操作系统的上机实验报告代码，这里分享给大家：
#include<stdio.h>
#include<stdlib.h>
#define PROCESS_NAME_LEN 32 /*进程名称的最大长度*/
#define MIN_SLICE 10 /*最小碎片的大小*/
#define DEFAULT_MEM_SIZE 1024 /*默认内存的大小*/
#define DEFAULT_MEM_START 0 /*默认内存的起始位置*/
/* 内存分配算法 */
#define MA_FF 1
#define MA_BF 2
#define MA_WF 3
/*描述每一个空闲块的数据结构*/
struct free_block_type{
int size;
int start_addr;
struct free_block_type *next;
};
/*指向内存中空闲块链表的首指针*/
struct free_block_type *free_block;
/*每个进程分配到的内存块的描述*/
struct allocated_block{
int pid; /*进程pid*/
int size; /*内存块大小*/
int start_addr; /*开始地址*/
char process_name[PROCESS_NAME_LEN]; /*进程名*/
struct allocated_block *next;
};
/*进程分配内存块链表的首指针*/
struct allocated_block *allocated_block_head = NULL;
int mem_size=DEFAULT_MEM_SIZE; /*内存大小*/
int ma_algorithm = MA_FF; /*当前分配算法*/
static int pid = 0; /*初始pid*/
int flag = 0; /*设置内存大小标志*/
/*函数声明*/
struct free_block_type* init_free_block(int mem_size);
void display_menu();
int set_mem_size();
void set_algorithm();
void rearrange(int algorithm);
void rearrange_FF();
void rearrange_BF();
void rearrange_WF();
int new_process();
int allocate_mem(struct allocated_block *ab);
void kill_process();
int free_mem(struct allocated_block *ab);
int dispose(struct allocated_block *free_ab);
int display_mem_usage();
void do_exit();
void swap(int* , int*);
struct allocated_block *find_process(int);
struct allocated_block *find_process(int pid)
{
struct allocated_block *p;
p = allocated_block_head;
while(p!= NULL)
{
if(p->pid == pid)
{
return p;
}
p = p->next;
}
return NULL;
}
void swap(int *a,int *b)
{
int tmp;
tmp = *a;
*a = *b;
*b = tmp;
}
void do_exit()
{
}
int main()
{
int a = 10;
int b = 20;
swap(&a,&b);
char choice;
pid=0;
free_block = init_free_block(mem_size); //初始化空闲区
for(;;)
{
display_menu(); //显示菜单
fflush(stdin);
choice=getchar(); //获取用户输入
switch(choice)
{
case '1': set_mem_size(); break; //设置内存大小
case '2': set_algorithm();flag=1; break; //设置分配算法
case '3': new_process(); flag=1; break; //创建新进程
case '4': kill_process();flag=1; break; //删除进程
case '5': display_mem_usage(); flag=1; break; //显示内存使用
case '0': do_exit(); exit(0); //释放链表并退出
default: break;
}
getchar();
}
}
/*初始化空闲块，默认为一块，可以指定大小及起始地址*/
struct free_block_type* init_free_block(int mem_size)
{
struct free_block_type *fb;
fb=(struct free_block_type *)malloc(sizeof(struct free_block_type));
if(fb==NULL)
{
printf("No mem\n");
return NULL;
}
fb->size = mem_size;
fb->start_addr = DEFAULT_MEM_START;
fb->next = NULL;
return fb;
}
/*显示菜单*/
void display_menu()
{
printf("\n");
printf("1 - Set memory size (default=%d)\n", DEFAULT_MEM_SIZE);
printf("2 - Select memory allocation algorithm\n");
printf("3 - New process \n");
printf("4 - Terminate a process \n");
printf("5 - Display memory usage \n");
printf("0 - Exit\n");
}
/*设置总内存的大小*/
int set_mem_size()
{
int size;
if(flag!=0) //防止重复设置
{
printf("Cannot set memory size again\n");
return 0;
}
printf("Total memory size =");
scanf("%d", &size);
if(size>0)
{
mem_size = size;
free_block->size = mem_size;
}
flag=1;
return 1;
}
/* 设置当前的分配算法 */
void set_algorithm()
{
int algorithm;
printf("\t1 - First Fit\n");
printf("\t2 - Best Fit \n");
printf("\t3 - Worst Fit \n");
scanf("%d", &algorithm);
if(algorithm>=1 && algorithm <=3)
ma_algorithm=algorithm;
//按指定算法重新排列空闲区链表
rearrange(ma_algorithm);
}
/*按指定的算法整理内存空闲块链表*/
void rearrange(int algorithm)
{
switch(algorithm)
{
case MA_FF: rearrange_FF(); break;
case MA_BF: rearrange_BF(); break;
case MA_WF: rearrange_WF(); break;
}
}
/*按FF算法重新整理内存空闲块链表*/
void rearrange_FF()
{
struct free_block_type *tmp, *work;
printf("Rearrange free blocks for FF \n");
tmp = free_block;
while(tmp!=NULL)
{
work = tmp->next;
while(work!=NULL)
{
if( work->start_addr < tmp->start_addr) /*地址递增*/
{
printf("%d %d",work->start_addr,tmp->start_addr);
swap(&work->start_addr, &tmp->start_addr);
swap(&work->size, &tmp->size);
printf("%d %d",work->start_addr,tmp->start_addr);
}
work=work->next;
}
tmp=tmp->next;
}
}
/*按BF算法重新整理内存空闲块链表*/
void rearrange_BF()
{
//请自行补充
struct free_block_type *tmp, *work;
printf("Rearrange free blocks for BF \n");
tmp = free_block;
while(tmp!=NULL)
{
work = tmp->next;
while(work!=NULL)
{
if( work->size < tmp->size) /*内存大小递增*/
{
printf("%d %d",work->start_addr,tmp->start_addr);
swap(&work->start_addr, &tmp->start_addr);
swap(&work->size, &tmp->size);
printf("%d %d",work->start_addr,tmp->start_addr);
}
work=work->next;
}
tmp=tmp->next;
}
}
/*按WF算法重新整理内存空闲块链表*/
void rearrange_WF()
{
//请自行补充
struct free_block_type *tmp, *work;
printf("Rearrange free blocks for WF \n");
tmp = free_block;
while(tmp!=NULL)
{
work = tmp->next;
while(work!=NULL)
{
if( work->size > tmp->size) /*地址递减*/
{
swap(&work->start_addr, &tmp->start_addr);
swap(&work->size, &tmp->size);
}
work=work->next;
}
tmp=tmp->next;
}
}
/*创建新的进程，主要是获取内存的申请数量*/
int new_process()
{
struct allocated_block *ab;
int size;
int ret;
ab=(struct allocated_block *)malloc(sizeof(struct allocated_block));
if(!ab)
{
exit(-5);
}
ab->next = NULL;
pid++;
sprintf(ab->process_name, "PROCESS-%02d", pid);
ab->pid = pid;
printf("Memory for %s:", ab->process_name);
scanf("%d", &size);
if(size>0)
{
ab->size=size;
}
ret = allocate_mem(ab); /* 从空闲区分配内存，ret==1表示分配ok*/
/*如果此时allocated_block_head尚未赋值，则赋值*/
if((ret==1) && (allocated_block_head == NULL))
{
allocated_block_head=ab;
return 1;
}/*分配成功，将该已分配块的描述插入已分配链表*/
else if (ret==1)
{
ab->next=allocated_block_head;
allocated_block_head=ab;
return 2;
}
else if(ret==-1) /*分配不成功*/
{
printf("Allocation fail\n");
free(ab);
return -1;
}
return 3;
}
/*分配内存模块*/
int allocate_mem(struct allocated_block *ab)
{
struct free_block_type *fbt, *pre;
int request_size=ab->size;
fbt = pre = free_block;
while(fbt!=NULL)
{
if(fbt->size>=request_size)/*分配后空闲空间足够大，则分割*/
{
//自行补充********
ab->start_addr = fbt->start_addr;
fbt->start_addr += request_size;
fbt->size-= request_size;
return 1;
}
pre = fbt;
fbt = fbt->next;
}
return -1;
}
/*删除进程，归还分配的存储空间，并删除描述该进程内存分配的节点*/
void kill_process()
{
struct allocated_block *ab;
int pid;
printf("Kill Process, pid=");
scanf("%d", &pid);
ab=find_process(pid);
if(ab!=NULL)
{
free_mem(ab); /*释放ab所表示的分配区*/
dispose(ab); /*释放ab数据结构节点*/
}
}
/*将ab所表示的已分配区归还，并进行可能的合并*/
int free_mem(struct allocated_block *ab)
{
int algorithm = ma_algorithm;
struct free_block_type *fbt, *pre, *work;
fbt=(struct free_block_type*) malloc(sizeof(struct free_block_type));
if(!fbt)
{
return -1;
}
fbt->size = ab->size;
fbt->start_addr = ab->start_addr;
/*插入到空闲区链表的头部并将空闲区按地址递增的次序排列*/
fbt->next = free_block;
free_block=fbt;
rearrange(MA_FF);
pre=free_block;
while(pre!=NULL)
{
work = pre->next;
if(work!=NULL)
{
/*如果当前空闲区与后面的空闲区相连，则合并*/
if(pre->start_addr+pre->size == work->start_addr)
{
pre->size += work->size;
pre->next = work->next;
free(work);
continue;
}
}
pre = pre->next;
}
rearrange(algorithm); /*重新按当前的算法排列空闲区*/
return 1;
}
/*释放ab数据结构节点*/
int dispose(struct allocated_block *free_ab)
{
struct allocated_block *pre, *ab;
if(free_ab == allocated_block_head) /*如果要释放第一个节点*/
{
allocated_block_head = allocated_block_head->next;
free(free_ab);
return 1;
}
pre = allocated_block_head;
ab = allocated_block_head->next;
while(ab!=free_ab)
{
pre = ab; ab = ab->next;
}
pre->next = ab->next;
free(ab);
return 2;
}
int display_mem_usage()
{
struct free_block_type *fbt=free_block;
struct allocated_block *ab=allocated_block_head;
if(fbt==NULL)
return(-1);
printf("----------------------------------------------------------\n");
/* 显示空闲区 */
printf("Free Memory:\n");
printf("%20s %20s\n", " start_addr", " size");
while(fbt!=NULL)
{
printf("%20d %20d\n", fbt->start_addr, fbt->size);
fbt=fbt->next;
}
/* 显示已分配区 */
printf("\nUsed Memory:\n");
printf("%10s %20s %10s %10s\n", "PID", "ProcessName", "start_addr", " size");
while(ab!=NULL)
{
printf("%10d %20s %10d %10d\n", ab->pid, ab->process_name, ab->start_addr, ab->size);
ab=ab->next;
}
printf("----------------------------------------------------------\n");
return 0;
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