双缓冲的誉抄的过程

来源：互联网发布：轻淘客插件 mac 编辑：程序博客网时间：2024/05/17 09:06

程序一利用双缓冲、三线程的串行执行实现从输入文件到屏幕的拷贝输出：

代码如下：

#include<windows.h>

#include<iostream>

using namespacestd;

FILE *infile;

char buf1,buf2;

void get(){buf1=fgetc(infile);}

void copy(){buf2=buf1;}

void put( ){putchar(buf2);}

int main()

{

infile=fopen("in.txt","r");

for(;buf1!=EOF;)

{

get();

copy();

put();

}

fclose(infile);

return 0;

}

程序二实现线程的随机并发执行：

代码如下：

#include <cstdio>

#include "conio.h"

#include "windows.h"

#include <iostream>

using namespace std;

typedef struct _THREADDATA

{

FILE*infile;

char*buf1;

char*buf2;

}*LPTHREADDATA, THREADDATA;

DWORD WINAPI get(LPVOID lParam)

{

LPTHREADDATA pData = (LPTHREADDATA)lParam;

for (;*pData->buf1!=EOF;)

{

*pData->buf1=fgetc(pData->infile);

Sleep(1);

}

return 0;

}

DWORD WINAPI copy(LPVOID lParam)

{

LPTHREADDATA pData = (LPTHREADDATA)lParam;

for (;*pData->buf1!=EOF;)

*pData->buf2=*pData->buf1;

return0;

}

DWORD WINAPI put(LPVOID lParam)

{

LPTHREADDATA pData = (LPTHREADDATA)lParam;

for (;*pData->buf1!=EOF;)

{

cout<<*pData->buf2<<endl;

Sleep(1);

}

return 0;

}

int main()

{

FILE*infile=fopen("in.txt","r");

charbuf1,buf2;

LPTHREADDATA pData = new THREADDATA;

pData->infile=infile;

pData->buf1=&buf1;

pData->buf2=&buf2;;

DWORD ThreadId1,ThreadId2,ThreadId3;

::CreateThread(NULL,0, get, (LPVOID)pData, 0, &ThreadId1);

::CreateThread(NULL,0, copy, (LPVOID)pData, 0, &ThreadId2);

::CreateThread(NULL,0, put, (LPVOID)pData, 0, &ThreadId3);

getch();

fclose(infile);

return0;

}

程序三控制进程实现正确的并发誊抄：

代码如下：

#include <cstdio>

#include "conio.h"

#include "windows.h"

#include <iostream>

using namespace std;

HANDLE Mutex;

HANDLE buf1_e;

HANDLE buf1_f;

HANDLE buf2_e;

HANDLE buf2_f;

typedef struct _THREADDATA

{

FILE*infile;

char*buf1;

char*buf2;

}*LPTHREADDATA, THREADDATA;

DWORD WINAPI get(LPVOID lParam)

{

LPTHREADDATApData = (LPTHREADDATA)lParam;

for (;*pData->buf1!=EOF;)

{

WaitForSingleObject(buf1_e,INFINITE);

*pData->buf1=fgetc(pData->infile);

ReleaseSemaphore(buf1_f,1,NULL);

}

return 0;

}

DWORD WINAPI copy(LPVOID lParam)

{

LPTHREADDATApData = (LPTHREADDATA)lParam;

for (;*pData->buf1!=EOF;)

{

WaitForSingleObject(buf1_f,INFINITE);

WaitForSingleObject(buf2_e,INFINITE);

*pData->buf2=*pData->buf1;

ReleaseSemaphore(buf1_e,1,NULL);

ReleaseSemaphore(buf2_f,1,NULL);

}

return 0;

}

DWORD WINAPI put(LPVOID lParam)

{

LPTHREADDATApData = (LPTHREADDATA)lParam;

for (;*pData->buf1!=EOF;)

{

WaitForSingleObject(buf2_f,INFINITE);

cout<<*pData->buf2;

ReleaseSemaphore(buf2_e,1,NULL);

}

return 0;

}

int main()

{

// Mutex=CreateMutex(NULL,FALSE,NULL);

buf1_e=CreateSemaphore(NULL,1,1,NULL);

buf1_f=CreateSemaphore(NULL,0,1,NULL);

buf2_e=CreateSemaphore(NULL,1,1,NULL);

buf2_f=CreateSemaphore(NULL,0,1,NULL);

FILE*infile=fopen("in.txt","r");

charbuf1,buf2;

LPTHREADDATA pData = new THREADDATA;

pData->infile=infile;

pData->buf1=&buf1;

pData->buf2=&buf2;

DWORDThreadId1,ThreadId2,ThreadId3;

::CreateThread(NULL,0, copy, (LPVOID)pData, 0, &ThreadId2);

::CreateThread(NULL,0, put, (LPVOID)pData, 0, &ThreadId3);

::CreateThread(NULL,0, get, (LPVOID)pData, 0, &ThreadId1);

getch();

fclose(infile);

return 0;

}

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