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/*
* mm-naive.c - The fastest, least memory-efficient malloc package.
*
* In this naive approach, a block is allocated by simply incrementing
* the brk pointer. A block is pure payload. There are no headers or
* footers. Blocks are never coalesced or reused. Realloc is
* implemented directly using mm_malloc and mm_free.
*
* NOTE TO STUDENTS: Replace this header comment with your own header
* comment that gives a high level description of your solution.
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <print>
#include <unistd.h>
#include "util/mm-implicit.h"
#include "mm.h"
#include "memlib.h"
using namespace std;
void print_list();
/*********************************************************
* NOTE TO STUDENTS: Before you do anything else, please
* provide your team information in the following struct.
********************************************************/
team_t team = {
/* Team name */
"ov4.org",
/* First member's full name */
"_ov4",
/* First member's email address */
"ov4@ov4.org",
/* Second member's full name (leave blank if none) */
"",
/* Second member's email address (leave blank if none) */
""
};
/*
* mm_init - initialize the malloc package.
*/
int mm_init(void)
{
return 0;
}
void mm_quit(int code, int line)
{
loggerln("exit, line: {}", line);
exit(code);
}
/*
* mm_malloc - Allocate a block by incrementing the brk pointer.
* Always allocate a block whose size is a multiple of the alignment.
*/
void *mm_malloc(size_t size)
{
loggerln("---------- malloc ----------");
loggerln("argument: {}", size);
print_list();
size_t newsize = align(size + SIZE_T_SIZE);
loggerln("newsize: {}", newsize);
size_t p = (size_t)mem_heap_lo();
bool prev_alloc = true;
while (true)
{
//if (newsize == 4080) sleep(1);
size_t status = 0;
loggerln("offset: {}", (size_t)p-(size_t)mem_heap_lo());
// out of heap
if (p >= (size_t)mem_heap_hi())
{
// then increase heap
// and set current pos to be free
// so it can be alloc'd soon
loggerln("before: max addr {}", offset((size_t)mem_heap_hi()));
mem_sbrk(newsize);
loggerln("sbrk {}", newsize);
loggerln("max addr {}", offset((size_t)mem_heap_hi()));
set_size(status, newsize);
set_alloc(status, false);
set_prev_alloc(status, true); // TODO
*(size_t*)p = status;
}
status = *(size_t*)p;
if (is_alloc(status))
{
p += get_size(status);
prev_alloc = true;
continue;
}
prev_alloc = false;
if (get_size(status) < newsize)
{
next(p);
continue;
}
size_t oldsize = get_size(status);
set_size(status, newsize);
set_alloc(status, true);
set_prev_alloc(status, true); // TODO
*(size_t*)p = status;
void *ret = (void*)((char*)p + SIZE_T_SIZE);
// if we don't use all of free space
// split free block into 2 parts
if (oldsize > newsize)
{
size_t free_status = 0;
set_size(free_status, oldsize - newsize);
set_alloc(free_status, false);
set_prev_alloc(free_status, true);
size_t free_header_p = p+newsize;
*(size_t*)(free_header_p) = free_status;
sync_footer(free_header_p);
loggerln("split free: free begins {}", offset(free_header_p));
}
loggerln("return: {}" , (size_t)ret-(size_t)mem_heap_lo());
return ret;
}
}
/*
* mm_free - Freeing a block does nothing.
*/
void mm_free(void *ptr)
{
if (ptr == nullptr) return;
loggerln("---------- free ----------");
loggerln("argument: {}", (size_t)ptr-(size_t)mem_heap_lo());
print_list();
size_t header = (size_t)ptr-SIZE_T_SIZE;
size_t next_header = header + get_size(*(size_t*)header);
if (next_header > (size_t)mem_heap_hi()) next_header = 0;
loggerln("header: {}", offset(header));
loggerln("header size: {}", get_size(*(size_t*)header));
loggerln("next: {}", next_header != 0 ? offset(next_header) : 0);
// free current block
set_alloc(*(size_t*)header, false);
sync_footer(header);
// if next_header is free
if ((next_header != 0)
&& (!is_alloc(*(size_t*)next_header)))
{
size_t newsize = get_size(*(size_t*)header) + get_size(*(size_t*)next_header);
loggerln("next free: newsize {}", newsize);
set_size(*(size_t*)header, newsize);
sync_footer(header);
}
// if prev exists
// and is free
if (!is_prev_alloc(*(size_t*)header)
&& header != (size_t)mem_heap_lo())
{
loggerln("handling prev free");
size_t prev_footer = header - SIZE_T_SIZE;
size_t prev_header = header - get_size(*(size_t*)prev_footer);
loggerln("prev_footer: {}", offset(prev_footer));
loggerln("prev footer size: {}", get_size(*(size_t*)prev_footer));
loggerln("ok 0");
size_t newsize = get_size(*(size_t*)prev_header) + get_size(*(size_t*)header);
loggerln("ok1");
set_size(*(size_t*)prev_header, newsize);
loggerln("ok2");
sync_footer(prev_header);
}
}
/*
* mm_realloc - Implemented simply in terms of mm_malloc and mm_free
*/
void *mm_realloc(void *ptr, size_t size)
{
void *oldptr = ptr;
void *newptr;
size_t copySize;
newptr = mm_malloc(size);
if (newptr == NULL)
return NULL;
copySize = *(size_t *)((char *)oldptr - SIZE_T_SIZE);
if (size < copySize)
copySize = size;
memcpy(newptr, oldptr, copySize);
mm_free(oldptr);
return newptr;
}
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