操作系统大作业 分配连续的8M物理内存

ApplyMemory.cpp

//By Brickgao
#include <iostream>
#include <queue>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <ctype.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
using namespace std;

int main(){
	void *st;
	int tmp1, tmp2, page;
	page = getpagesize();
	printf("Start apply memory...\n");
	st = mmap(0, 8 * 1024 * 1024, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS,-1, 0);
	if(st == MAP_FAILED){
		cout << "Error!\n";
	}
	else{
		int maxn =  8 * 1024 * 1024 / page;
		printf("Successfully apply 8M of memory.\n");
		printf("Memory start from: 0X%X\n", st);
		printf("Memory clean from page(0 ~ %d):", maxn);
		cin >> tmp1;
		while(tmp1 < 0 || tmp1 > maxn){
			cout << "Error, try again!\n";
			cin >> tmp1;
		}
		int maxn2 = maxn - tmp1;
		printf("Clean page(0 ~ %d):", maxn2);
		cin >> tmp2;
		while(tmp2 < 0 || tmp2 > maxn2){
			cout << "Error, try again!\n";
			cin >> tmp2;
		}
		if(munmap(st + tmp1 * page, tmp2 * page) == 0){
			printf("Memory has been clean from 0X%X to 0X%X.\n", st + tmp1 * page, st + (tmp1 + tmp2) * page);
		}
		else{
			printf("Memory cleaner error\n");
		}
	}
    return 0;
}