作业调度C语言编写,OS作业调度C语言实现

SJF、FCFS、FPF算法：

#include "stdio.h"

#include "stdlib.h"

#include "stdio.h"

#include "conio.h"

#define getjcb(type) (type*)malloc(sizeof(type))

int n = 0, time = 0; float eti, ewi;

struct jcb {

char name[10]; /* 作业名 */

char state; /* 作业状态 */

int pn; /*优先级*/

int ts; /* 提交时间 */

int tb; /* 开始运行时间 */

int tc; /* 完成时间 */

float ti; /* 周转时间 */

float wi; /* 带权周转时间 */

int ntime; /* 作业所需运行时间 */

char resource[10]; /* 所需资源 */

struct jcb *link; /* 结构体指针 */

} *p, *q, *head = NULL;

typedef struct jcb JCB;

void initial() {

int i;

printf("\nInput jcb num\n");

scanf("%d", &n);

printf("Input\nname\tpn\tts\tntime\tresource\n");

for (i = 0; i < n; i++) {

p = getjcb(JCB);

scanf("%s\t%d\t%d\t%d\t%s", &p->name,&p->pn, &p->ts, &p->ntime, &p->resource);

p->state = 'W';

p->link = NULL;

if (head == NULL) head = q = p;

else {

q->link = p;

q = p;

}

}

}

void print(JCB *pr) {

JCB *p=(JCB*)malloc(sizeof(*pr));

printf("\ntime=%d", time);

printf("\nname\tstate\tpn\tts\tntime\tsource\ttb\ttc\tti\twi\n");

printf("%s\t%c\t%d\t%d\t%s\t%d\t%d\t%4.2f\t%4.2f\t%d\n",

pr->name, pr->state, pr->ts, pr->ntime, pr->resource, pr->tb, pr->tc, pr->ti, pr->wi,p->pn );

p = head;

do {

if (p->state == 'W')

printf("%s\t%c\t%d\t%d\t%s\t%d\n",

p->name, p->state, p->ts, p->ntime, p->resource, p->pn);

p = p->link;

} while (p != NULL);

p = head;

do {

if (p->state == 'F')

printf("%s\t%c\t%d\t%d\t%s\t%d\t%d\t%4.2f\t%4.2f\t%d\n",

pr->name, pr->state, pr->ts, pr->ntime, pr->resource, pr->tb, pr->tc, pr->ti, pr->wi, p->pn);

p = p->link;

} while (p != NULL);

}

void running(JCB *p) { //计算

p->tb = time; p->state = 'R';

p->tc = p->tb + p->ntime;

p->ti = (float)(p->tc - p->ts);

p->wi = (float)(p->ti / p->ntime);

eti += p->ti;

ewi += p->wi;

print(p);

time += p->ntime;

p->state = 'F';

printf("\n%s has been finished!\npress any key to continue...\n", p->name);

_getch();

}

void last() {

eti /= n; ewi /= n;

printf("\neti=%7.3f\tewi=%7.3f\n", eti, ewi);

}

void sjf() {

JCB *min;

int i, iden;

for (i = 0; i < n; i++) {

p = min = head; iden = 1;

do {

if (p->state == 'W'&&p->ts <= time) //查找短时间

if (iden) {

min = p; iden = 0;

}

else if (p->ntime < min->ntime) min = p;

p = p->link;

} while (p != NULL);

if (iden) {

i--; printf("\ntime=%d:\tno JCB submib...wait...", time); time++;

if (time > 100) { printf("\nruntime is too long...error"); _getch(); }

}

else {

running(min);

}

}

}

void fcfs() {

JCB *min;

int i, iden;

for (i = 0; i < n; i++) {

p = min = head; iden = 1;

do {

if (p->state == 'W'&&p->ts <= time)

if (iden) {

min = p; iden = 0;

}

else if (p->ts < min->ts) min = p;

p = p->link;

} while (p != NULL);

if (iden) {

i--; printf("\ntime=%d:\tno JCB submib...wait...", time); time++;

if (time > 100) { printf("\nruntime is too long...error"); _getch(); }

}

else {

running(min);

}

}

}

void fpf() {

JCB *min;

int i, iden;

for (i = 0; i < n; i++) {

p = min = head; iden = 1;

do {

if (p->state == 'W'&&p->ts <= time) //查找短时间

if (iden) {

min = p; iden = 0;

}

else if (p->pn pn)

min = p;

p = p->link;

} while (p != NULL);

if (iden) {

i--; printf("\ntime=%d:\tno JCB submib...wait...", time); time++;

if (time > 100) { printf("\nruntime is too long...error"); _getch(); }

}

else {

running(min);

}

}

}

void runjcb(int m) {

printf("\n\nstart running jcb use algorithm %d.", m);

switch (m) {

case 1:fcfs(); break;

case 2:sjf(); break;

case 3:fpf(); break;

default:printf("\nrunjcb error...\n"); exit(1);

}

}

void start() {

int m;

char str[100] = "\nselect algorithm\n1.FCFS\n2.SJF\n3.FPF\n";

printf("%s", str);

m = _getch() - 48;

initial();

if (1 <= m && m <= 3) runjcb(m);

else {

printf("\nselect error!try again...\n");

start();

}

last();

}

int main() {

start();

printf("\nfinished!");

_getch();

return 0;

}

计算结果：

FCFS:

SJF:

FPF:

第三个FPF实现有问题，带权周转时间wi不能正确计算，烦请大佬看看吧