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我正在学习关键部分(为了多线程的目的),并且我在网上找到了一个使用它的类。我不明白为什么我的代码无法正常工作 - 我应该在控制台显示屏上获得“成功”,但我不知道。嵌套锁(关键部分)不工作
我锁定不正确吗?我确信我正在准确地进入和退出这些部分 - 但我不知道为什么第三个线程(mul
)似乎不起作用。
这里是主代码(在VS 2012做这个):
#include "stdafx.h"
#include <windows.h>
#include <process.h>
#include <iostream>
#include <assert.h>
#include <queue>
#include "Lock.h"
//File: CriticalSectionExample.cpp
#define MAX_THREADS 2
using namespace std;
static unsigned int counter = 100;
static bool alive = true;
static examples::Lock lock_1;
static examples::Lock lock_2;
queue<int> test_q;
queue<int> later_q;
static unsigned __stdcall sub(void *args)
{
while(alive)
{
cout << "tq";
lock_1.acquire();
test_q.push(1);
lock_1.release();
::Sleep(500);
}
return 0;
}
static unsigned __stdcall add(void *args)
{
while(alive)
{
if (!test_q.empty())
{
int first = test_q.front();
//cout << first << endl;
lock_1.acquire();
test_q.pop();
lock_1.release();
lock_2.acquire();
cout << "lq" << first << endl;
later_q.push(first);
lock_2.release();
}
::Sleep(500);
}
return 0;
}
static unsigned __stdcall mul(void *args)
{
while(alive)
{
if (!later_q.empty())
{
cout << "success" << endl;
lock_2.acquire();
test_q.pop();
lock_2.release();
}
::Sleep(500);
}
return 0;
}
int main()
{
// create threads
unsigned tadd;
HANDLE hadd = (HANDLE) ::_beginthreadex(0, 0, &add, 0, CREATE_SUSPENDED, &tadd);
assert(hadd != 0);
unsigned tsub;
HANDLE hsub = (HANDLE) ::_beginthreadex(0, 0, &sub, 0, CREATE_SUSPENDED, &tsub);
assert(hsub != 0);
unsigned tmul;
HANDLE hmul = (HANDLE) ::_beginthreadex(0, 0, &mul, 0, CREATE_SUSPENDED, &tsub);
assert(hmul != 0);
// start threads
::ResumeThread(hadd);
::ResumeThread(hsub);
::Sleep(10000); // let threads run for 10 seconds
// stop & cleanup threads
alive = false;
::WaitForSingleObject(hsub, INFINITE);
::CloseHandle(hsub);
::WaitForSingleObject(hadd, INFINITE);
::CloseHandle(hadd);
return 0;
}
,这是包括关键节的头文件:
#ifndef _Lock_H_
#define _Lock_H_
#include <windows.h>
/**
*@description: A simple Lock implementation using windows critical section object
*/
namespace examples
{
class Lock
{
public:
Lock()
{
::InitializeCriticalSection(&m_cs);
}
~Lock()
{
::DeleteCriticalSection(&m_cs);
}
void acquire()
{
::EnterCriticalSection(&m_cs);
}
void release()
{
::LeaveCriticalSection(&m_cs);
}
private:
Lock(const Lock&);
Lock& operator=(const Lock&);
CRITICAL_SECTION m_cs;
};
}
#endif //_Lock_H_
谢谢你。但是在VS2012上,有一个与'AutoLock(Lock&l)'有关的错误 - 它一直告诉我它期望有一个')'。那有什么问题?它适用于VS2010,但不适用于2012. – sccs 2013-05-03 07:21:39
也许你试图在Lock声明之上声明类AutoLock。在这种情况下,编译器不知道Lock是什么,因此期望别的东西。如果这不是问题复制错误在这里,也许与编译日志首先发生此错误。 – Bogolt 2013-05-03 08:17:50
我做了愚蠢的事情(并且把'l'看作'1'),这就是问题所在。非常感谢你! – sccs 2013-05-03 08:26:21