• 多线程学习笔记


    头文件windows.h

    创建线程 

    HANDLE CreateThread(
    LPSECURITY_ATTRIBUTES lpThreadAttributes,DWORD dwStackSize, 
    LPTHREAD_START_ROUTINE lpStartAddress, LPVOID lpParameter, 
    DWORD dwCreationFlags, 
    LPDWORD lpThreadId )

    该函数在其调用进程的进程空间里创建一个新的线程,并返回已建线程的句柄。 

    lpThreadAttributes:指向一个 SECURITY_ATTRIBUTES 结构的指针,该结构决定了线程的安全属性,一般置为 NULL;
    dwStackSize:指定了线程的堆栈深度,一般都设置为0;
    lpStartAddress:表示新线程开始执行时代码所在函数的地址,即线程的起始地址。一般情况为线程函数名;
    lpParameter:指定了线程执行时传送给线程的32位参数,即线程函数的参数;
    dwCreationFlags:控制线程创建的附加标志,可以取两种值。如果该参数为0,线程在被创建后就会立即开始执行;如果该参数为CREATE_SUSPENDED,则系统产生线程后,该线程处于挂起状态,并不马上执行,直至函数ResumeThread被调用;
    lpThreadId:该参数返回所创建线程的ID; 如果创建成功则返回线程的句柄,否则返回NULL

    SuspendThread(HANDLE hThread); 

    该函数用于挂起指定的线程,如果函数执行成功,则线程的执行被终止 .

    DWORD ResumeThread(HANDLE hThread); 

    该函数用于结束线程的挂起状态,执行线程。 

    VOID ExitThread(DWORD dwExitCode); 

    该函数用于线程终结自身的执行 

    BOOL TerminateThread(HANDLE hThread,DWORD dwExitCode); 

    强行终止某一线程的执行

    自己写的一个简易的线程类:

     1 #include <stdio.h>
     2 #include <windows.h>
     3 
     4 class unit {
     5 public:
     6     void *v;            //参数
     7     int *ret;            //返回值
     8 };
     9 
    10 class THREAD
    11 {
    12 public:
    13     HANDLE hThread;        //线程句柄
    14     DWORD ThreadID;        //线程id
    15     LPTHREAD_START_ROUTINE IpStartAddress;        //线程函数
    16     int ret;            //返回值
    17     unit u;                //将参数和返回值打包传入线程函数
    18     THREAD() {                            //初始化
    19         ret = 0;
    20     }
    21     THREAD(void *ThreadProcess) {        //带参数初始化
    22         ret = 0;
    23         IpStartAddress = (LPTHREAD_START_ROUTINE)ThreadProcess;
    24     }
    25     void run() {                        //运行线程    
    26         if (IpStartAddress != NULL) {
    27             u = { NULL,&ret };
    28             hThread = CreateThread(NULL, 0, IpStartAddress, (LPVOID)&u, 0, &ThreadID);
    29         }
    30     }
    31     void run(void *lp) {                //运行线程,并传入参数
    32         if (IpStartAddress != NULL) {
    33             u = { lp,&ret };
    34             hThread = CreateThread(NULL, 0, IpStartAddress, (LPVOID)&u, 0, &ThreadID);
    35         }
    36     }
    37 };

    该类可以调用带参数的线程函数或者不带参数的线程函数,线程函数返回值类型为int,将放在ret中

    使用:

    1 THREAD fightthread;    //创建线程类
    2 fightthread.IpStartAddress = (LPTHREAD_START_ROUTINE)waitFight;//线程函数赋值
    3 fightthread.run();        //运行线程

    线程函数定义:

    void waitFight(LPVOID pM) {    
        unit* c=(unit*)pM;    //参数类型为上边定义的unit类,类里的参数v可以是任意类型的参数
        函数体;
        ......
        unit->ret=0;    //线程函数返回值赋值
    }

    一个线程池的实现:

      1 #pragma warning(disable: 4530)
      2 #pragma warning(disable: 4786)
      3 #include <stdio.h>
      4 #include <cassert>
      5 #include <vector>
      6 #include <queue>
      7 #include <windows.h>
      8 using namespace std;
      9 
     10 class ThreadJob  //工作基类
     11 {
     12 public:
     13     //供线程池调用的虚函数
     14     virtual void DoJob(void *pPara) = 0;
     15 };
     16 
     17 class ThreadPool
     18 {
     19 public:
     20     //dwNum 线程池规模
     21     ThreadPool(DWORD dwNum = 4) : _lThreadNum(0), _lRunningNum(0)
     22     {
     23         InitializeCriticalSection(&_csThreadVector);
     24         InitializeCriticalSection(&_csWorkQueue);
     25         _EventComplete = CreateEvent(0, false, false, NULL);
     26         _EventEnd = CreateEvent(0, true, false, NULL);
     27         _SemaphoreCall = CreateSemaphore(0, 0, 0x7FFFFFFF, NULL);
     28         _SemaphoreDel = CreateSemaphore(0, 0, 0x7FFFFFFF, NULL);
     29         assert(_SemaphoreCall != INVALID_HANDLE_VALUE);
     30         assert(_EventComplete != INVALID_HANDLE_VALUE);
     31         assert(_EventEnd != INVALID_HANDLE_VALUE);
     32         assert(_SemaphoreDel != INVALID_HANDLE_VALUE);
     33         AdjustSize(dwNum <= 0 ? 4 : dwNum);
     34     }
     35     ~ThreadPool()
     36     {
     37         DeleteCriticalSection(&_csWorkQueue);
     38         CloseHandle(_EventEnd);
     39         CloseHandle(_EventComplete);
     40         CloseHandle(_SemaphoreCall);
     41         CloseHandle(_SemaphoreDel);
     42         vector<ThreadItem*>::iterator iter;
     43         for (iter = _ThreadVector.begin(); iter != _ThreadVector.end(); iter++)
     44         {
     45             if (*iter)
     46                 delete *iter;
     47         }
     48         DeleteCriticalSection(&_csThreadVector);
     49     }
     50     //调整线程池规模
     51     int AdjustSize(int iNum)
     52     {
     53         if (iNum > 0)
     54         {
     55             ThreadItem *pNew;
     56             EnterCriticalSection(&_csThreadVector);
     57             for (int _i = 0; _i<iNum; _i++)
     58             {
     59                 _ThreadVector.push_back(pNew = new ThreadItem(this));
     60                 assert(pNew);
     61                 pNew->_Handle = CreateThread(NULL, 0, DefaultJobProc, pNew, 0, NULL);
     62                 // set priority
     63                 SetThreadPriority(pNew->_Handle, THREAD_PRIORITY_BELOW_NORMAL);
     64                 assert(pNew->_Handle);
     65             }
     66             LeaveCriticalSection(&_csThreadVector);
     67         }
     68         else
     69         {
     70             iNum *= -1;
     71             ReleaseSemaphore(_SemaphoreDel, iNum > _lThreadNum ? _lThreadNum : iNum, NULL);
     72         }
     73         return (int)_lThreadNum;
     74     }
     75     //调用线程池
     76     void Call(void(*pFunc)(void  *), void *pPara = NULL)
     77     {
     78         assert(pFunc);
     79         EnterCriticalSection(&_csWorkQueue);
     80         _JobQueue.push(new JobItem(pFunc, pPara));
     81         LeaveCriticalSection(&_csWorkQueue);
     82         ReleaseSemaphore(_SemaphoreCall, 1, NULL);
     83     }
     84     //调用线程池
     85     inline void Call(ThreadJob * p, void *pPara = NULL)
     86     {
     87         Call(CallProc, new CallProcPara(p, pPara));
     88     }
     89     //结束线程池, 并同步等待
     90     bool EndAndWait(DWORD dwWaitTime = INFINITE)
     91     {
     92         SetEvent(_EventEnd);
     93         return WaitForSingleObject(_EventComplete, dwWaitTime) == WAIT_OBJECT_0;
     94     }
     95     //结束线程池
     96     inline void End()
     97     {
     98         SetEvent(_EventEnd);
     99     }
    100     inline DWORD Size()
    101     {
    102         return (DWORD)_lThreadNum;
    103     }
    104     inline DWORD GetRunningSize()
    105     {
    106         return (DWORD)_lRunningNum;
    107     }
    108     bool IsRunning()
    109     {
    110         return _lRunningNum > 0;
    111     }
    112 protected:
    113     //工作线程
    114     static DWORD WINAPI DefaultJobProc(LPVOID lpParameter = NULL)
    115     {
    116         ThreadItem *pThread = static_cast<ThreadItem*>(lpParameter);
    117         assert(pThread);
    118         ThreadPool *pThreadPoolObj = pThread->_pThis;
    119         assert(pThreadPoolObj);
    120         InterlockedIncrement(&pThreadPoolObj->_lThreadNum);
    121         HANDLE hWaitHandle[3];
    122         hWaitHandle[0] = pThreadPoolObj->_SemaphoreCall;
    123         hWaitHandle[1] = pThreadPoolObj->_SemaphoreDel;
    124         hWaitHandle[2] = pThreadPoolObj->_EventEnd;
    125         JobItem *pJob;
    126         bool fHasJob;
    127         for (;;)
    128         {
    129             DWORD wr = WaitForMultipleObjects(3, hWaitHandle, false, INFINITE);
    130             //响应删除线程信号
    131             if (wr == WAIT_OBJECT_0 + 1)
    132                 break;
    133             //从队列里取得用户作业
    134             EnterCriticalSection(&pThreadPoolObj->_csWorkQueue);
    135             if (fHasJob = !pThreadPoolObj->_JobQueue.empty())
    136             {
    137                 pJob = pThreadPoolObj->_JobQueue.front();
    138                 pThreadPoolObj->_JobQueue.pop();
    139                 assert(pJob);
    140             }
    141             LeaveCriticalSection(&pThreadPoolObj->_csWorkQueue);
    142             //受到结束线程信号 确定是否结束线程(结束线程信号 && 是否还有工作)
    143             if (wr == WAIT_OBJECT_0 + 2 && !fHasJob)
    144                 break;
    145             if (fHasJob && pJob)
    146             {
    147                 InterlockedIncrement(&pThreadPoolObj->_lRunningNum);
    148                 pThread->_dwLastBeginTime = GetTickCount();
    149                 pThread->_dwCount++;
    150                 pThread->_fIsRunning = true;
    151                 pJob->_pFunc(pJob->_pPara); //运行用户作业
    152                 delete pJob;
    153                 pThread->_fIsRunning = false;
    154                 InterlockedDecrement(&pThreadPoolObj->_lRunningNum);
    155             }
    156         }
    157         //删除自身结构
    158         EnterCriticalSection(&pThreadPoolObj->_csThreadVector);
    159         pThreadPoolObj->_ThreadVector.erase(find(pThreadPoolObj->_ThreadVector.begin(), pThreadPoolObj->_ThreadVector.end(), pThread));
    160         LeaveCriticalSection(&pThreadPoolObj->_csThreadVector);
    161         delete pThread;
    162         InterlockedDecrement(&pThreadPoolObj->_lThreadNum);
    163         if (!pThreadPoolObj->_lThreadNum)  //所有线程结束
    164             SetEvent(pThreadPoolObj->_EventComplete);
    165         return 0;
    166     }
    167     //调用用户对象虚函数
    168     static void CallProc(void *pPara)
    169     {
    170         CallProcPara *cp = static_cast<CallProcPara *>(pPara);
    171         assert(cp);
    172         if (cp)
    173         {
    174             cp->_pObj->DoJob(cp->_pPara);
    175             delete cp;
    176         }
    177     }
    178     //用户对象结构
    179     struct CallProcPara
    180     {
    181         ThreadJob* _pObj;//用户对象 
    182         void *_pPara;//用户参数
    183         CallProcPara(ThreadJob* p, void *pPara) : _pObj(p), _pPara(pPara) { };
    184     };
    185     //用户函数结构
    186     struct JobItem
    187     {
    188         void(*_pFunc)(void  *);//函数
    189         void *_pPara; //参数
    190         JobItem(void(*pFunc)(void  *) = NULL, void *pPara = NULL) : _pFunc(pFunc), _pPara(pPara) { };
    191     };
    192     //线程池中的线程结构
    193     struct ThreadItem
    194     {
    195         HANDLE _Handle; //线程句柄
    196         ThreadPool *_pThis;  //线程池的指针
    197         DWORD _dwLastBeginTime; //最后一次运行开始时间
    198         DWORD _dwCount; //运行次数
    199         bool _fIsRunning;
    200         ThreadItem(ThreadPool *pthis) : _pThis(pthis), _Handle(NULL), _dwLastBeginTime(0), _dwCount(0), _fIsRunning(false) { };
    201         ~ThreadItem()
    202         {
    203             if (_Handle)
    204             {
    205                 CloseHandle(_Handle);
    206                 _Handle = NULL;
    207             }
    208         }
    209     };
    210     std::queue<JobItem *> _JobQueue;  //工作队列
    211     std::vector<ThreadItem *>  _ThreadVector; //线程数据
    212     CRITICAL_SECTION _csThreadVector, _csWorkQueue; //工作队列临界, 线程数据临界
    213     HANDLE _EventEnd, _EventComplete, _SemaphoreCall, _SemaphoreDel;//结束通知, 完成事件, 工作信号, 删除线程信号
    214     long _lThreadNum, _lRunningNum; //线程数, 运行的线程数
    215 };
    ThreadPool Code

    使用:

    ThreadPool tp(10);
    tp.Call(函数名[,函数参数]);
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  • 原文地址:https://www.cnblogs.com/chengyu404/p/5425362.html
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