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作業系統中關于信号量操作的代碼示例(Linux+windows)
原文：作業系統中關于信号量操作的代碼示例(Linux+windows)
有一個生産者程序，有兩個消費者程序。生産者産生1-100的100個數。兩個消費者從共享記憶體中取數。
// Thread.cpp : 定義控制台應用程式的入口點。
//-----------Windows下生産者、消費者執行個體程式---------------------
//--------------author:zhangwei----------------------------------
//--------------Date 12/10/2004---------------------------------
#include "stdafx.h"
//作為倉庫存放資料，最多可以放五個資料
int array[5];
//記錄生成資料的個數
int pointer;
//記錄取得的資料的位置
int pointerget;
//用來儲存資料和
int sum;
//臨界區對象
CRITICAL_SECTION csArray;
//句柄，儲存Full信号量
HANDLE hFull;
//句柄，儲存Empty信号量
HANDLE hEmpty;
//生産者函數
DWORD WINAPI Producer(LPVOID lpParam)
{
int i = 0;
pointer = 0;
while( i
{
WaitForSingleObject(hEmpty,INFINITE);
EnterCriticalSection( &csArray);
array[(pointer++)%5] = i + 1;
LeaveCriticalSection( &csArray);
ReleaseSemaphore(hFull,1,NULL);
i++;
}
return 0;
}
//消費者函數A
DWORD WINAPI ConsumerA(LPVOID lpParam)
{
while(1)
{
WaitForSingleObject(hFull,INFINITE);
EnterCriticalSection( &csArray);
sum += array[(pointerget ++ )%5];
printf("ConsumerA get %d \n",array[(pointerget -1)%5]);
if(pointerget == 100)
printf("The sum is %d",sum);
LeaveCriticalSection( &csArray);
ReleaseSemaphore(hEmpty,1,NULL);
}
return 0;
}
//消費者函數B
DWORD WINAPI ConsumerB(LPVOID lpParam)
{
while(1)
{
WaitForSingleObject(hFull,INFINITE);
EnterCriticalSection( &csArray);
sum += array[(pointerget ++ )%5];
printf("ConsumerB get %d \n",array[(pointerget -1 )%5]);
if(pointerget == 100)
printf("The sum is %d",sum);
LeaveCriticalSection( &csArray);
ReleaseSemaphore(hEmpty,1,NULL);
}
return 0;
}
//主函數
void main()
{
HANDLE hThreadProducer,hThreadConsumerA,hThreadComsumerB;
sum = 0;
pointerget = 0;
InitializeCriticalSection( &csArray);
hFull = CreateSemaphore(NULL,0,5,NULL);
hEmpty = CreateSemaphore(NULL,5,5,NULL);
hThreadProducer = CreateThread(NULL,0,
Producer,NULL,0,NULL);
hThreadConsumerA = CreateThread(NULL,0,
ConsumerA,NULL,0,NULL);
hThreadComsumerB = CreateThread(NULL,0,
ConsumerB,NULL,0,NULL);
_getch();
}
#include
#include
#include
#include
#include
#include
#include
#include
#define MAXSEM 5
//聲明三個信号燈ID
int fullid;
int emptyid;
int mutxid;
int main()
{
struct sembuf P,V;;
union semun arg;
//聲明共享記憶體
int *array;
int *sum;
int *set;
int *get;
//映射共享記憶體
array = (int *)mmap(NULL , sizeof( int )*5,PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANONYMOUS,-1,0);
sum = (int *)mmap(NULL , sizeof( int ),PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANONYMOUS,-1,0);
get = (int *)mmap(NULL , sizeof( int ),PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANONYMOUS,-1,0);
set = (int *)mmap(NULL , sizeof( int ),PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANONYMOUS,-1,0);
*sum = 0;
*get = 0;
*set = 0;
//生成信号燈
fullid= semget(IPC_PRIVATE,1,IPC_CREAT|00666);
emptyid=semget(IPC_PRIVATE,1,IPC_CREAT|00666);
mutxid=semget(IPC_PRIVATE,1,IPC_CREAT|00666);
//為信号燈指派
arg.val = 0;
if(semctl(fullid , 0 , SETVAL , arg) == -1) perror("semctl setval error");
arg.val = MAXSEM;
if(semctl(emptyid , 0 ,SETVAL , arg) == -1) perror("semctl setval error");
arg.val = 1;
if(semctl(mutxid , 0 ,SETVAL , arg) == -1) perror("setctl setval error");
//初始化P,V操作
V.sem_num=0;
V.sem_op =1;
V.sem_flg=SEM_UNDO;
P.sem_num=0;
P.sem_op =-1;
P.sem_flg=SEM_UNDO;
//生産者程序
if(fork() == 0 ) {
int i = 0;
while( i
{
semop(emptyid , &P ,1 );
semop(mutxid , &P , 1);
array[*(set)%MAXSEM] = i + 1;
printf("Producer %d\n", array[(*set)%MAXSEM]);
(*set)++;
semop(mutxid , &V , 1);
semop(fullid , &V , 1);
i++;
}
sleep(10);
printf("Producer is over");
exit(0);
}else {
//ConsumerA 程序
if(fork()==0) {
while(1){
semop(fullid , &P , 1);
semop(mutxid , &P , 1);
if(*get == 100)
break;
*sum += array[(*get)%MAXSEM];
printf("The ComsumerA Get Number %d\n", array[(*get)%MAXSEM] );
(*get)++;
if( *get ==100)
printf("The sum is %d \n ", *sum);
semop(mutxid , &V , 1);
semop(emptyid , &V ,1 );
sleep(1);
}
printf("ConsumerA is over");
exit(0);
}else {
//Consumer B程序
if(fork()==0) {
while(1){
semop(fullid , &P , 1);
semop(mutxid , &P , 1);
if(*get == 100)
break;
*sum += array[(*get)%MAXSEM];
printf("The ComsumerB Get Number %d\n", array[(*get)%MAXSEM] );
(*get)++;
if( *get ==100)
printf("The sum is %d \n ", *sum);
semop(mutxid , &V , 1);
semop(emptyid , &V ,1 );
sleep(1);
}
printf("ConsumerB is over");
exit(0);
}
}
}
// sleep(20);
return 0;
}
我的第一篇文章，多多指教。如需練習mail:[email protected]