一个简单的内存分配算法

文件:	qq.zip
大小:	127KB
下载:	下载

果然不到50行，果然可以在2小时上机写完，管然面试让15分钟写出来不过分
const int SEG_LEN = 128-4;
struct Mem_seg
{
    char mem [SEG_LEN];
    Mem_seg * next;
};

struct Mem_list
{
    Mem_list(Mem_seg *h, Mem_seg *e)
        :head(h),end(e)
    {
    }
    Mem_seg * head;
    Mem_seg * end;
};

Mem_list mem_init(char * all_mem, int free_size)
{
    int seg_num = free_size / SEG_LEN;
    for(int i=0;i        ((Mem_seg *)&all_mem[i * SEG_LEN])->next=(Mem_seg *)&all_mem[(i+1)*SEG_LEN];
    return Mem_list((Mem_seg *)all_mem,(Mem_seg *)&all_mem[seg_num * SEG_LEN]);
}
Mem_list mem_alloc(Mem_list &free_list, int size)
{
    int n=size/SEG_LEN;
    if(size > n * SEG_LEN)
        ++n;
    Mem_seg *phead=free_list.head;
    Mem_seg *pend=free_list.head;
    for(int i =0;i        pend=pend->next;
    free_list.head=pend;
    return Mem_list(phead,pend);
}
int mem_free(Mem_list &free_list, Mem_list recycle_list)
{
    Mem_seg *ptemp=recycle_list.head;
    while(ptemp->next != recycle_list.end)
        ptemp=ptemp->next;
    ptemp->next=free_list.head;
    free_list.head=recycle_list.head;   
}
void test_list(Mem_list test_list)
{
    std::ofstream outfile;
    outfile.open("test.txt", std::ios::app);
    Mem_seg * phead = test_list.head;
    Mem_seg * pend = test_list.end;
    for(int i=0; phead != pend;phead=phead->next,i++)
        outfile<mem)<<",\t";
    outfile<    outfile.close();
}