操作系統實驗29 同步與互斥

1、并發線程同步與互斥

源程序：

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <string.h>
int num=30,count=10;
pthread_mutex_t mylock=PTHREAD_MUTEX_INITIALIZER; 
void *sub1(void *arg) {int i = 0,tmp;for (; i <count; i++){pthread_mutex_lock(&mylock);    			tmp=num-1;usleep(13);num=tmp;								pthread_mutex_unlock(&mylock);	        		printf("線程1 num減1后值為: %d\n",num);}return ((void *)0);
}
void *sub2(void *arg){int i=0,tmp;for(;i<count;i++){pthread_mutex_lock(&mylock);tmp=num-1;usleep(31);num=tmp;pthread_mutex_unlock(&mylock);printf("線程2 num減1后值為: %d\n",num);}return ((void *)0);
}
int main(int argc, char** argv) {pthread_t tid1,tid2;int err,i=0,tmp;void *tret;err=pthread_create(&tid1,NULL,sub1,NULL);if(err!=0){printf("pthread_create error:%s\n",strerror(err));exit(-1);}
err=pthread_create(&tid2,NULL,sub2,NULL);if(err!=0){printf("pthread_create error:%s\n",strerror(err));exit(-1);}for(;i<count;i++){pthread_mutex_lock(&mylock);     			tmp=num-1;usleep(5);	num=tmp;		pthread_mutex_unlock(&mylock); printf("main num減1后值為: %d\n",num);}printf("兩個線程運行結束\n");err=pthread_join(tid1,&tret);
if(err!=0){printf("can not join with thread1:%s\n",strerror(err));exit(-1);}printf("thread 1 exit code %d\n",(int)tret);err=pthread_join(tid2,&tret);if(err!=0){printf("can not join with thread1:%s\n",strerror(err));exit(-1);}printf("thread 2 exit code %d\n",(int)tret);return 0;
}

編譯鏈接命令：gcc threadmutex.c -o threadmutex -lpthread

運行命令：./threadmutex

交互與結果：

2、生產者-消費者同步與互斥試驗

源程序：

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <pthread.h>
#include <unistd.h>
#include <signal.h>
#include <semaphore.h>
#define Maxbuf 10		//緩沖單元數目
#define TimesOfOp 10		//生產者、消費者循環讀寫緩沖區的次數
#define true 1
#define false 0
#define historynum 100	//生產者、消費者讀寫歷史記錄數目
struct Circlebuf	//循環緩沖隊列結構
{int read; 			//讀指針int write; 		//寫指針int buf[Maxbuf]; 	//緩沖區
} circlebuf;
sem_t mutex;			//互斥信號量
sem_t empty; 			//空白緩沖區同步信號量
sem_t full; 			//滿緩沖區同步信號量
char writehistory[historynum][30];//寫歷史
char readhistory[historynum][30];//讀歷史
int writehistorycount=0;		//寫歷史計數器
int readhistorycount=0; 		//讀歷史計數器
char history[historynum][30];	//緩沖區操作歷史
int historycount=0;		//緩沖區操作歷史計數器
void writeCirclebuf(struct Circlebuf *circlebuf,int *value) //向緩沖區中寫一個值
{circlebuf->buf[circlebuf->write]=(*value);sleep(1);							circlebuf->write=(circlebuf->write+1)%Maxbuf; 
}
int readCirclebuf(struct Circlebuf *circlebuf)
{int value=0;value=circlebuf->buf[circlebuf->read];		sleep(1);								circlebuf->buf[circlebuf->read]=0; 			circlebuf->read=(circlebuf->read+1)%Maxbuf; 	return value;
}
void sigend(int sig)
{exit(0);
}
void * productThread(void *i)
{int *n=(int *)i;int t=TimesOfOp;int writeptr;while(t--){	sem_wait(&empty);sem_wait(&mutex);writeCirclebuf(&circlebuf,n);if(circlebuf.write>0) writeptr=circlebuf.write-1;else writeptr= Maxbuf-1;sprintf(writehistory[writehistorycount++],"生產者%d:緩沖區%d=%d", *n,writeptr,*n);sprintf(history[historycount++],"生產者%d:緩沖區%d=%d\n", *n,writeptr, *n);sem_post(&mutex);sem_post(&full);sleep(1);}
}
void * consumerThread(void *i)
{int *n=(int *)i;int t=TimesOfOp;						int value=0;							int readptr;							while(t--){sem_wait(&full);						sem_wait(&mutex);value=readCirclebuf(&circlebuf);			if(circlebuf.read>0) readptr=circlebuf.read-1;	else readptr= Maxbuf-1;sprintf(readhistory[readhistorycount++], "消費者%d:緩沖區%d=%d\n", *n,readptr,value);sprintf(history[historycount++],"消費者%d:緩沖區%d=%d\n", *n,readptr,value);sem_post(&mutex);						sem_post(&empty);						sleep(1);							}
}
int main()
{int i,max;int ConsNum=0,ProdNum=0,ret;sem_init(&mutex,0,1);sem_init(&empty,0,Maxbuf);sem_init(&full,0,0);	signal(SIGINT, sigend);signal(SIGTERM, sigend);circlebuf.read=circlebuf.write=0;for(i=0;i<Maxbuf;i++)circlebuf.buf[i]=0;printf("請輸入生產者線程的數目 :");scanf("%d",&ProdNum);int *pro=(int*)malloc(ProdNum*sizeof(int));pthread_t *proid=(pthread_t*)malloc(ProdNum*sizeof(pthread_t));printf("請輸入消費者線程的數目 :");scanf("%d",&ConsNum);int *con=(int*)malloc(ConsNum*sizeof(int));pthread_t *conid=(pthread_t*)malloc(ConsNum*sizeof(pthread_t));for(i=1;i<=ConsNum;i++){con[i-1]=i;ret=pthread_create(&conid[i],NULL,consumerThread,(void *)&con[i-1]);if(ret!=0){printf("Create thread error");exit(1);}}for(i=1;i<=ProdNum;i++){pro[i-1]=i;ret=pthread_create(&proid[i],NULL,productThread,(void *)&pro[i-1]);if(ret!=0){printf("Create thread error");exit(1);}}sleep((ConsNum+ ProdNum)*10);if (writehistorycount>readhistorycount) max=writehistorycount;else max=readhistorycount;for(i=0;i<max;i++)if ((i<writehistorycount) && (i<readhistorycount))printf("%s | %s\n",writehistory[i],readhistory[i]);else if (i<writehistorycount)printf("%s | %s\n",writehistory[i]," ");else 	printf("%s | %s\n"," ",readhistory[i]);printf("*************緩沖池的操作歷史為：******************\n");for(i=0;i<historycount;i++)  printf("%s",history[i]);sem_destroy(&mutex);	sem_destroy(&empty);sem_destroy(&full);
}

編譯鏈接命令：gcc pc1.c -o pc1 -lpthread

運行命令：./pc1

交互與結果：

3、生產者-消費者未加同步與互斥機制的運行試驗

源程序：

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <pthread.h>
#include <unistd.h>
#include <signal.h>
#define Maxbuf 10       //緩沖單元數目
#define TimesOfOp 10    //生產者、消費者循環讀寫緩沖區的次數
#define true 1
#define false 0
#define historynum 100  //生產者、消費者讀寫歷史記錄數目
struct Circlebuf    //循環緩沖隊列結構
{int read;            //讀指針int write;       //寫指針int buf[Maxbuf];    //緩沖區
} circlebuf;char writehistory[historynum][30];//寫歷史
char readhistory[historynum][30];//讀歷史
int writehistorycount=0;        //寫歷史計數器
int readhistorycount=0;         //讀歷史計數器
char history[historynum][30];    //緩沖區操作歷史
int historycount=0;        //緩沖區操作歷史計數器void writeCirclebuf(struct Circlebuf *circlebuf,int *value) //向緩沖區中寫一個值
{circlebuf->buf[circlebuf->write]=(*value);sleep(1);                           circlebuf->write=(circlebuf->write+1)%Maxbuf; 
}
int readCirclebuf(struct Circlebuf *circlebuf)
{int value=0;value=circlebuf->buf[circlebuf->read];        sleep(1);                                circlebuf->buf[circlebuf->read]=0;            circlebuf->read=(circlebuf->read+1)%Maxbuf;     return value;
}void sigend(int sig)
{exit(0);
}void * productThread(void *i)
{int *n=(int *)i;int t=TimesOfOp;int writeptr;while(t--){   writeCirclebuf(&circlebuf,n);if(circlebuf.write>0) writeptr=circlebuf.write-1;else writeptr= Maxbuf-1;sprintf(writehistory[writehistorycount++],"生產者%d:緩沖區%d=%d", *n,writeptr,*n);sprintf(history[historycount++],"生產者%d:緩沖區%d=%d\n", *n,writeptr, *n);sleep(1);}
}void * consumerThread(void *i)
{int *n=(int *)i;int t=TimesOfOp;                        int value=0;                            int readptr;                            while(t--){value=readCirclebuf(&circlebuf);            if(circlebuf.read>0) readptr=circlebuf.read-1;    else readptr= Maxbuf-1;sprintf(readhistory[readhistorycount++], "消費者%d:緩沖區%d=%d\n", *n,readptr,value);sprintf(history[historycount++],"消費者%d:緩沖區%d=%d\n", *n,readptr,value);sleep(1);}
}int main()
{int i,max;int ConsNum=0,ProdNum=0,ret;circlebuf.read=circlebuf.write=0;for(i=0;i<Maxbuf;i++)circlebuf.buf[i]=0;printf("請輸入生產者線程的數目 :");scanf("%d",&ProdNum);int *pro=(int*)malloc(ProdNum*sizeof(int));pthread_t *proid=(pthread_t*)malloc(ProdNum*sizeof(pthread_t));printf("請輸入消費者線程的數目 :");scanf("%d",&ConsNum);int *con=(int*)malloc(ConsNum*sizeof(int));pthread_t *conid=(pthread_t*)malloc(ConsNum*sizeof(pthread_t));for(i=1;i<=ConsNum;i++){con[i-1]=i;ret=pthread_create(&conid[i],NULL,consumerThread,(void *)&con[i-1]);if(ret!=0){printf("Create thread error");exit(1);}}for(i=1;i<=ProdNum;i++){pro[i-1]=i;ret=pthread_create(&proid[i],NULL,productThread,(void *)&pro[i-1]);if(ret!=0){printf("Create thread error");exit(1);}}sleep((ConsNum+ ProdNum)*10);if (writehistorycount>readhistorycount) max=writehistorycount;else max=readhistorycount;for(i=0;i<max;i++)if ((i<writehistorycount) && (i<readhistorycount))printf("%s | %s\n",writehistory[i],readhistory[i]);else if (i<writehistorycount)printf("%s | %s\n",writehistory[i]," ");else    printf("%s | %s\n"," ",readhistory[i]);printf("*************緩沖池的操作歷史為：******************\n");for(i=0;i<historycount;i++)  printf("%s",history[i]);
}

編譯鏈接命令：gcc pc2.c -o pc2?-lpthread

運行命令：./pc2

交互與結果：