操作系统 实验五、进程互斥实验

#include"ipc.h" int main(int argc,char *argv[]){ int i; int rate; int w_mid; int count=MAXVAL; Msg_buf msg_arg; struct msqid_ds msg_inf; buff_key=101; buff_num=CHAIR; shm_flg=IPC_CREAT|0644; buff_ptr=(int*)set_shm(buff_key,buff_num,shm_flg); waiting_key=102; waiting_num=1; waiting_ptr=(int*)set_shm(waiting_key,waiting_num,shm_flg); // 注册消息队列 quest_flg=IPC_CREAT|0644; quest_key=201; quest_id=set_msq(quest_key,quest_flg); respond_flg=IPC_CREAT|0644; respond_key=202; respond_id=set_msq(respond_key,respond_flg); quit_flg=IPC_CREAT|0644; quit_key=250; quit_id=set_msq(quit_key,quit_flg); //注册信号量 w_key=301; a_key=302; p_key=303; sem_flg=IPC_CREAT|0644; sem_val=1; w_mtx=set_sem(w_key,sem_val,sem_flg); a_mtx=set_sem(a_key,sem_val,sem_flg); p_mtx=set_sem(p_key,sem_val,sem_flg); msg_arg.mid=getpid(); //设置等待 char temp; printf("输入任意字符结束等待:\n"); scanf("%c",&temp); int c_pid; //控制体 while(1){ //没有新顾客 if(count>0){ quest_flg=IPC_NOWAIT; if(msgrcv(quest_id,&msg_arg,sizeof(msg_arg),FINISHED,quest_flg)>=0){ count++; /*if(pipe(pipe1)<0||pipe(pipe2)) perror("pipe not create\n"); close(pipe1[1]); close(pipe2[0]); read(pipe1[0],&tran,sizeof(int)); c_pid=tran; write(pipe2[1],&tran,sizeof(int)); close(pipe1[0]); close(pipe2[1]);*/ // printf("%d barber finished working for %d customer\n",msg_arg.mid,c_pid); msg_arg.mtype=msg_arg.cmid; msgsnd(quit_id,&msg_arg,sizeof(msg_arg),0); } else if(msgrcv(quest_id,&msg_arg,sizeof(msg_arg),READERQUEST,quest_flg)>=0){ //有理发师请求工作 count--; msg_arg.mtype=msg_arg.mid; msgsnd(respond_id,&msg_arg,sizeof(msg_arg),0); printf("%d barber quest work\n",msg_arg.mid); } else if(msgrcv(quest_id,&msg_arg,sizeof(msg_arg),WRITERQUEST,quest_flg)>=0){ //有顾客到 w_mid=msg_arg.mid; count-=MAXVAL; while(count<0){ msgrcv(quest_id,&msg_arg,sizeof(msg_arg),FINISHED,0); count++; printf("%d barber finished\n",msg_arg.mid); } //允许顾客等待 msg_arg.mtype=w_mid; msgsnd(respond_id,&msg_arg,sizeof(msg_arg),0); printf("%d customer request wait\n",msg_arg.mid); } } if(count==0){ //有顾客在写pid msgrcv(quest_id,&msg_arg,sizeof(msg_arg),FINISHED,0); count=MAXVAL; //printf("%d\n",buff_ptr[0]); printf("%d customer finished write pid\n",msg_arg.mid); if(msgrcv(quest_id,&msg_arg,sizeof(msg_arg),READERQUEST,quest_flg)>=0){ count--; //long temp=msg_arg.mtype; msg_arg.mtype=msg_arg.mid; msgsnd(respond_id,&msg_arg,sizeof(msg_arg),0); printf("%d barber quest work\n",msg_arg.mid); //msg_arg.mtype=temp; } } } return EXIT_SUCCESS; }