生产者和消费者

#include <stdio.h>
#include <malloc.h>
#define buffersize 5//假设有5个缓冲区
int processnum=0;//初始化产品数量 
struct pcb /* 定义进程控制块PCB */
{  
   int flag;
   int numlabel;
   char product;
   char state;
   struct pcb* processlink; 
}*exe=NULL,*over=NULL;
typedef struct pcb PCB;
PCB* readyhead=NULL,* readytail=NULL;
PCB* consumerhead=NULL,* consumertail=NULL;
PCB* producerhead=NULL,* producertail=NULL;
int productnum=0;//产品数量
int full=0,empty=buffersize;//信号量
char buffer[buffersize];//缓冲区
int bufferpoint=0;//缓冲区指针
void linklist(PCB* p,PCB* listhead)//创建就绪队列
{
   PCB* cursor=listhead;
   while(cursor->processlink!=NULL){
      cursor=cursor->processlink;
   }
   cursor->processlink=p;
}
void freelink(PCB* linkhead)
{
   PCB* p;
   while(linkhead!=NULL)
   {
      p=linkhead;
      linkhead=linkhead->processlink;
      free(p);
   }
}
void linkqueue(PCB* process,PCB** tail)//初始化队列
{
   if((*tail)!=NULL)
   {
      (*tail)->processlink=process;
      (*tail)=process;
   }
   else {printf("队列未初始化！");}
}
PCB* getq(PCB* head,PCB** tail)
{
   PCB* p;
   p=head->processlink;
   if(p!=NULL)
   {
      head->processlink=p->processlink;
      p->processlink=NULL;
      if( head->processlink ==NULL )   (*tail)=head;
   }
   else  return NULL;
   return p;
}
bool processproc()//初始化进程
{
   int i,f,num;
   char ch;
   PCB* p=NULL;
   PCB** p1=NULL;
   printf("\n请输入希望产生的进程个数："); 
   scanf("%d",&num);
   getchar();
   for(i=0;i<num;i++)
   {
      printf("\n请输入您要产生的进程：输入1为生产者进程；输入2为消费者进程\n"); 
      scanf("%d",&f); 
      getchar();
      p=(PCB*)malloc(sizeof(PCB)) ;
      if( !p) {printf("内存分配失败");  return false; }
    p->flag=f;
    processnum++;
    p->numlabel=processnum;
    p->state='w';
    p->processlink=NULL;
    if(p->flag==1)
    {  printf("您要产生的进程是生产者，它是第%d个进程。请您输入您要该进程产生的字符：\n",processnum);
       scanf("%c",&ch);
       getchar();
       p->product=ch;
       productnum++;
       printf("您要该进程产生的字符是%c \n",p->product);
     }
     else { printf("您要产生的进程是消费者，它是第%d个进程。\n",p->numlabel);}
     linkqueue(p,&readytail);
     }
     return true;
}
bool hasElement(PCB* pro)//判断队列中是否有进程存在
{
   if(pro->processlink==NULL)  return false;
   else return true;
}
bool waitempty()//判断生产者等待队列是否为空
{
   if(empty<=0)
   {
      printf("进程%d:缓冲区存数，缓冲区满，该进程进入生产者等待队列\n",exe->numlabel); 
      linkqueue(exe,&producertail);
      return false;
   }
   else{  empty--;  return true; }
}
void signalempty()//唤醒生产者进程
{
   PCB* p;
   if(hasElement(producerhead)){
      p=getq(producerhead,&producertail);
      linkqueue(p,&readytail);
      printf("等待中的生产者进程进入就绪队列，它的进程号是%d\n",p->numlabel);
   }
   empty++; 
}
bool waitfull()//判断消费者等待队列是否为满
{
   if(full<=0)
   {
      printf("进程%d:缓冲区取数，缓冲区空，该进程进入消费者等待队列\n",exe->numlabel);
      linkqueue(exe,&consumertail);
      return false;
   }
   else{  full--;  return true;}
}
void signalfull()//唤醒消费者进程
{
   PCB* p;
   if(hasElement(consumerhead)){
      p=getq(consumerhead,&consumertail);
      linkqueue(p,&readytail);
      printf("等待中的消费者进程进入就绪队列，它的进程号是%d\n",p->numlabel);
   }
   full++;
}
void producerrun()//生产者进程
{
   if(!waitempty())  return;
   printf("进程%d开始向缓冲区存数%c\n",exe->numlabel,exe->product);
   buffer[bufferpoint]=exe->product;
   bufferpoint++;
   printf("进程%d向缓冲区存数操作结束\n",exe->numlabel);
   signalfull();
   linklist(exe,over);
}
void comsuerrun()//消费者进程
{
   if(!waitfull())  return;
   printf("进程%d开始向缓冲区取数\n",exe->numlabel);
   exe->product=buffer[bufferpoint-1];
   bufferpoint--;
   printf("进程%d向缓冲区取数操作结束，取数是%c\n",exe->numlabel,exe->product);
   signalempty();
   linklist(exe,over);
}
void display(PCB* p)//显示进程
{
   p=p->processlink;
   while(p!=NULL){
      printf("进程%d，它是一个",p->numlabel);
      p->flag==1? printf("生产者\n"):printf("消费者\n");
      p=p->processlink;
   }
}
void main()
{
   char terminate;
   bool element;
   printf("你想开始程序吗?(y/n)");
   scanf("%c",&terminate);
   getchar();
   readyhead=(PCB*)malloc(sizeof(PCB));//初始化队列
   if(readyhead==NULL) return;
   readytail=readyhead;
   readyhead->flag=3;
   readyhead->numlabel=processnum;
   readyhead->state='w';
   readyhead->processlink=NULL;
   consumerhead=(PCB*)malloc(sizeof(PCB));
   if(consumerhead==NULL) return;
   consumertail=consumerhead;
   consumerhead->processlink=NULL;
   consumerhead->flag=4;
   consumerhead->numlabel=processnum;
   consumerhead->state='w';
   consumerhead->processlink=NULL; 
   producerhead=(PCB*)malloc(sizeof(PCB));
   if(producerhead==NULL) return;
   producertail=producerhead;
   producerhead->processlink=NULL;
   producerhead->flag=5;
   producerhead->numlabel=processnum;
   producerhead->state='w';
   producerhead->processlink=NULL;
   over=(PCB*)malloc(sizeof(PCB));
   if(over==NULL) return;
   over->processlink=NULL;
   while(terminate=='y') 
   { 
      if(!processproc())  break;
      element=hasElement(readyhead);
      while(element){
        exe=getq(readyhead,&readytail);
        printf("进程%d申请运行，它是一个",exe->numlabel);
        exe->flag==1? printf("生产者\n"):printf("消费者\n");
        if(exe->flag==1)  producerrun();
        else comsuerrun();
        element=hasElement(readyhead);
   }
   printf("就绪队列没有进程\n");
   if(hasElement(consumerhead))
   {
      printf("消费者等待队列中有进程:\n");
      display(consumerhead);
   }
   else {  printf("消费者等待队列中没有进程\n");  }
   if(hasElement(producerhead))
   {  printf("生产者等待队列中有进程:\n");
      display(producerhead);
   }
   else {
      printf("生产者等待队列中没有进程\n");
   }
   printf("你想继续吗?(press 'y' for on)");
   scanf("%c",&terminate);
   getchar();
   } 
   printf("\n\n 进程模拟完成.\n"); 
   freelink(over);//释放空间
   over=NULL;
   freelink(readyhead);
   readyhead=NULL;
   readytail=NULL;
   freelink(consumerhead);
   consumerhead=NULL;
   consumertail=NULL;
   freelink(producerhead);
   producerhead=NULL;
   producertail=NULL;
   getchar();
}