MyHeap

Deadline: September 28th, 2014

1 Instructions

Implement your own version of C's malloc, realloc and free using only mmap and munmap.

Function	Description
`my_malloc(x)`	Allocate `x` bytes of memory and returns a pointer to the allocated memory. Return 0 if no memory could be allocated. The return address must be sufficiently aligned for C's `long` and `void*` data types.
`my_free(p)`	Deallocate the allocation pointed to by `p`, or do nothing if `p` is 0.
`my_realloc(p, n)`	Reallocate the memory pointed to by `p` to fit `n` bytes of memory instead. Return a pointer to the reallocated memory, or 0 if the reallocation failed.

each function must be implemented in a .c file of its own, named after the function it contains. The function prototypes must be declared in a .h file, in accordance with the C coding standard. The submitted archive may (but needs not) include a test program. You must include a Makefile which properly places the functions in libminic.a.
you may assume a page size of 8192 bytes.
the only standard/system header you may include are <stddef.h> and <sys/mman.h>; the only external functions you may use are mmap and munmap (you may use functions from a previous assignment, by including their source in your submission).

6 points if my_malloc/my_free/my_realloc work as described. Tip: correctness > performance.
+1 point if the implementation makes a best effort to fit multiple small objects in a page.
+0.5 point if my_malloc attempts to reuse memory that was most recently freed.
+1 point if the implementation makes a best effort at releasing pages to the operating system.
+0.5 point if the implementation determines the page size automatically (using a portable mixture of getpagesize and sysconf; for this extra grade you may include <unistd.h>).
+1 point if the implementation provides its own wrappers for system calls.