zthread学习 实例四 让步、休眠、优先级

1、让步

Thread::yield()可以介入CPU的调度，使CPU强制放弃执行当前线程。

2、休眠

Thread:sleep()可以使线程停止执行一段时间。

Thread:sleep()可发抛出一个Interrupted_Exception，该异常必须在run()函数中捕获，因为异常是不会跨线程传播的，只能在线程内部处理。

3、优先级

Thread::setPriority()、Thread::getPriority(),可以人为的改变到线程执行的优先级，确保紧急的任务先执行。

实例如下：

[cpp] view
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#include "stdafx.h"

#include <iostream>

#include <fstream>

#include "zthread/Runnable.h"

#include "zthread/Thread.h"

#include "zthread/PoolExecutor.h"

using namespace ZThread;

using namespace std;

const double pi = 3.141592653589793;

const double e = 2.718281828459;

class SimplePriorities : public Runnable

{

public:

SimplePriorities(int idn = 0): id(idn), nCountDown(5){}

~SimplePriorities(){}

friend ostream& operator << (ostream& os, const SimplePriorities& sp)

{

return os << "#" << sp.id << " priority : " <<Thread().getPriority() << "count : " << sp.nCountDown <<endl;

}

void run()

{

while (true)

{

for (int i = 0; i < 10000; i++)

{

d = d + (pi + e) /double(i);

}

cout << *this <<endl;

if (--nCountDown == 0) return;

}

}

private:

int nCountDown;

int id;

volatile double d;

};

int _tmain(int argc, _TCHAR* argv[])

{

try

{

Thread high(new SimplePriorities);

high.setPriority(Priority::High);

for (int i = 1; i < 5; i++)

{

Thread low(new SimplePriorities(i));

low.setPriority(Priority::Low);

}

cin.get();

}

catch (Synchronization_Exception& e)

{

cerr << e.what() <<endl;

}

cin.get();

return 0;

}