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：

#include <stdio.h>
#include <windows.h>

class unit {
public:
void *v;            //参数
int *ret;            //返回值
};

class THREAD
{
public:
HANDLE hThread;        //线程句柄
DWORD ThreadID;        //线程id
LPTHREAD_START_ROUTINE IpStartAddress;        //线程函数
int ret;            //返回值
unit u;                //将参数和返回值打包传入线程函数
THREAD() {                            //初始化
ret = 0;
}
THREAD(void *ThreadProcess) {        //带参数初始化
ret = 0;
IpStartAddress = (LPTHREAD_START_ROUTINE)ThreadProcess;
}
void run() {                        //运行线程
if (IpStartAddress != NULL) {
u = { NULL,&ret };
hThread = CreateThread(NULL, 0, IpStartAddress, (LPVOID)&u, 0, &ThreadID);
}
}
void run(void *lp) {                //运行线程，并传入参数
if (IpStartAddress != NULL) {
u = { lp,&ret };
hThread = CreateThread(NULL, 0, IpStartAddress, (LPVOID)&u, 0, &ThreadID);
}
}
};

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：

THREAD fightthread;    //创建线程类
fightthread.IpStartAddress = (LPTHREAD_START_ROUTINE)waitFight;//线程函数赋值
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：

#pragma warning(disable: 4530)
#pragma warning(disable: 4786)
#include <stdio.h>
#include <cassert>
#include <vector>
#include <queue>
#include <windows.h>
using namespace std;

class ThreadJob  //工作基类
{
public:
//供线程池调用的虚函数
virtual void DoJob(void *pPara) = 0;
};

class ThreadPool
{
public:
//dwNum 线程池规模
ThreadPool(DWORD dwNum = 4) : _lThreadNum(0), _lRunningNum(0)
{
InitializeCriticalSection(&_csThreadVector);
InitializeCriticalSection(&_csWorkQueue);
_EventComplete = CreateEvent(0, false, false, NULL);
_EventEnd = CreateEvent(0, true, false, NULL);
_SemaphoreCall = CreateSemaphore(0, 0, 0x7FFFFFFF, NULL);
_SemaphoreDel = CreateSemaphore(0, 0, 0x7FFFFFFF, NULL);
assert(_SemaphoreCall != INVALID_HANDLE_VALUE);
assert(_EventComplete != INVALID_HANDLE_VALUE);
assert(_EventEnd != INVALID_HANDLE_VALUE);
assert(_SemaphoreDel != INVALID_HANDLE_VALUE);
AdjustSize(dwNum <= 0 ? 4 : dwNum);
}
~ThreadPool()
{
DeleteCriticalSection(&_csWorkQueue);
CloseHandle(_EventEnd);
CloseHandle(_EventComplete);
CloseHandle(_SemaphoreCall);
CloseHandle(_SemaphoreDel);
vector<ThreadItem*>::iterator iter;
for (iter = _ThreadVector.begin(); iter != _ThreadVector.end(); iter++)
{
if (*iter)
delete *iter;
}
DeleteCriticalSection(&_csThreadVector);
}
//调整线程池规模
int AdjustSize(int iNum)
{
if (iNum > 0)
{
ThreadItem *pNew;
EnterCriticalSection(&_csThreadVector);
for (int _i = 0; _i<iNum; _i++)
{
_ThreadVector.push_back(pNew = new ThreadItem(this));
assert(pNew);
pNew->_Handle = CreateThread(NULL, 0, DefaultJobProc, pNew, 0, NULL);
// set priority
SetThreadPriority(pNew->_Handle, THREAD_PRIORITY_BELOW_NORMAL);
assert(pNew->_Handle);
}
LeaveCriticalSection(&_csThreadVector);
}
else
{
iNum *= -1;
ReleaseSemaphore(_SemaphoreDel, iNum > _lThreadNum ? _lThreadNum : iNum, NULL);
}
return (int)_lThreadNum;
}
//调用线程池
void Call(void(*pFunc)(void  *), void *pPara = NULL)
{
assert(pFunc);
EnterCriticalSection(&_csWorkQueue);
_JobQueue.push(new JobItem(pFunc, pPara));
LeaveCriticalSection(&_csWorkQueue);
ReleaseSemaphore(_SemaphoreCall, 1, NULL);
}
//调用线程池
inline void Call(ThreadJob * p, void *pPara = NULL)
{
Call(CallProc, new CallProcPara(p, pPara));
}
//结束线程池, 并同步等待
bool EndAndWait(DWORD dwWaitTime = INFINITE)
{
SetEvent(_EventEnd);
return WaitForSingleObject(_EventComplete, dwWaitTime) == WAIT_OBJECT_0;
}
//结束线程池
inline void End()
{
SetEvent(_EventEnd);
}
inline DWORD Size()
{
return (DWORD)_lThreadNum;
}
inline DWORD GetRunningSize()
{
return (DWORD)_lRunningNum;
}
bool IsRunning()
{
return _lRunningNum > 0;
}
protected:
//工作线程
static DWORD WINAPI DefaultJobProc(LPVOID lpParameter = NULL)
{
ThreadItem *pThread = static_cast<ThreadItem*>(lpParameter);
assert(pThread);
ThreadPool *pThreadPoolObj = pThread->_pThis;
assert(pThreadPoolObj);
InterlockedIncrement(&pThreadPoolObj->_lThreadNum);
HANDLE hWaitHandle[3];
hWaitHandle[0] = pThreadPoolObj->_SemaphoreCall;
hWaitHandle[1] = pThreadPoolObj->_SemaphoreDel;
hWaitHandle[2] = pThreadPoolObj->_EventEnd;
JobItem *pJob;
bool fHasJob;
for (;;)
{
DWORD wr = WaitForMultipleObjects(3, hWaitHandle, false, INFINITE);
//响应删除线程信号
if (wr == WAIT_OBJECT_0 + 1)
break;
//从队列里取得用户作业
EnterCriticalSection(&pThreadPoolObj->_csWorkQueue);
if (fHasJob = !pThreadPoolObj->_JobQueue.empty())
{
pJob = pThreadPoolObj->_JobQueue.front();
pThreadPoolObj->_JobQueue.pop();
assert(pJob);
}
LeaveCriticalSection(&pThreadPoolObj->_csWorkQueue);
//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)
if (wr == WAIT_OBJECT_0 + 2 && !fHasJob)
break;
if (fHasJob && pJob)
{
InterlockedIncrement(&pThreadPoolObj->_lRunningNum);
pThread->_dwLastBeginTime = GetTickCount();
pThread->_dwCount++;
pThread->_fIsRunning = true;
pJob->_pFunc(pJob->_pPara); //运行用户作业
delete pJob;
pThread->_fIsRunning = false;
InterlockedDecrement(&pThreadPoolObj->_lRunningNum);
}
}
//删除自身结构
EnterCriticalSection(&pThreadPoolObj->_csThreadVector);
pThreadPoolObj->_ThreadVector.erase(find(pThreadPoolObj->_ThreadVector.begin(), pThreadPoolObj->_ThreadVector.end(), pThread));
LeaveCriticalSection(&pThreadPoolObj->_csThreadVector);
delete pThread;
InterlockedDecrement(&pThreadPoolObj->_lThreadNum);
if (!pThreadPoolObj->_lThreadNum)  //所有线程结束
SetEvent(pThreadPoolObj->_EventComplete);
return 0;
}
//调用用户对象虚函数
static void CallProc(void *pPara)
{
CallProcPara *cp = static_cast<CallProcPara *>(pPara);
assert(cp);
if (cp)
{
cp->_pObj->DoJob(cp->_pPara);
delete cp;
}
}
//用户对象结构
struct CallProcPara
{
ThreadJob* _pObj;//用户对象
void *_pPara;//用户参数
CallProcPara(ThreadJob* p, void *pPara) : _pObj(p), _pPara(pPara) { };
};
//用户函数结构
struct JobItem
{
void(*_pFunc)(void  *);//函数
void *_pPara; //参数
JobItem(void(*pFunc)(void  *) = NULL, void *pPara = NULL) : _pFunc(pFunc), _pPara(pPara) { };
};
//线程池中的线程结构
struct ThreadItem
{
HANDLE _Handle; //线程句柄
ThreadPool *_pThis;  //线程池的指针
DWORD _dwLastBeginTime; //最后一次运行开始时间
DWORD _dwCount; //运行次数
bool _fIsRunning;
ThreadItem(ThreadPool *pthis) : _pThis(pthis), _Handle(NULL), _dwLastBeginTime(0), _dwCount(0), _fIsRunning(false) { };
~ThreadItem()
{
if (_Handle)
{
CloseHandle(_Handle);
_Handle = NULL;
}
}
};
std::queue<JobItem *> _JobQueue;  //工作队列
std::vector<ThreadItem *>  _ThreadVector; //线程数据
CRITICAL_SECTION _csThreadVector, _csWorkQueue; //工作队列临界, 线程数据临界
HANDLE _EventEnd, _EventComplete, _SemaphoreCall, _SemaphoreDel;//结束通知, 完成事件, 工作信号， 删除线程信号
long _lThreadNum, _lRunningNum; //线程数, 运行的线程数
};

ThreadPool Code
使用：

ThreadPool tp(10);
tp.Call(函数名[，函数参数]);