内存分配

观察brk和mmap
cat /proc/$pid/maps

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>

int main()
{
    char* p0 = sbrk(0);
    //*p0 = 65;

    malloc(1);
    char* p1 = sbrk(0);
    printf("%d %p %p\n",p1-p0,p1,p0);
    malloc(1);
    char* p2 = sbrk(0);
    printf("%d %p %p\n",p2-p0,p2,p0);


    //*(p0+1024*136-1) = 65;
    //*(p0+1024*136) = 65;

    char* s = malloc(1024*256);
    char* p3 = sbrk(0);
    printf("%d %p %p %p\n",p3-p0,p3,p0,s);
    // s[1024*260] = 65;
    s[1024*260-16-1] = 65;

    sleep(500);
    //s[1024*1024-1] = 65;
    //char* p4 = sbrk(0);
    //printf("%d %p %p\n",p4-p0,p4,p0);

}