1、并发线程同步与互斥
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("线程1 num减1后值为: %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("线程2 num减1后值为: %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减1后值为: %d\n",num);
}
printf("两个线程运行结束\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;
}
编译链接命令：gcc threadmutex.c -o threadmutex -lpthread
运行命令：./threadmutex
交互与结果：
2、生产者-消费者同步与互斥试验
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 //缓冲单元数目
#define TimesOfOp 10 //生产者、消费者循环读写缓冲区的次数
#define true 1
#define false 0
#define historynum 100 //生产者、消费者读写历史记录数目
struct Circlebuf //循环缓冲队列结构
{
int read; //读指针
int write; //写指针
int buf[Maxbuf]; //缓冲区
} circlebuf;
sem_t mutex; //互斥信号量
sem_t empty; //空白缓冲区同步信号量
sem_t full; //满缓冲区同步信号量
char writehistory[historynum][30];//写历史
char readhistory[historynum][30];//读历史
int writehistorycount=0; //写历史计数器
int readhistorycount=0; //读历史计数器
char history[historynum][30]; //缓冲区操作历史
int historycount=0; //缓冲区操作历史计数器
void writeCirclebuf(struct Circlebuf *circlebuf,int *value) //向缓冲区中写一个值
{
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++],"生产者%d:缓冲区%d=%d", *n,writeptr,*n);
sprintf(history[historycount++],"生产者%d:缓冲区%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++], "消费者%d:缓冲区%d=%d\n", *n,readptr,value);
sprintf(history[historycount++],"消费者%d:缓冲区%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("请输入生产者线程的数目 :");
scanf("%d",&ProdNum);
int *pro=(int*)malloc(ProdNum*sizeof(int));
pthread_t *proid=(pthread_t*)malloc(ProdNum*sizeof(pthread_t));
printf("请输入消费者线程的数目 :");
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("*************缓冲池的操作历史为：******************\n");
for(i=0;i<historycount;i++) printf("%s",history[i]);
sem_destroy(&mutex);
sem_destroy(&empty);
sem_destroy(&full);
}
编译链接命令：gcc pc1.c -o pc1 -lpthread
运行命令：./pc1
交互与结果：
3、生产者-消费者未加同步与互斥机制的运行试验
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 //缓冲单元数目
#define TimesOfOp 10 //生产者、消费者循环读写缓冲区的次数
#define true 1
#define false 0
#define historynum 100 //生产者、消费者读写历史记录数目
struct Circlebuf //循环缓冲队列结构
{
int read; //读指针
int write; //写指针
int buf[Maxbuf]; //缓冲区
} circlebuf;
char writehistory[historynum][30];//写历史
char readhistory[historynum][30];//读历史
int writehistorycount=0; //写历史计数器
int readhistorycount=0; //读历史计数器
char history[historynum][30]; //缓冲区操作历史
int historycount=0; //缓冲区操作历史计数器
void writeCirclebuf(struct Circlebuf *circlebuf,int *value) //向缓冲区中写一个值
{
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++],"生产者%d:缓冲区%d=%d", *n,writeptr,*n);
sprintf(history[historycount++],"生产者%d:缓冲区%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++], "消费者%d:缓冲区%d=%d\n", *n,readptr,value);
sprintf(history[historycount++],"消费者%d:缓冲区%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("请输入生产者线程的数目 :");
scanf("%d",&ProdNum);
int *pro=(int*)malloc(ProdNum*sizeof(int));
pthread_t *proid=(pthread_t*)malloc(ProdNum*sizeof(pthread_t));
printf("请输入消费者线程的数目 :");
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("*************缓冲池的操作历史为：******************\n");
for(i=0;i<historycount;i++) printf("%s",history[i]);
}
编译链接命令：gcc pc2.c -o pc2 -lpthread
运行命令：./pc2
交互与结果：