东北大学操作系统实验三报告

1、操作系统实验报告班 级物联网1302班学 号姓 名实验 3 进程同步和通信 - 生产者和消费者问题模拟1. 目的：调试、修改、运行模拟程序，通过形象化的状态显示，使学生理解进程的概念，了解同 步和通信的过程， 掌握进程通信和同步的机制， 特别是利用缓冲区进行同步和通信的过程。 通过补充新功能，使学生能灵活运用相关知识，培养创新能力。2. 内容及要求：1) 调试、运行模拟程序。2) 发现并修改程序中不完善的地方。3) 修改程序，使用随机数控制创建生产者和消费者的过程。4) 在原来程序的基础上， 加入缓冲区的写互斥控制功能， 模拟多个进程存取一个公共缓冲 区，当有进程正在写缓冲区时，其他要访问该缓

2、冲区的进程必须等待，当有进程正在读取 缓冲区时，其他要求读取的进程可以访问，而要求写的进程应该等待。5) 完成 1) 、2) 、3)功能的,得基本分,完成 4)功能的加 2分,有其它功能改进的再加 2分3. 程序说明：本程序是模拟两个进程，生产者(producer )和消费者(Consumer)工作。生产者每次 产生一个数据，送入缓冲区中。消费者每次从缓冲区中取走一个数据。缓冲区可以容纳 8 个数据。因为缓冲区是有限的，因此当其满了时生产者进程应该等待，而空时，消费者进 程应该等待；当生产者向缓冲区放入了一个数据，应唤醒正在等待的消费者进程，同样， 当消费者取走一个数据后，应唤醒正在等待的生产

3、者进程。就是生产者和消费者之间的同每次写入和读出数据时，都将读和写指针加一。当读写指针同样时，又一起退回起点。当写指针指向最后时，生产者就等待。当读指针为零时，再次要读取的消费者也应该等待。为简单起见，每次产生的数据为 0-99 的整数，从 0 开始，顺序递增。两个进程的调度 是通过运行者使用键盘来实现的。4. 程序使用的数据结构进程控制块：包括进程名，进程状态和执行次数。缓冲区：一个整数数组。缓冲区说明块：包括类型，读指针，写指针，读等待指针和写等待指针。5. 程序使用说明启动程序后，如果使用 p 键则运行一次生产者进程，使用 c 键则运行一次消费者进程。通过屏幕可以观察到两个进程的状态和缓

4、冲区变化的情况。6. 实验流程图源程序#include#include #include#define PIPESIZE 8enum Status RUN, WAIT, READY ;#define NORMAL 0#define SLEEP 1#define AWAKE 2struct PCBchar name3;enum Status status;int time;struct waitqueuestruct PCB pcb;struct waitqueue *next;struct PCB *producer; /* write wait point */struct PCB *con

5、sumer; /* read wait point */struct waitqueue *headerqueue, *tailqueue;int writeptr;int readptr;int writein, readout;int bufferPIPESIZE;int empty, full;void runp(char in3), runc(char in3), print();int main()char in3;writeptr = 0;readptr = 0;writein = 0;empty = PIPESIZE;full = 0;producer = (struct PCB

6、 *)malloc(sizeof(struct PCB);consumer = (struct PCB *)malloc(sizeof(struct PCB);headerqueue = (struct waitqueue *)malloc(sizeof(struct waitqueue); headerqueue-next = NULL;tailqueue = headerqueue;producer-status = READY;consumer-status = WAIT;producer-time = consumer-time = 0;printf(Now starting the

7、program!n);printf(Press p1 to run PRODUCER1,Press p1 to run PRODUCER2 n);printf(Press c1 to run CONSUMER1,Press c2 to run CONSUMER2 n); printf(Press e to exit from the program.n);while (1)strcpy(in, N);while (!strcmp(in, N)printf(n);scanf(%s, in);&strcmp(in,if (strcmp(in, e) &strcmp(in, p1) &strcmp(

8、in, p2) c1) & strcmp(in, c2)printf(error,please input again!n);strcpy(in, N);if (p = in0)runp(in);producer-time+;else if (c = in0)runc(in);consumer-time+;elsen, in);struct waitqueue *p = (struct waitqueue *)malloc(sizeof(struct waitqueue);strcpy(p-, in);p- = WAIT;p- = producer-time + 1;p-next = NULL

9、;tailqueue-next = p;tailqueue = p;full+;elsewritein = (writein + 1) % 100;producer-status = RUN;printf(run PRODUCER %s process . product %d , in, writein);bufferwriteptr = writein;if (empty8)struct waitqueue *p;p = headerqueue-next;printf(run CONSUMER %s process. use %d, p-, bufferwriteptr);if (tail

10、queue = p)tailqueue = headerqueue;headerqueue-next = p-next;free(p);consumer-status = WAIT;empty-;elseif (writeptr readptr)writeptr+;if (writeptr = PIPESIZE)writeptr = 0;if (readptr = 0)producer-status = WAIT;else producer-status = READY;elsewriteptr+;if (writeptr = readptr)producer-status = WAIT;el

11、se producer-status = READY;consumer-status = READY;empty-;full+;void runc(char in3)if (empty = 8)struct waitqueue *search; search = headerqueue-next; while (search != NULL)if (!strcmp(in, search-)printf(error!n);exit(1);search = search-next;consumer-status = WAIT;printf(CONSUMER %s is waiting, cant

12、be scheduled.n,in);struct waitqueue *p = (struct waitqueue *)malloc(sizeof(struct waitqueue);strcpy(p-, in);p- = WAIT;p- = consumer-time + 1;p-next = NULL;tailqueue-next = p;tailqueue = p;empty+;elseconsumer-status = RUN;readout = bufferreadptr;printf(run CONSUMER %s process. use %d , in, readout);i

13、f (full8) writein = (writein + 1) % 100; bufferwriteptr = writein; struct waitqueue *p;p = headerqueue-next;printf(run PRODUCER %sprocess. product %d, p-, bufferwriteptr); if (tailqueue = p)tailqueue = headerqueue;headerqueue-next = p-next;free(p);producer-status = WAIT;full-;writeptr+;readptr+;else

14、if (readptr writeptr)readptr+;if (readptr = PIPESIZE)readptr = 0;if (writeptr = 0)consumer-status = WAIT;elseconsumer-status = READY;else consumer-status = READY;elsereadptr+;if (readptr = writeptr)consumer-status = WAIT;writeptr = readptr = 0;else consumer-status = READY;producer-status = READY;ful

15、l-;empty+;void print()int i = 0;int j = 0;int low = 0;int high = 0;printf(n);for (i; i PIPESIZE; i+)printf();printf(n);if (readptr writeptr)for (low = 0; low readptr; low+) printf(| |);for (low = readptr; low writeptr; low+)printf(| %2d|, bufferlow);for (low = writeptr; low writeptr)for (low = 0; lo

16、w writeptr; low+)printf(| %2d |, bufferlow);for (low = writeptr; low readptr; low+) printf(| |);for (low = readptr; low status = WAIT)for (low = 0; low PIPESIZE; low+)printf(| %2d |, bufferlow);elsefor (low = 0; low PIPESIZE; low+)printf(| |);printf(n);for (i = 0; i status = WAIT & NULL !=headerqueue-next) struct waitqueue *p = headerqueue-next;while (NULL != p)printf( PRODUCER %s proc