SSM runtime memory management and allocation. More...
#include <assert.h>#include <ssm-internal.h>#include <ssm.h>#include <stdio.h>#include <stdlib.h>
Include dependency graph for ssm-mem.c:
Go to the source code of this file.
Data Structures | |
| union | block |
| (The beginning of) a block of memory. More... | |
| struct | mem_pool |
| A memory pool, which maintains a free list. More... | |
Macros | |
| #define | BLOCKS_PER_PAGE (SSM_MEM_PAGE_SIZE / sizeof(block_t)) |
| The number of blocks in each memory page. More... | |
| #define | UNINITIALIZED_FREE_BLOCK ((block_t *)0x0) |
| A "pointer" that points to the next contiguous block in memory. More... | |
| #define | END_OF_FREELIST ((block_t *)0x42) |
| Sentinel value indicating the end of the free list. More... | |
Typedefs | |
| typedef union block | block_t |
| (The beginning of) a block of memory. More... | |
Functions | |
| static size_t | find_pool_size (size_t size) |
| Find the memory pool for some arbitrary size. More... | |
| static block_t * | find_next_block (block_t *block, size_t pool_size) |
| void | ssm_mem_init (void *(*alloc_page_handler)(void), void *(*alloc_mem_handler)(size_t), void(*free_mem_handler)(void *, size_t)) |
| Initializes the underlying allocator system. More... | |
| void | ssm_mem_destroy (void(*free_page_handler)(void *)) |
| Tears down the underlying allocator system. More... | |
| void * | ssm_mem_alloc (size_t size) |
| Allocate a contiguous range of memory. More... | |
| void | ssm_mem_free (void *m, size_t size) |
| Deallocate memory allocated by ssm_mem_alloc(). More... | |
| ssm_value_t | ssm_new_time_int (ssm_time_t time) |
| Allocate a ssm_time on the heap. More... | |
| ssm_value_t | ssm_new_adt_int (uint8_t field_count, uint8_t tag) |
| Allocate a new ADT object on the heap. More... | |
| ssm_value_t | ssm_new_sv_int (ssm_value_t val) |
| Allocate an ssm_sv on the heap. More... | |
| ssm_value_t | ssm_new_closure_int (ssm_func_t f, uint8_t arg_cap) |
| Allocate a closure on the heap. More... | |
| ssm_value_t | ssm_new_array_int (uint16_t elems) |
| Allocate an array on the heap. More... | |
| ssm_value_t | ssm_new_blob_int (uint16_t size) |
| Allocate a blob on the heap. More... | |
| void | ssm_drop_final (ssm_value_t v) |
| Finalize and free a heap object. More... | |
| void | ssm_dups (size_t cnt, ssm_value_t *arr) |
| Call ssm_dup() on an array of values. More... | |
| void | ssm_drops (size_t cnt, ssm_value_t *arr) |
| Call ssm_drop() on an array of values. More... | |
| void | ssm_mem_statistics_collect (ssm_mem_statistics_t *stats) |
| Collect and return statistics about the heap. More... | |
Variables | |
| struct mem_pool | mem_pools [SSM_MEM_POOL_COUNT] |
| Memory pools from SSM_MEM_POOL_MIN to SSM_MEM_POOL_MAX. More... | |
| static void *(* | alloc_page )(void) |
| Page allocation handler, set by ssm_mem_init(). More... | |
| static void *(* | alloc_mem )(size_t size) |
| Large memory allocation handler, set by ssm_mem_init(). More... | |
| static void(* | free_mem )(void *mem, size_t size) |
| Large memory release handler, set by ssm_mem_init(). More... | |
| static size_t | num_pages_allocated = 0 |
| Tracks how many pages have been allocated by alloc_pool(). More... | |
| static size_t | live_objects = 0 |
| static size_t | pages_allocated [SSM_MEM_POOL_COUNT] = {0} |
| static size_t | objects_allocated = 0 |
| static size_t | objects_freed = 0 |
Detailed Description
SSM runtime memory management and allocation.
Definition in file ssm-mem.c.
Macro Definition Documentation
◆ BLOCKS_PER_PAGE
| #define BLOCKS_PER_PAGE (SSM_MEM_PAGE_SIZE / sizeof(block_t)) |
◆ UNINITIALIZED_FREE_BLOCK
| #define UNINITIALIZED_FREE_BLOCK ((block_t *)0x0) |
◆ END_OF_FREELIST
| #define END_OF_FREELIST ((block_t *)0x42) |
Typedef Documentation
◆ block_t
(The beginning of) a block of memory.
The size of each block varies depending on which memory pool it resides in. When a block is being used (allocated), block_buf effectively gives a pointer to the beginning that block that can be indexed into.
When a block is not being used, it is maintained in a free list. If it is not at the head of the free list, then it is pointed to by the free_list_next field of some other block_t, while its own free_list_next points to the next block in the free list. To avoid initializing the free_list_next fields of "fresh" blocks, when free_list_next is UNINITIALIZED_FREE_BLOCK, the next free block contiguously follows the current block in memory. The last free block points to END_OF_FREELIST.
Function Documentation
◆ find_pool_size()
|
inlinestatic |
Find the memory pool for some arbitrary size.
Tries to find the smallest memory pool that will fit a block of size. Returns SSM_MEM_POOL_COUNT if no such pool exists, i.e., if size is greater than SSM_MEM_POOL_MAX.
Since SSM_MEM_POOL_COUNT is a (small) compile-time constant, this linear search is effectively contant time.
- Parameters
-
size the block size whose memory pool we are looking for.
- Returns
- index to the memory pool, or SSM_MEM_POOL_COUNT otherwise.
◆ find_next_block()
Variable Documentation
◆ mem_pools
| struct mem_pool mem_pools[SSM_MEM_POOL_COUNT] |
Memory pools from SSM_MEM_POOL_MIN to SSM_MEM_POOL_MAX.
◆ alloc_page
|
static |
Page allocation handler, set by ssm_mem_init().
◆ alloc_mem
|
static |
Large memory allocation handler, set by ssm_mem_init().
◆ free_mem
|
static |
Large memory release handler, set by ssm_mem_init().
◆ num_pages_allocated
|
static |
◆ live_objects
◆ pages_allocated
|
static |
