;}unsigned int __stdcall thread_proc3( void *param ){int *pindex = (int*)param;printf( "thread_proc3: thread %d running .../r/n", *pindex );return 0;}int main( void ){CThreadPool pool( 12 );if( !pool.Create() )return 1;int arr[30] = { 0 };int i;for( i = 0; i < 30; i++ )arr[i] = i + 1;for( i = 0; i < 10; i++ )pool.CreateThread( (PTHREADFUNC)thread_proc1, (void*)&arr[i], 0 );Sleep( 300 );for( i = 10; i < 20; i++ )pool.CreateThread( (PTHREADFUNC)thread_proc2, (void*)&arr[i], 0 );Sleep( 1000 );for( i = 20; i < 30; i++ )pool.CreateThread( (PTHREADFUNC)thread_proc3, (void*)&arr[i], 0 );Sleep( 2000 );pool.Destroy();return 0;}

 

执行结果：

thread_proc1: thread 1 running ...thread_proc1: thread 2 running ...thread_proc1: thread 4 running ...thread_proc1: thread 6 running ...thread_proc1: thread 3 running ...thread_proc1: thread 8 running ...thread_proc1: thread 10 running ...thread_proc1: thread 5 running ...thread_proc1: thread 7 running ...thread_proc1: thread 9 running ...thread_proc2: thread 14 running ...thread_proc2: thread 11 running ...thread_proc2: thread 13 running ...thread_proc2: thread 15 running ...thread_proc2: thread 12 running ...thread_proc2: thread 17 running ...thread_proc2: thread 19 running ...thread_proc2: thread 16 running ...thread_proc2: thread 18 running ...thread_proc2: thread 20 running ...thread_proc3: thread 21 running ...thread_proc3: thread 22 running ...thread_proc3: thread 23 running ...thread_proc3: thread 25 running ...thread_proc3: thread 27 running ...thread_proc3: thread 29 running ...thread_proc3: thread 24 running ...thread_proc3: thread 26 running ...thread_proc3: thread 28 running ...thread_proc3: thread 30 running ...请按任意键继续. . .