1018 std::thread 使用(建立class 避免無法釋放資源)

修改成功的範例:

功能

1.建立為class 可以自己釋放資源

2.釋放的thread 記得用join 

3.利用 getInstance() ，使程式不用特定init

   (不過在此還是有特定建立無用的initCMDData() 來提早初始化

4.確認再PC上可以正常結束 不會有異常

.H

class PomeloThreadClass 

{

public:

//CREATE_FUNC(PomeloThreadClass);

PomeloThreadClass();

~PomeloThreadClass();

static PomeloThreadClass* getInstance();

//指令相關函數.

void saveCMD(int cmdID, const char* pData); //紀錄指令資料.

void nextCMDID(); //指向下一個空間.

bool bNewCmdID(); //判斷是否有新指令.

void initCMDData(); //初始化指令空間

//執行緒主函數

void initThread();

void notify();

void mainFunction();

private:

std::thread pomelo_thread;

std::mutex pomelo_mtx;

std::condition_variable pomelo_threadcv;

bool ThreadEndFlag ;

pomeloCmd_t pomeloCMD[MAX_POMELO_CMDID];

int pomelpCmdIdx_Save ;

int pomelpCmdIdx_Now ;

};

.CPP //非完整程式碼 部分函數沒有貼上

static PomeloThreadClass* m_Thread = nullptr;

PomeloThreadClass::PomeloThreadClass():

ThreadEndFlag(false),

pomelpCmdIdx_Save(0),

pomelpCmdIdx_Now(0)

{

initCMDData();

}

void PomeloThreadClass::initCMDData()

{

for (int i = 0; i < MAX_POMELO_CMDID; i++)

{

memset(pomeloCMD, 0, sizeof(pomeloCmd_t));

pomeloCMD[i].cmdID = POCMDID_NULL_CMDID;

}

pomelpCmdIdx_Save = 0;

pomelpCmdIdx_Now = 0;

}

PomeloThreadClass::~PomeloThreadClass()

{

if (pomelo_thread.joinable())

pomelo_thread.join();

if (!m_Thread)

{

free(m_Thread);

m_Thread = nullptr;

}

}

PomeloThreadClass* PomeloThreadClass::getInstance()

{

if (!m_Thread)

{

m_Thread = new PomeloThreadClass;

m_Thread->initThread();

}

return m_Thread;

}

//建立接收的網路的thread

void PomeloThreadClass::initThread()

{

pomelo_thread = std::thread(&PomeloThreadClass::mainFunction, this);

pomelo_thread.detach(); //產生新的Thread 不用等待結束

}

//通知thread

void PomeloThreadClass::notify()

{

pomelo_threadcv.notify_one(); //取得回傳數值

}

void PomeloThreadClass::mainFunction()

{

std::unique_lock<std::mutex> threadMtx(pomelo_mtx);

int restule = 0;

try

{

while (!ThreadEndFlag)

{

pomelo_threadcv.wait(threadMtx); //等待訊號

while (bNewCmdID())

{

switch (pomeloCMD[pomelpCmdIdx_Now].cmdID)

{

case POCMDID_Login:

log("LogOK");

ChangLayer_MainSlot();

break;

default:

break;

}

nextCMDID();

}

}

}

catch (std::exception const & ex) 

{

log("it's trouble when thread close");

// perhaps log the message, ex.what()

}

}

原始參考範例
https://stackoverflow.com/questions/38538438/how-to-terminate-a-stdthread

class YourClass {
public:
    ~YourClass() {
        if (_thread != nullptr) {
            _thread->join();
            delete _thread;
        }
    }
    void mainProcees() {
        _thread = new thread(&YourClass::downloadImg,this);
    }
private:
    thread *_thread = nullptr;
};

UPDATE

Just as @milleniumbug pointed out, you don't need dynamic allocation for the thread object, since it is movable. So the other solution is as follows.

class YourClass {
public:
    ~YourClass() {
        if (_thread.joinable())
            _thread.join();
    }
    void mainProcess() {
        _thread = std::thread(&YourClass::downloadImg, this);
    }
private:
    std::thread _thread;
};