东北大学-操作系统实验三分析报告

东北大学-操作系统实验三报告————————————————————————————————作者：————————————————————————————————日期：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者进程。

就是生产者和消费者之间的同步。

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冲区变化的情况。

6.实验流程图开始初始化进程控制块初始化生产者进程初始化消费者进程进程调度调度生产者进程？调度消费者进程？n n生产者处于阻塞状态结束调度？结束nyyn结束y缓存区已满？生产者进程被阻塞yn 消费者处于阻塞y结束y缓冲区为空？nn消费者被阻塞往缓冲区添加一个数据生产者添加数据指针移到下一个位置下一个位置>8下一个位置值0有消费者进程被阻塞调用消费者进程nyy消费缓冲区里的一个数据有生产者进程被阻塞调用生产者进程消费者进程消费指针移到下一个位置消费者进程指针与生产者进程指针相同两个指针均置0y下一位置置0下一个位置>8nynynn缓冲区可用？y阻塞该生产者n缓冲区可用？阻塞该消费者ny源程序#include<stdio.h>#include<stdlib.h>#include<string.h>#define PIPESIZE 8enum Status { RUN, WAIT, READY };#define NORMAL 0#define SLEEP 1#define AWAKE 2struct PCB{char name[3];enum Status status;int time;};struct waitqueue{struct PCB pcb;struct waitqueue *next;};struct PCB *producer; /* write wait point */struct PCB *consumer; /* read wait point */ struct waitqueue *headerqueue, *tailqueue;int writeptr;int readptr;int writein, readout;int buffer[PIPESIZE];int empty, full;void runp(char in[3]), runc(char in[3]), print();int main(){char in[3];writeptr = 0;readptr = 0;writein = 0;empty = PIPESIZE;full = 0;producer = (struct PCB *)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 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);if (strcmp(in, "e") && strcmp(in, "p1") && strcmp(in, "p2") && strcmp(in, "c1") && strcmp(in, "c2")){printf("error,please input again!!!\n");strcpy(in, "N");}}if ('p' == in[0]){runp(in);producer->time++;}else if ('c' == in[0]){runc(in);consumer->time++;}else{//printf("PRODUCER product %d times\n", producer->time);//printf("CONSUMER consumer %d times\n", consumer->time);exit(0);}print();printf("\n");}}void runp(char in[3]){if (full >= 8){struct waitqueue *search;search = headerqueue->next;while (search != NULL){if (!strcmp(in, search->)){printf("error!!!\n");exit(1);}search = search->next;}producer->status = WAIT;printf("PRODUCER %s process is waiting, can't be scheduled.\n", in);struct waitqueue *p = (struct waitqueue *)malloc(sizeof(struct waitqueue));strcpy(p->, in);p->pcb.status = WAIT;p->pcb.time = producer->time + 1;p->next = NULL;tailqueue->next = p;tailqueue = p;full++;}else{writein = (writein + 1) % 100;producer->status = RUN;printf("run PRODUCER %s process . product %d ", in, writein);buffer[writeptr] = writein;if (empty>8){struct waitqueue *p;p = headerqueue->next;printf("run CONSUMER %s process. use %d", p->, buffer[writeptr]);if (tailqueue == p){tailqueue = headerqueue;}headerqueue->next = p->next;free(p);consumer->status = WAIT;empty--;}else{if (writeptr > readptr){writeptr++;if (writeptr >= PIPESIZE){writeptr = 0;if (readptr == 0)producer->status = WAIT;else producer->status = READY;}}else{writeptr++;if (writeptr == readptr)producer->status = WAIT;else producer->status = READY;}consumer->status = READY;empty--;full++;}}}void runc(char in[3]){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, can't be scheduled.\n",in);struct waitqueue *p = (struct waitqueue *)malloc(sizeof(struct waitqueue));strcpy(p->, in);p->pcb.status = WAIT;p->pcb.time = consumer->time + 1;p->next = NULL;tailqueue->next = p;tailqueue = p;empty++;}else{consumer->status = RUN;readout = buffer[readptr];printf("run CONSUMER %s process. use %d ", in, readout);if (full>8){writein = (writein + 1) % 100;buffer[writeptr] = writein;struct waitqueue *p;p = headerqueue->next;printf("run PRODUCER %s process. product %d ", p->, buffer[writeptr]);if (tailqueue == p){tailqueue = headerqueue;}headerqueue->next = p->next;free(p);producer->status = WAIT;full--;writeptr++;readptr++;}else{if (readptr > writeptr){readptr++;if (readptr >= PIPESIZE){readptr = 0;if (writeptr == 0)consumer->status = WAIT;elseconsumer->status = READY;}else consumer->status = READY;}else{readptr++;if (readptr == writeptr){consumer->status = WAIT;writeptr = readptr = 0;}else consumer->status = READY;producer->status = READY;}full--;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 |", buffer[low]);}for (low = writeptr; low <PIPESIZE; low++) printf("| |");}else if (readptr > writeptr){for (low = 0; low < writeptr; low++)printf("| %2d |", buffer[low]);for (low = writeptr; low < readptr; low++) printf("| |");for (low = readptr; low < PIPESIZE; low++) {printf("| %2d |", buffer[low]);}}else if (producer->status == WAIT){for (low = 0; low < PIPESIZE; low++){printf("| %2d |", buffer[low]);}}else{for (low = 0; low < PIPESIZE; low++){printf("| |");}}printf("\n");for (i = 0; i < PIPESIZE; i++)printf("--------");printf("\n");if (producer->status == WAIT && NULL !=headerqueue->next){struct waitqueue *p = headerqueue->next;while (NULL != p){printf(" PRODUCER %s process are waitting\n", p->);p = p->next;}}elseprintf("PRODUCER ready \n");if (consumer->status == WAIT &&headerqueue->next){struct waitqueue *p = headerqueue->next;while (NULL != p){printf(" CONSUMER %s process are waitting\n", p->);p = p->next;}}elseprintf("CONSUMER ready\n ");}实验结果：。