Windows系统的多线程同步 Win32 Console Application

最新推荐文章于 2022-10-21 20:01:49 发布

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#application #多线程 #windows #winapi #thread #null

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本文展示了一个使用Windows API中的互斥锁（Mutex）来实现线程同步的例子。具体包括四个线程函数：两个写操作线程（write1和write2）及两个读操作线程（read1和read2）。通过互斥锁确保了写操作不会同时进行，并允许多个读操作并发执行。

操作系统实验课所写的代码：

#include <windows.h>

#include <iostream.h>

DWORD WINAPI write1(
  LPVOID lpParameter // thread data
);

DWORD WINAPI write2(
  LPVOID lpParameter // thread data
);

DWORD WINAPI read1(
  LPVOID lpParameter // thread data
);

DWORD WINAPI read2(
  LPVOID lpParameter // thread data
);

int flag = 0;

HANDLE hMutex=CreateMutex(NULL,FALSE,NULL);;
void main()
{
while(true)
{
   HANDLE ThWr1=CreateThread(NULL,0,write1,NULL,0,NULL);
   HANDLE ThWr2=CreateThread(NULL,0,write2,NULL,0,NULL);
   HANDLE ThRe1=CreateThread(NULL,0,read1,NULL,0,NULL);
   HANDLE ThRe2=CreateThread(NULL,0,read2,NULL,0,NULL);

CloseHandle(ThWr1);
CloseHandle(ThWr2);
CloseHandle(ThRe1);
CloseHandle(ThRe2);

if(hMutex)
{
if(ERROR_ALREADY_EXISTS==GetLastError())
{
cout<<"only instance can run!"<<endl;
return;
}
}

Sleep(5500); //交出cpu的使用权
}
}

DWORD WINAPI write1(
  LPVOID lpParameter // thread data
)
{
WaitForSingleObject(hMutex,INFINITE);
cout<<"write1 is writing"<<endl;
cout<<"Only write1 can running"<<endl;
Sleep(10); //交出cpu的使用权
cout<<"write1 dead"<<endl;
ReleaseMutex(hMutex);

return 0;
}

DWORD WINAPI write2(
  LPVOID lpParameter // thread data
)
{
WaitForSingleObject(hMutex,INFINITE);
cout<<"write2 is writing"<<endl;
cout<<"Only write2 can running"<<endl;
Sleep(10); //交出cpu的使用权
cout<<"wirte2 dead"<<endl;
ReleaseMutex(hMutex);

return 0;
}

DWORD WINAPI read1(
  LPVOID lpParameter // thread data
)
{
   Sleep(98);
if(flag >0)
cout<<"read1 is reading"<<endl;
// cout<<"yes"<<endl;
WaitForSingleObject(hMutex,INFINITE);
flag++;
cout<<"read1 is reading"<<endl;
cout<<"reading also can read,but writing can't"<<endl;
Sleep(10); //交出cpu的使用权
ReleaseMutex(hMutex);
   cout<<"read1 dead "<<endl;
flag--;
return 0;
}

DWORD WINAPI read2(
  LPVOID lpParameter // thread data
)
{
Sleep(98);
if(flag >0)
cout<<"read2 is reading"<<endl;
// cout<<"yes"<<endl;
WaitForSingleObject(hMutex,INFINITE);
flag++;
cout<<"read2 is reading"<<endl;
Sleep(10); //交出cpu的使用权

ReleaseMutex(hMutex);
cout<<"read2 dead"<<endl;
flag--;
return 0;
}