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/*
*Author:Mr Sunny
*Time:Oct 2010
*
*/
#include
#include
#include
#include
#define N 3
enum state {
e, r, t, w, c
};
struct PCB {
int id, priority, runningtime;
enum state status;
char name[10];
struct PCB *next;
}pro[N];
//分别代表各个状态队列的头指针
struct PCB * hready;
struct PCB * lready;
struct PCB * wait;
struct PCB * execute;
struct PCB * complete;
struct semaphore {
int id, value;
}s1, s2;
int process_init(); //进程初始化
int insert_queue(struct PCB **head, struct PCB * id); //将id进程添加到head的头队列
int schedule(); //进程调度函数
int pro_running();
int main()
{
process_init();
printf("The %d process have been ready,we can GO!!\n", N);
sleep(1);
while(1) {
schedule();
pro_running();
}
return 0;
}
int schedule()
{
//先查找高就绪队列中的进程
if(hready != NULL) {
execute = hready;
hready = hready->next;
// execute->next = NULL;
return 0;
}
//再查找低就绪队列中的进程
if(lready != NULL) {
// insert_queue(&hready, lready);
hready = lready;
lready = lready->next;
hready->next = NULL;
// hready->next = NULL;
sun_wakeup();
return 0;
}
//说明所有进程运行完毕
}
int pro_running()
{
int i, slice;
printf("%d号进程正在运行!\n", execute->id);
for(slice = execute->runningtime; slice > 0; slice--) {
printf("\t这个进程还剩%d个时间片\n", slice);
}
sleep(1);
printf("%d号进程运行完毕!\n\n", execute->id);
insert_queue(&lready, execute);
// sun_wakeup();
return 0;
}
int sun_wakeup()
{
execute = hready;
hready = hready->next;
return 0;
}
int process_init()
{
int i;
hready = lready = wait = execute = complete = NULL;
for(i = 0; i < N; i++) {
insert_queue(&hready, &pro[i]);
pro[i].id = i;
pro[i].runningtime = i+2;
pro[i].status = r;
pro[i].priority = i;
strcpy(pro[i].name, "苹果");
}
return 0;
}
int insert_queue(struct PCB **head, struct PCB *id)
{
struct PCB *p;
id->next = NULL;
if((*head) == NULL) {
*head = id;
return 0;
} else {
for(p = *head; p->next != NULL; p = p->next);
p->next = id;
}
return 0;
}
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