[C++知识库]自定义方法统计堆内存峰值以及检测内存泄漏

?自定义malloc和free函数代替系统函数

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
static int total = 0;
static int mem_max = 0;

void* __real_malloc(size_t size);
void __real_free(void *ptr);

malloc函数：

void* __wrap_malloc(size_t size)
{
	if(size == 0){
		printf("malloc size = 0 error \n");
		return NULL;
	}
	char* ptr = __real_malloc(size + 4);
	total += size;
	*(int*)ptr = size;
	ptr += 4;
	if(mem_max < total)
		mem_max = total;
	return (void *)ptr;
}

free函数：

void __wrap_free(void *ptr)
{
	if(!ptr){
		printf("free NULL \n");
		return;
	}
	char * realaddr = ptr;
	int size = 0;
	realaddr -= 4;
	size = *((int*)realaddr);
	total -= size;
	__real_free(realaddr);
}

在代码流程中调用以下两个函数，打印当前内存消耗情况

int get_toal_mem()
{
	printf("mem current used %d, mem peak %d\n",total,mem_max);
	return total;
}


void print_mem_change(int mem_before)
{
	if(mem_before > total){
		printf("mem dec = %d##############\n",mem_before - total);
	}else if(total > mem_before ){
		printf("mem inc = %d##############\n",total - mem_before);
	}else{
		printf("mem not change@@@@@@@@@@@@@\n");
	}
	printf("mem before %d, mem current %d ------- mem_peak %d\n",mem_before,total,mem_max);
}