这次实现没有涉及进程的blocked状态！
#include<stdio.h> #include<string.h> #include<stdlib.h> #include<math.h> #include<stdbool.h> #include<time.h> int identifier_allocate = 0; // 进程现场信息 typedef struct Context_Data{ int PC; // Program Counter int IR; // Instruction Register int AC; // Accumulator }CD; //定义Process Control Block typedef struct PCB{ int identifier; //进程标识符 int status; //进程状态，0代表new，1代表ready，2代表running，3代表blocked，4代表exit int runtime; //运行时间 int memory_pointer; //内存地址 CD context_data; //进程现场信息 int priority; // 权值 }PCB; //队列节点 typedef struct QueueNode{ PCB pcb; struct QueueNode *next; }QueueNode; //队列 typedef struct Queue{ QueueNode *front; QueueNode *rear; }Queue; //对于权值不同的进程分别设置不同的队列 Queue Ready_Queue_Priority1, Ready_Queue_Priority2, Ready_Queue_Priority3; //初始化队列 int InitQueue(Queue *Q){ Q->front = (QueueNode *)malloc(sizeof(QueueNode)); if(Q->front == NULL){ return 0; } Q->front->next = NULL; Q->rear = Q->front; return 1; } //进队列 int EnterQueue(Queue *Q, PCB *x){ QueueNode *newnode = (QueueNode *)malloc(sizeof(QueueNode)); if(newnode != NULL){ newnode->pcb = *x; newnode->next = NULL; Q->rear->next = newnode; Q->rear = newnode; return 1; } return 0; } //队头出队列 int DeleteQueue(Queue *Q, PCB *x){ if(Q->front == Q->rear){ return 0; } QueueNode *p; p = Q->front->next; Q->front->next = p->next; if(Q->rear == p){ Q->rear = Q->front; } *x = p->pcb; free(p); return 1; } //判断队列是否为空 bool isEmpty(Queue *Q){ if(Q->front == Q->rear){ return true; } return false; } //创建进程 void Create(){ printf("请输入要创建进程的个数："); int NumOfProcessToBeCreated = 0; scanf("%d", &NumOfProcessToBeCreated); int i = 0; bool failed = false;//用户创建进程时是否出错 for(i = 0; i < NumOfProcessToBeCreated; i++){ printf("请输入该进程运行时间（单位s）和优先级（数字用一个空格隔开；1，2，3优先级递减）： "); PCB process; scanf("%d %d", &process.runtime, &process.priority); //除了进程运行时间和权值时输入，其他值全部随机生成 if(!failed){ process.identifier = ++identifier_allocate; srand((unsigned)time(NULL)); process.context_data.AC = rand(); process.context_data.IR = rand(); process.context_data.PC = rand(); process.memory_pointer = rand(); //设置进程状态new process.status = 0; } //对于权值不同的进程分别放入不同的队列中，并且设置进程状态为ready if(process.priority == 1){ process.status = 1; EnterQueue(&Ready_Queue_Priority1, &process); failed = false; } else if(process.priority == 2){ process.status = 1; EnterQueue(&Ready_Queue_Priority2, &process); failed = false; } else if(process.priority == 3){ process.status = 1; EnterQueue(&Ready_Queue_Priority3, &process); failed = false; } //若输入错误，该进程不放入队列，重新输入信息，并且把failed置为true else{ printf("该进程创建失败！（输入权值错误）。请重新输入！ "); NumOfProcessToBeCreated++; failed = true; } } } //展示ready队列中进程的ID void display(){ int i = 0; QueueNode *node; node = Ready_Queue_Priority1.front->next; printf(" 权值为1的ready队列进程ID:"); while(node != NULL){ printf("%d ", node->pcb.identifier); node = node->next; } node = Ready_Queue_Priority2.front->next; printf(" 权值为2的ready队列进程ID:"); while(node != NULL){ printf("%d ", node->pcb.identifier); node = node->next; } node = Ready_Queue_Priority3.front->next; printf(" 权值为3的ready队列进程ID:"); while(node != NULL){ printf("%d ", node->pcb.identifier); node = node->next; } printf(" "); } //终止函数 void Terminate(PCB *process){ //将status置为4，输出相应的信息 process->status = 4; printf(" 进程%d执行完毕，退出！ ", process->identifier); } //调度策略，对于CPU来说采用时间片轮转的策略，对于选择进程HPF策略 void Schedule(){ PCB Running_Process; //若三个队列有一个不为空进程便要一直进行下去 while(!(isEmpty(&Ready_Queue_Priority1) && isEmpty(&Ready_Queue_Priority2) && isEmpty(&Ready_Queue_Priority3))){ //依据权值按顺序进行检查 if(!isEmpty(&Ready_Queue_Priority1)){ DeleteQueue(&Ready_Queue_Priority1, &Running_Process); } else if(!isEmpty(&Ready_Queue_Priority2)){ DeleteQueue(&Ready_Queue_Priority2, &Running_Process); } else{ DeleteQueue(&Ready_Queue_Priority3, &Running_Process); } /*将进程状态改为正在运行的的状态 */ Running_Process.status = 2; /*输出正在运行进程的状态信息*/ printf(" 进程%d正在运行...... ", Running_Process.identifier); printf("ID 状态 运行时间 内存地址 权值 PC IR AC "); printf("%-10d %-6d %-7d %-14d %-8d %-2d %-2d %-2d ", Running_Process.identifier, Running_Process.status, Running_Process.runtime, Running_Process.memory_pointer, Running_Process.priority, Running_Process.context_data.PC, Running_Process.context_data.IR, Running_Process.context_data.AC); display(); /* 对于本程序，采用4s为一个时间片 若一个进程剩余的运行时间不足一个时间片，就执行相应的时间即可； 就直接执行一个时间片，若剩余运行时间为0，便时改进程退出 */ if(Running_Process.runtime < 4 && Running_Process.runtime > 0){ Sleep(Running_Process.runtime * 1000); Running_Process.runtime = 0; } else{ Sleep(4000); Running_Process.runtime -= 4; } if(Running_Process.runtime == 0){ Terminate(&Running_Process); } /* 若进程为运行结束，按照起权值再次放入相应的队列中去并且设置其状态为ready */ if(Running_Process.priority == 1 && Running_Process.status == 2){ Running_Process.status = 1; EnterQueue(&Ready_Queue_Priority1, &Running_Process); } else if(Running_Process.priority == 2 && Running_Process.status == 2){ Running_Process.status = 1; EnterQueue(&Ready_Queue_Priority2, &Running_Process); } else if(Running_Process.priority == 3 && Running_Process.status == 2){ Running_Process.status = 1; EnterQueue(&Ready_Queue_Priority3, &Running_Process); } } } int main(){ InitQueue(&Ready_Queue_Priority1); InitQueue(&Ready_Queue_Priority2); InitQueue(&Ready_Queue_Priority3); while(1){ Create(); Schedule(); } return 0; }