Recode Malloc

My Own malloc with mmap and munmap

usage

make && make test && ./run.sh ./mallocTest

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Approach

First Step : functions

Function	description	usage for the project
mmap	map something into memory	mmap(NULL, sizeMmap, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0)
munmap	unmap something into memory	munmap(ptr, ptr->size)
getpagesize	memory page size (align zone in heap(ask in the subject))	TINY_HEAP_ALLOCATION_SIZE (4 * getpagesize())
getrlimit	get resource limits	getrlimit(RLIMIT_DATA, &rpl)

Second Step : tuto malloc epita

• Epita Tuto Malloc

Recode your own basic malloc (without zone) helped by epita tuto.

Please note, this tutorial is made with brk(), so you will have to adapt.

Despite this, it offers a solid foundation on which to rely to fully understand the basics of the project!

Third Step : Add zone

Zone shema:

As mentionned in the subject :

Each zone must contain at least 100 allocations.

It mean, every zone can contain an allocation of size n (you choose the one you like).

for example I did:

// TINY can contain 120 BLOCKS of 100 bits (4 * getpagesize() / 100 + struct s_block)
#define TINY_HEAP_ALLOCATION_SIZE (4 * getpagesize())
// SMALL can contain 100 BLOCKS of 2000 bits
#define SMALL_HEAP_ALLOCATION_SIZE (50 * getpagesize())

So in one zone i can:

for (int i = 0; i < 120; i ++)
	malloc(100);

And if I malloc again, A new zone will be created.

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sources

• Epita Tuto Malloc