Linux学习之线程封装四：基于接口的封装

业务逻辑提供者类"CLThreadFunctionProvider"

头文件：

#ifndef CLTHREADFUNCTIONPROVIDER_H
#define CLTHREADFUNCTIONPROVIDER_H

#include "CLStatus.h"

class CLThreadFunctionProvider
{
public:
    CLThreadFunctionProvider();
    virtual ~CLThreadFunctionProvider();

public:
    virtual CLStatus RunThreadFunction(void *pContext) = 0;

private:
    CLThreadFunctionProvider(const CLThreadFunctionProvider&);
    CLThreadFunctionProvider& operator=(const CLThreadFunctionProvider&);
};

#endif

抽象类，用户自己提供业务逻辑，私有化复制构造函数和“=”操作符，保证对象访问的唯一性。
实现：

#include "CLThreadFunctionProvider.h"

CLThreadFunctionProvider::CLThreadFunctionProvider()
{
}

CLThreadFunctionProvider::~CLThreadFunctionProvider()
{
}

具体由用户实现。
线程类"CLThread"

头文件：

#ifndef CLTHREAD_H
#define CLTHREAD_H

#include <pthread.h>
#include "CLStatus.h"

class CLThreadFunctionProvider;

class CLThread
{
public:
    CLThread(CLThreadFunctionProvider *pThreadFunctionProvider);
    virtual ~CLThread();

    CLStatus Run(void *pContext = 0);
    CLStatus WaitForDeath();

private:
    static void* StartFunctionOfThread(void *pContext);

protected:
    void *m_pContext;
    pthread_t m_ThreadID;

    CLThreadFunctionProvider *m_pThreadFunctionProvider;
};

#endif

CLThreadFunctionProvider再投文件中只需声明，无需include "CLThreadFunctionProvider.h"，因为没有用到具体的成员。
实现：

#include "CLThread.h"
#include "CLLog.h"
#include "CLThreadFunctionProvider.h"

CLThread::CLThread(CLThreadFunctionProvider *pThreadFunctionProvider)
{
    m_pThreadFunctionProvider = pThreadFunctionProvider;

    m_pContext = 0;
}

CLThread::~CLThread()
{
}

CLStatus CLThread::Run(void *pContext)
{    
    m_pContext = pContext;

    int r = pthread_create(&m_ThreadID, 0, StartFunctionOfThread, this);
    if(r != 0)
    {
        CLLog::WriteLogMsg("In CLThread::Run(), pthread_create error", r);
        return CLStatus(-1, 0);
    }

    return CLStatus(0, 0);
}

CLStatus CLThread::WaitForDeath()
{
    int r = pthread_join(m_ThreadID, 0);
    if(r != 0)
    {
        CLLog::WriteLogMsg("In CLThread::WaitForDeath(), pthread_join error", r);
        return CLStatus(-1, 0);
    }

    return CLStatus(0, 0);
}

void* CLThread::StartFunctionOfThread(void *pThis)
{
    CLThread *pThreadThis = (CLThread *)pThis;

    CLStatus s = pThreadThis->m_pThreadFunctionProvider->RunThreadFunction(pThreadThis->m_pContext);

    return (void *)s.m_clReturnCode;
}

调用：

#include <iostream>
#include <unistd.h>
#include "CLThread.h"
#include "CLThreadFunctionProvider.h"

using namespace std;

class CLParaPrinter : public CLThreadFunctionProvider
{
public:
    CLParaPrinter()
    {
    }

    virtual ~CLParaPrinter()
    {
    }

    virtual CLStatus RunThreadFunction(void *pContext)
    {
    int i = (int)pContext;
    cout << i << endl;
    }
};

int main()
{
    CLParaPrinter *printer = new CLParaPrinter();
    CLThread *pThread = new CLThread(printer);

    pThread->Run((void *)2);
    pThread->WaitForDeath();

    delete pThread;
    delete printer;

    return 0;
}