int main()
{
char *shm;
int shmid;
int producer, consumer, i;
consumer=open_semaphore_set(ftok("consumer",0),1);
init_a_semaphore(consumer,0,1);
producer=open_semaphore_set(ftok("producer",0),1);
init_a_semaphore(producer,0,1);
// shm=(struct exchange *)shminit(ftok("shared",0));
if((shmid=shmget(ftok("shared",0),SHMSZ, 0666|IPC_CREAT))==-1)
{
printf("shmget failed.\n");
exit(1);
}
shm=shmat(shmid,(unsigned char *)0,0);
for(i=0; ; i++)
{
semaphore_V(consumer);
semaphore_P(producer);
printf("Data receiverd: %s\n",shm);
sleep(1);
if(strcmp(shm,"end")==0)
break;
}
semctl(producer,0,IPC_RMID,0);
semctl(consumer,0,IPC_RMID,0);
}
int main()
{
struct exchange
{
char buf[BUFSIZ+80];
int seq;
}shm;
int shmid;
unsigned char *retval;
int producer, consumer, i;
char readbuf[BUFSIZ];
//创建信号量consumer
consumer = open_semaphore_set(ftok("consumer", 0), 1);
//初始化信号量consumer的值为1
init_a_semaphore(consumer, 0, 1);
//创建信号量producer
producer = open_semaphore_set(ftok("producer", 0), 1);
//初始化信号量producer的值为1
init_a_semaphore(producer, 0, 1);
//创建共享存储区用于存放生产者产生的数据
shmid = shmget(ftok("share", 0),sizeof(struct exchange), 0666|IPC_CREAT);
retval = shmat(shmid, (unsigned char *)0, 0);
//生产者与消费者同步
for (i = 0; ; i++)
{
printf("enter some text:");
fgets(readbuf, BUFSIZ, stdin);
semaphore_P(consumer);
sprintf(retval, "messge %2d form producer %d is \" %s \" ", i, getpid(), readbuf);
semaphore_V(producer);
if (strncmp(readbuf, "end", 3) == 0)
break;
}
exit(0);
return 0;
}
int main(void) /* 服務程式 */
{
struct exchange *shm;
int producer_ok,consumer_ok,i;
int shmid;
char readbuf[BUFSIZ];
/* 建立訊號量consumer和producer */
consumer_ok = open_semaphore_set(key1, 1);
producer_ok= open_semaphore_set(key2, 1);
init_a_semaphore(consumer_ok, 0, 1); /* 禁止消費 */
init_a_semaphore(producer_ok, 0, 0); /* 容許生產 */
/* 獲得並連線名為"shared"的共享儲存段 */
shm = (struct exchange *)shminit(ftok("shared",0),&shmid);
/* 從標准輸入讀資料並寫至共享儲存段 */
for ( i=0; ; i++ ) {
/* 讀入資料 */
semaphore_P(consumer_ok); /* 等待客戶執行緒釋放共享儲存段 */
printf("Enter some text:");
fgets(readbuf,BUFSIZ,stdin);
/* 填充共享儲存緩沖 */
shm->seq = i;
sprintf(shm->buf, "%s",readbuf);
semaphore_V(producer_ok); /* 容許客戶執行緒取資料 */
if (strncmp(readbuf, "end", 3) == 0 )
break;
}
semaphore_P(consumer_ok); /* 等待客戶執行緒消費完畢 */
/* 移除訊號量 */
rm_semaphore(producer_ok);
rm_semaphore(consumer_ok);
/* 分離並移除共享儲存段 */
shmdt(shm);
shmctl(shmid, IPC_RMID, (struct shmid_ds *)NULL);
exit(0);
}