p11-21.c

SUN Solaris8平台下进程间通信

#include "outshm.h"

int main(void) /* 服务程序 */
{
    struct exchange *shm, *s;
    int producer,consumer,i;
	int shmid;
    char readbuf[BUFSIZ];
	key_t key1=123,key2=456;

    /* 创建信号量consumer和producer */
    consumer = semget( key1, 1, IPC_EXCL|IPC_CREAT | 0660 );
    producer = semget( key2, 1, IPC_EXCL|IPC_CREAT | 0660 );
    if ((consumer == -1||producer == -1)&&(errno==EEXIST)){
        printf("Semaphore already exists,Server may already run.\n");
        exit(0);
    }
	
    /* 初始信号量consumer和producer */
    init_a_semaphore(consumer, 0, 0);  /* 禁止消费 */
    init_a_semaphore(producer, 0, 1);  /* 允许生产 */

    /* 获得并连接名为"shared"的共享存储段 */
    shm = (struct exchange *)shminit(ftok("shared",0),&shmid);

    /* 从标准输入读数据并写至共享存储段 */
    for ( i=0; ; i++ ) {
         /* 读入数据 */
        semaphore_P(producer);   /* 等待客户进程释放共享存储段 */
        printf("Enter some text:");
        fgets(readbuf,BUFSIZ,stdin);
         /* 填充共享存储缓冲 */
        shm->seq = i;
        sprintf(shm->buf, "%s",readbuf);
        semaphore_V(consumer);  /* 允许客户进程取数据 */
        if (strncmp(readbuf, "end", 3) == 0 )
            break;
	}
    semaphore_P(producer);   /* 等待客户读毕共享存储段中的数据 */
    /* 删除信号量 */
    rm_semaphore(producer);
	rm_semaphore(consumer);

    /* 分离并删除共享存储段 */
    shmdt(shm);
    shmctl(shmid, IPC_RMID, (struct shmid_ds *)NULL);
    exit(0);
}