CSE320/hw3/include/sfmm.h

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/**
* === DO NOT MODIFY THIS FILE ===
* If you need some other prototypes or constants in a header, please put them
* in another header file.
*
* When we grade, we will be replacing this file with our own copy.
* You have been warned.
* === DO NOT MODIFY THIS FILE ===
*/
#ifndef SFMM_H
#define SFMM_H
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
/*
Format of an allocated memory block
+-----------------------------------------------------------------------------------------+
| 64-bit-wide row |
+-----------------------------------------------------------------------------------------+
+----------------------------+----------------------+--------+--------+---------+---------+ <- header
| payload size | block_size | unused | alloc |prv alloc|in qklst |
| (0/1) |(4 LSB's implicitly 0)| (0) | (1) | (0/1) | (0) |
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+---------------------------------------------------+--------+--------+---------+---------+ <- (aligned)
| |
| Payload and Padding |
| (N rows) |
| |
| |
+-----------------------------------------------------------------------------------------+
NOTE: For an allocated block, there is no footer (it is used for payload).
NOTE: The actual stored header is obfuscated by bitwise XOR'ing with MAGIC.
The above diagram shows the un-obfuscated contents.
*/
/*
Format of a memory block in a quick list
+-----------------------------------------------------------------------------------------+
| 64-bit-wide row |
+-----------------------------------------------------------------------------------------+
+----------------------------+----------------------+--------+--------+---------+---------+ <- header
| unused | block_size | unused | alloc |prv alloc|in qklst |
| (0) |(4 LSB's implicitly 0)| (0) | (1) | (0/1) | (1) |
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+---------------------------------------------------+--------+--------+---------+---------+ <- (aligned)
| |
| Payload and Padding |
| (N rows) |
| |
| |
+-----------------------------------------------------------------------------------------+
NOTE: For a block in a quick list, there is no footer.
*/
/*
Format of a free memory block
+----------------------------+----------------------+--------+--------+---------+---------+ <- header
| unused | block_size | unused | alloc |prv alloc|in qklst |
| (0) |(4 LSB's implicitly 0)| (0) | (0) | (0/1) | (0) |
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+------------------------------------------------------------+--------+---------+---------+ <- (aligned)
| |
| Pointer to next free block |
| (1 row) |
+-----------------------------------------------------------------------------------------+
| |
| Pointer to previous free block |
| (1 row) |
+-----------------------------------------------------------------------------------------+
| |
| Unused |
| (N rows) |
| |
| |
+------------------------------------------------------------+--------+---------+---------+ <- footer
| unused | block_size | unused | alloc |prv alloc|in qklst |
| (0) |(4 LSB's implicitly 0)| (0) | (0) | (0/1) | (0) |
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+------------------------------------------------------------+--------+---------+---------+
NOTE: For a free block, footer contents must always be identical to header contents.
NOTE: The actual stored footer is obfuscated by bitwise XOR'ing with MAGIC.
The above diagram shows the un-obfuscated contents.
*/
#define IN_QUICK_LIST 0x1
#define PREV_BLOCK_ALLOCATED 0x2
#define THIS_BLOCK_ALLOCATED 0x4
typedef uint32_t sf_size_t;
typedef uint64_t sf_header;
typedef sf_header sf_footer;
/*
* Structure of a block.
* The first field of this structure is actually the footer of the *previous* block.
* This must be taken into account when creating sf_block pointers from memory addresses.
*/
typedef struct sf_block {
sf_footer prev_footer; // NOTE: This actually belongs to the *previous* block.
sf_header header; // This is where the current block really starts.
union {
/* A free block contains links to other blocks in a free list. */
struct {
struct sf_block *next;
struct sf_block *prev;
} links;
/* An allocated block contains a payload (aligned), starting here. */
char payload[0]; // Length varies according to block size.
} body;
} sf_block;
/*
* The heap is designed to keep the payload area of each block aligned to a two-row (16-byte)
* boundary. The header of a block precedes the payload area, and is only single-row (8-byte)
* aligned. The first block of the heap starts as soon as possible after the beginning of the
* heap, subject to the condition that its payload area is two-row aligned.
*/
/*
Format of the heap
+-----------------------------------------------------------------------------------------+
| 64-bit-wide row |
+-----------------------------------------------------------------------------------------+
+-----------------------------------------------------------------------------------------+ <- heap start
| | (aligned)
| Unused |
| (1 row) |
+----------------------------+----------------------+--------+--------+---------+---------+ <- header
| payload size |minimum block_size(32)| unused | alloc |prv alloc|in qklst |
| (0) |(4 LSB's implicitly 0)| (0) | (1) | (0/1) | (0) | prologue block
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+------------------------------------------------------------+--------+---------+---------+ <- (aligned)
| |
| Unused Payload Area |
| (3 rows) |
+------------------------------------------------------------+--------+---------+---------+ <- header
| payload size | block_size | unused | alloc |prv alloc|in qklst |
| (0/1) |(4 LSB's implicitly 0)| (0) | (0/1) | (0/1) | (0/1) | first block
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+------------------------------------------------------------+--------+---------+---------+ <- (aligned)
| |
| Payload and Padding |
| (N rows) |
| |
| |
+--------------------------------------------+------------------------+---------+---------+
| |
| |
| |
| |
| Additional allocated and free blocks |
| |
| |
| |
+-----------------------------------------------------------------------------------------+
| payload size | block_size | unused | alloc |prv alloc|in qklst |
| (0) | (0) | (0) | (1) | (0/1) | (0) | epilogue
| (32 bits) | (28 bits) | 1 bit | 1 bit | 1 bit | 1 bit |
+------------------------------------------------------------+--------+---------+---------+ <- heap_end
(aligned)
NOTE: The actual stored epilogue is obfuscated by bitwise XOR'ing with MAGIC.
The above diagram shows the un-obfuscated contents.
*/
/* sf_errno: will be set on error */
int sf_errno;
/*
* "Quick lists": These are used to hold recently freed blocks of small sizes, so that they
* can be used to satisfy allocations without searching lists or splitting blocks.
* Blocks on a quick list are marked as allocated, so they are not available for coalescing.
* The number of blocks in any individual quick list is limited to QUICK_LIST_MAX.
* If adding a block to a quick list would cause it to exceed QUICK_LIST_MAX, then the
* list is flushed, returning the existing blocks in the list to the main pool, and then
* the block being freed is added to the now-empty list, leaving that list containing one block.
*
* The quick lists are indexed by (size-MIN_BLOCK_SIZE)/ALIGN_SIZE, starting with blocks of the
* minimum block size at index 0, blocks of size MIN_BLOCK_SIZE+ALIGN_SIZE at index 1, and so on.
* They are maintained as singly linked lists, using a LIFO discipline.
*/
#define NUM_QUICK_LISTS 10 /* Number of quick lists. */
#define QUICK_LIST_MAX 5 /* Maximum number of blocks permitted on a single quick list. */
struct {
int length; // Number of blocks currently in the list.
struct sf_block *first; // Pointer to first block in the list.
} sf_quick_lists[NUM_QUICK_LISTS];
/*
* Free blocks are maintained in a set of circular, doubly linked lists, segregated by
* size class. The first list holds blocks of the minimum size M. The second list holds
* blocks of size (M, 2M]. The third list holds blocks whose size is in the interval (2M, 4M].
* The fourth list holds blocks whose size is in the interval (4M, 8M], and so on.
* This continues up to the interval (128M, 256M], and then the last list holds all blocks
* of size greater than 256M.
*
* Each of the circular, doubly linked lists has a "dummy" block used as the list header.
* This dummy block is always linked between the last and the first element of the list.
* In an empty list, the next and free pointers of the list header point back to itself.
* In a list with something in it, the next pointer of the header points to the first node
* in the list and the previous pointer of the header points to the last node in the list.
* The header itself is never removed from the list and it contains no data (only the link
* fields are used). The reason for doing things this way is to avoid edge cases in insertion
* and deletion of nodes from the list.
*/
#define NUM_FREE_LISTS 10
struct sf_block sf_free_list_heads[NUM_FREE_LISTS];
/*
* This is your implementation of sf_malloc. It acquires uninitialized memory that
* is aligned and padded properly for the underlying system.
*
* @param size The number of bytes requested to be allocated.
*
* @return If size is 0, then NULL is returned without setting sf_errno.
* If size is nonzero, then if the allocation is successful a pointer to a valid region of
* memory of the requested size is returned. If the allocation is not successful, then
* NULL is returned and sf_errno is set to ENOMEM.
*/
void *sf_malloc(sf_size_t size);
/*
* Resizes the memory pointed to by ptr to size bytes.
*
* @param ptr Address of the memory region to resize.
* @param size The minimum size to resize the memory to.
*
* @return If successful, the pointer to a valid region of memory is
* returned, else NULL is returned and sf_errno is set appropriately.
*
* If sf_realloc is called with an invalid pointer sf_errno should be set to EINVAL.
* If there is no memory available sf_realloc should set sf_errno to ENOMEM.
*
* If sf_realloc is called with a valid pointer and a size of 0 it should free
* the allocated block and return NULL without setting sf_errno.
*/
void *sf_realloc(void *ptr, sf_size_t size);
/*
* Marks a dynamically allocated region as no longer in use.
* Adds the newly freed block to the free list.
*
* @param ptr Address of memory returned by the function sf_malloc.
*
* If ptr is invalid, the function calls abort() to exit the program.
*/
void sf_free(void *ptr);
/*
* Get the current amount of internal fragmentation of the heap.
*
* @return the current amount of internal fragmentation, defined to be the
* ratio of the total amount of payload to the total size of allocated blocks.
* If there are no allocated blocks, then the returned value should be 0.0.
*/
double sf_internal_fragmentation();
/*
* Get the peak memory utilization for the heap.
*
* @return the peak memory utilization over the interval starting from the
* time the heap was initialized, up to the current time. The peak memory
* utilization at a given time, as defined in the lecture and textbook,
* is the ratio of the maximum aggregate payload up to that time, divided
* by the current heap size. If the heap has not yet been initialized,
* this function should return 0.0.
*/
double sf_peak_utilization();
/* sfutil.c: Helper functions already created for this assignment. */
/*
* @return The starting address of the heap for your allocator.
*/
void *sf_mem_start();
/*
* @return The ending address of the heap for your allocator.
*/
void *sf_mem_end();
/*
* This function increases the size of your heap by adding one page of
* memory to the end.
*
* @return On success, this function returns a pointer to the start of the
* additional page, which is the same as the value that would have been returned
* by get_heap_end() before the size increase. On error, NULL is returned.
*/
void *sf_mem_grow();
/* The size of a page of memory returned by sf_mem_grow(). */
#define PAGE_SZ ((sf_size_t)1024)
/*
* @return The "magic number" used to obfuscate header and footer contents
* to make it difficult to free a block without having first succesfully
* malloc'ed one.
*/
sf_header sf_magic();
2022-03-26 00:27:38 -04:00
#define MAGIC (sf_magic())
// #ifndef WEAK_MAGIC
// #define MAGIC (sf_magic())
// #else
// #define MAGIC ((sf_header)0x0)
// #endif
/*
* Set the "magic number" used to obfuscate header and footer contents.
* Setting the magic number to zero essentially turns off obfuscation, which will
* to make your life easier during debugging. This function will be replaced
* by a dummy version during grading, so be sure to test your code without calling
* this function.
*
* @param magic The value to set the magic number to. Setting to 0x0 disables
* obfuscation.
*/
void sf_set_magic(sf_header magic);
/*
* Display the contents of the heap in a human-readable form.
*/
void sf_show_block(sf_block *bp);
void sf_show_blocks();
void sf_show_free_list(int index);
void sf_show_free_lists();
void sf_show_quick_list(int index);
void sf_show_quick_lists();
void sf_show_heap();
#endif