732 lines
24 KiB
C
732 lines
24 KiB
C
/* ----------------------------------------------------------------------------
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* umm_malloc.c - a memory allocator for embedded systems (microcontrollers)
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*
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* See LICENSE for copyright notice
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* See README.md for acknowledgements and description of internals
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* ----------------------------------------------------------------------------
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*
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* R.Hempel 2007-09-22 - Original
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* R.Hempel 2008-12-11 - Added MIT License biolerplate
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* - realloc() now looks to see if previous block is free
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* - made common operations functions
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* R.Hempel 2009-03-02 - Added macros to disable tasking
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* - Added function to dump heap and check for valid free
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* pointer
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* R.Hempel 2009-03-09 - Changed name to umm_malloc to avoid conflicts with
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* the mm_malloc() library functions
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* - Added some test code to assimilate a free block
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* with the very block if possible. Complicated and
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* not worth the grief.
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* D.Frank 2014-04-02 - Fixed heap configuration when UMM_TEST_MAIN is NOT set,
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* added user-dependent configuration file umm_malloc_cfg.h
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* R.Hempel 2016-12-04 - Add support for Unity test framework
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* - Reorganize source files to avoid redundant content
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* - Move integrity and poison checking to separate file
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* R.Hempel 2017-12-29 - Fix bug in realloc when requesting a new block that
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* results in OOM error - see Issue 11
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* R.Hempel 2019-09-07 - Separate the malloc() and free() functionality into
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* wrappers that use critical section protection macros
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* and static core functions that assume they are
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* running in a protected con text. Thanks @devyte
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* R.Hempel 2020-01-07 - Add support for Fragmentation metric - See Issue 14
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* R.Hempel 2020-01-12 - Use explicitly sized values from stdint.h - See Issue 15
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* R.Hempel 2020-01-20 - Move metric functions back to umm_info - See Issue 29
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* R.Hempel 2020-02-01 - Macro functions are uppercased - See Issue 34
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* R.Hempel 2020-06-20 - Support alternate body size - See Issue 42
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* R.Hempel 2021-05-02 - Support explicit memory umm_init_heap() - See Issue 53
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* ----------------------------------------------------------------------------
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <stddef.h>
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#include <string.h>
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#include "umm_malloc_cfg.h" // Override with umm_malloc_cfg_xxx.h
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#include "umm_malloc.h"
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/* Use the default DBGLOG_LEVEL and DBGLOG_FUNCTION */
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// #define DBGLOG_ENABLE
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#define DBGLOG_LEVEL 0
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#ifdef DBGLOG_ENABLE
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#include "dbglog/dbglog.h"
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#endif
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extern void *UMM_MALLOC_CFG_HEAP_ADDR;
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extern uint32_t UMM_MALLOC_CFG_HEAP_SIZE;
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/* ------------------------------------------------------------------------- */
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UMM_H_ATTPACKPRE typedef struct umm_ptr_t {
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uint16_t next;
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uint16_t prev;
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} UMM_H_ATTPACKSUF umm_ptr;
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UMM_H_ATTPACKPRE typedef struct umm_block_t {
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union {
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umm_ptr used;
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} header;
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union {
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umm_ptr free;
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uint8_t data[UMM_BLOCK_BODY_SIZE - sizeof(struct umm_ptr_t)];
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} body;
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} UMM_H_ATTPACKSUF umm_block;
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#define UMM_FREELIST_MASK ((uint16_t)(0x8000))
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#define UMM_BLOCKNO_MASK ((uint16_t)(0x7FFF))
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/* ------------------------------------------------------------------------- */
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struct umm_heap_config {
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umm_block *pheap;
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size_t heap_size;
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uint16_t numblocks;
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};
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struct umm_heap_config umm_heap_current;
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// struct umm_heap_config umm_heaps[UMM_NUM_HEAPS];
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#define UMM_HEAP (umm_heap_current.pheap)
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#define UMM_HEAPSIZE (umm_heap_current.heap_size)
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#define UMM_NUMBLOCKS (umm_heap_current.numblocks)
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#define UMM_BLOCKSIZE (sizeof(umm_block))
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#define UMM_BLOCK_LAST (UMM_NUMBLOCKS - 1)
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/* -------------------------------------------------------------------------
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* These macros evaluate to the address of the block and data respectively
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*/
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#define UMM_BLOCK(b) (UMM_HEAP[b])
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#define UMM_DATA(b) (UMM_BLOCK(b).body.data)
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/* -------------------------------------------------------------------------
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* These macros evaluate to the index of the block - NOT the address!!!
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*/
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#define UMM_NBLOCK(b) (UMM_BLOCK(b).header.used.next)
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#define UMM_PBLOCK(b) (UMM_BLOCK(b).header.used.prev)
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#define UMM_NFREE(b) (UMM_BLOCK(b).body.free.next)
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#define UMM_PFREE(b) (UMM_BLOCK(b).body.free.prev)
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/* -------------------------------------------------------------------------
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* There are additional files that may be included here - normally it's
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* not a good idea to include .c files but in this case it keeps the
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* main umm_malloc file clear and prevents issues with exposing internal
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* data structures to other programs.
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* -------------------------------------------------------------------------
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*/
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#include "umm_integrity.c"
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#include "umm_poison.c"
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#include "umm_info.c"
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/* ------------------------------------------------------------------------ */
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static uint16_t umm_blocks(size_t size) {
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/*
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* The calculation of the block size is not too difficult, but there are
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* a few little things that we need to be mindful of.
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*
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* When a block removed from the free list, the space used by the free
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* pointers is available for data. That's what the first calculation
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* of size is doing.
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*/
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if (size <= (sizeof(((umm_block *)0)->body))) {
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return 1;
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}
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/*
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* If it's for more than that, then we need to figure out the number of
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* additional whole blocks the size of an umm_block are required.
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*/
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size -= (1 + (sizeof(((umm_block *)0)->body)));
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return 2 + size / (UMM_BLOCKSIZE);
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}
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/* ------------------------------------------------------------------------ */
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/*
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* Split the block `c` into two blocks: `c` and `c + blocks`.
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*
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* - `new_freemask` should be `0` if `c + blocks` used, or `UMM_FREELIST_MASK`
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* otherwise.
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*
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* Note that free pointers are NOT modified by this function.
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*/
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static void umm_split_block(uint16_t c,
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uint16_t blocks,
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uint16_t new_freemask) {
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UMM_NBLOCK(c + blocks) = (UMM_NBLOCK(c) & UMM_BLOCKNO_MASK) | new_freemask;
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UMM_PBLOCK(c + blocks) = c;
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UMM_PBLOCK(UMM_NBLOCK(c) & UMM_BLOCKNO_MASK) = (c + blocks);
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UMM_NBLOCK(c) = (c + blocks);
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}
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/* ------------------------------------------------------------------------ */
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static void umm_disconnect_from_free_list(uint16_t c) {
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/* Disconnect this block from the FREE list */
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UMM_NFREE(UMM_PFREE(c)) = UMM_NFREE(c);
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UMM_PFREE(UMM_NFREE(c)) = UMM_PFREE(c);
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/* And clear the free block indicator */
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UMM_NBLOCK(c) &= (~UMM_FREELIST_MASK);
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}
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/* ------------------------------------------------------------------------
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* The umm_assimilate_up() function does not assume that UMM_NBLOCK(c)
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* has the UMM_FREELIST_MASK bit set. It only assimilates up if the
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* next block is free.
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*/
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static void umm_assimilate_up(uint16_t c) {
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if (UMM_NBLOCK(UMM_NBLOCK(c)) & UMM_FREELIST_MASK) {
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UMM_FRAGMENTATION_METRIC_REMOVE(UMM_NBLOCK(c));
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/*
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* The next block is a free block, so assimilate up and remove it from
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* the free list
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*/
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DBGLOG_DEBUG("Assimilate up to next block, which is FREE\n");
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/* Disconnect the next block from the FREE list */
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umm_disconnect_from_free_list(UMM_NBLOCK(c));
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/* Assimilate the next block with this one */
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UMM_PBLOCK(UMM_NBLOCK(UMM_NBLOCK(c)) & UMM_BLOCKNO_MASK) = c;
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UMM_NBLOCK(c) = UMM_NBLOCK(UMM_NBLOCK(c)) & UMM_BLOCKNO_MASK;
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}
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}
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/* ------------------------------------------------------------------------
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* The umm_assimilate_down() function assumes that UMM_NBLOCK(c) does NOT
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* have the UMM_FREELIST_MASK bit set. In other words, try to assimilate
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* up before assimilating down.
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*/
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static uint16_t umm_assimilate_down(uint16_t c, uint16_t freemask) {
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// We are going to assimilate down to the previous block because
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// it was free, so remove it from the fragmentation metric
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UMM_FRAGMENTATION_METRIC_REMOVE(UMM_PBLOCK(c));
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UMM_NBLOCK(UMM_PBLOCK(c)) = UMM_NBLOCK(c) | freemask;
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UMM_PBLOCK(UMM_NBLOCK(c)) = UMM_PBLOCK(c);
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if (freemask) {
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// We are going to free the entire assimilated block
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// so add it to the fragmentation metric. A good
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// compiler will optimize away the empty if statement
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// when UMM_INFO is not defined, so don't worry about
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// guarding it.
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UMM_FRAGMENTATION_METRIC_ADD(UMM_PBLOCK(c));
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}
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return UMM_PBLOCK(c);
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}
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/* ------------------------------------------------------------------------- */
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void umm_init_heap(void *ptr, size_t size)
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{
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/* init heap pointer and size, and memset it to 0 */
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UMM_HEAP = (umm_block *)ptr;
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UMM_HEAPSIZE = size;
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UMM_NUMBLOCKS = (UMM_HEAPSIZE / UMM_BLOCKSIZE);
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memset(UMM_HEAP, 0x00, UMM_HEAPSIZE);
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/* setup initial blank heap structure */
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UMM_FRAGMENTATION_METRIC_INIT();
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/* Set up umm_block[0], which just points to umm_block[1] */
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UMM_NBLOCK(0) = 1;
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UMM_NFREE(0) = 1;
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UMM_PFREE(0) = 1;
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/*
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* Now, we need to set the whole heap space as a huge free block. We should
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* not touch umm_block[0], since it's special: umm_block[0] is the head of
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* the free block list. It's a part of the heap invariant.
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*
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* See the detailed explanation at the beginning of the file.
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*
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* umm_block[1] has pointers:
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*
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* - next `umm_block`: the last one umm_block[n]
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* - prev `umm_block`: umm_block[0]
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*
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* Plus, it's a free `umm_block`, so we need to apply `UMM_FREELIST_MASK`
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*
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* And it's the last free block, so the next free block is 0 which marks
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* the end of the list. The previous block and free block pointer are 0
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* too, there is no need to initialize these values due to the init code
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* that memsets the entire umm_ space to 0.
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*/
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UMM_NBLOCK(1) = UMM_BLOCK_LAST | UMM_FREELIST_MASK;
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/*
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* Last umm_block[n] has the next block index at 0, meaning it's
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* the end of the list, and the previous block is umm_block[1].
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*
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* The last block is a special block and can never be part of the
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* free list, so its pointers are left at 0 too.
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*/
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UMM_PBLOCK(UMM_BLOCK_LAST) = 1;
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// DBGLOG_FORCE(true, "nblock(0) %04x pblock(0) %04x nfree(0) %04x pfree(0) %04x\n", UMM_NBLOCK(0) & UMM_BLOCKNO_MASK, UMM_PBLOCK(0), UMM_NFREE(0), UMM_PFREE(0));
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// DBGLOG_FORCE(true, "nblock(1) %04x pblock(1) %04x nfree(1) %04x pfree(1) %04x\n", UMM_NBLOCK(1) & UMM_BLOCKNO_MASK, UMM_PBLOCK(1), UMM_NFREE(1), UMM_PFREE(1));
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}
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void umm_init(void) {
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/* Initialize the heap from linker supplied values */
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umm_init_heap(UMM_MALLOC_CFG_HEAP_ADDR, UMM_MALLOC_CFG_HEAP_SIZE);
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}
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/* ------------------------------------------------------------------------
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* Must be called only from within critical sections guarded by
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* UMM_CRITICAL_ENTRY() and UMM_CRITICAL_EXIT().
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*/
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static void umm_free_core(void *ptr) {
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uint16_t c;
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/*
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* FIXME: At some point it might be a good idea to add a check to make sure
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* that the pointer we're being asked to free up is actually within
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* the umm_heap!
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*
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* NOTE: See the new umm_info() function that you can use to see if a ptr is
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* on the free list!
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*/
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/* Figure out which block we're in. Note the use of truncated division... */
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c = (((uint8_t *)ptr) - (uint8_t *)(&(UMM_HEAP[0]))) / UMM_BLOCKSIZE;
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DBGLOG_DEBUG("Freeing block %6i\n", c);
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/* Now let's assimilate this block with the next one if possible. */
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umm_assimilate_up(c);
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/* Then assimilate with the previous block if possible */
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if (UMM_NBLOCK(UMM_PBLOCK(c)) & UMM_FREELIST_MASK) {
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DBGLOG_DEBUG("Assimilate down to previous block, which is FREE\n");
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c = umm_assimilate_down(c, UMM_FREELIST_MASK);
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} else {
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/*
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* The previous block is not a free block, so add this one to the head
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* of the free list
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*/
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UMM_FRAGMENTATION_METRIC_ADD(c);
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DBGLOG_DEBUG("Just add to head of free list\n");
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UMM_PFREE(UMM_NFREE(0)) = c;
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UMM_NFREE(c) = UMM_NFREE(0);
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UMM_PFREE(c) = 0;
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UMM_NFREE(0) = c;
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UMM_NBLOCK(c) |= UMM_FREELIST_MASK;
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}
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}
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/* ------------------------------------------------------------------------ */
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void umm_free(void *ptr) {
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UMM_CHECK_INITIALIZED();
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/* If we're being asked to free a NULL pointer, well that's just silly! */
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if ((void *)0 == ptr) {
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DBGLOG_DEBUG("free a null pointer -> do nothing\n");
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return;
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}
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/* Free the memory withing a protected critical section */
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UMM_CRITICAL_ENTRY();
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umm_free_core(ptr);
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UMM_CRITICAL_EXIT();
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}
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/* ------------------------------------------------------------------------
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* Must be called only from within critical sections guarded by
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* UMM_CRITICAL_ENTRY() and UMM_CRITICAL_EXIT().
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*/
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static void *umm_malloc_core(size_t size) {
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uint16_t blocks;
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uint16_t blockSize = 0;
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uint16_t bestSize;
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uint16_t bestBlock;
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uint16_t cf;
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blocks = umm_blocks(size);
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/*
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* Now we can scan through the free list until we find a space that's big
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* enough to hold the number of blocks we need.
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*
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* This part may be customized to be a best-fit, worst-fit, or first-fit
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* algorithm
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*/
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cf = UMM_NFREE(0);
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bestBlock = UMM_NFREE(0);
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bestSize = 0x7FFF;
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while (cf) {
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blockSize = (UMM_NBLOCK(cf) & UMM_BLOCKNO_MASK) - cf;
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DBGLOG_TRACE("Looking at block %6i size %6i\n", cf, blockSize);
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#if defined UMM_BEST_FIT
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if ((blockSize >= blocks) && (blockSize < bestSize)) {
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bestBlock = cf;
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bestSize = blockSize;
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}
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#elif defined UMM_FIRST_FIT
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/* This is the first block that fits! */
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if ((blockSize >= blocks)) {
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break;
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}
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#else
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#error "No UMM_*_FIT is defined - check umm_malloc_cfg.h"
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#endif
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cf = UMM_NFREE(cf);
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}
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if (0x7FFF != bestSize) {
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cf = bestBlock;
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blockSize = bestSize;
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}
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if (UMM_NBLOCK(cf) & UMM_BLOCKNO_MASK && blockSize >= blocks) {
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UMM_FRAGMENTATION_METRIC_REMOVE(cf);
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/*
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* This is an existing block in the memory heap, we just need to split off
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* what we need, unlink it from the free list and mark it as in use, and
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* link the rest of the block back into the freelist as if it was a new
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* block on the free list...
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*/
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if (blockSize == blocks) {
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/* It's an exact fit and we don't neet to split off a block. */
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DBGLOG_DEBUG("Allocating %6i blocks starting at %6i - exact\n", blocks, cf);
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/* Disconnect this block from the FREE list */
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umm_disconnect_from_free_list(cf);
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} else {
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/* It's not an exact fit and we need to split off a block. */
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DBGLOG_DEBUG("Allocating %6i blocks starting at %6i - existing\n", blocks, cf);
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/*
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* split current free block `cf` into two blocks. The first one will be
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* returned to user, so it's not free, and the second one will be free.
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*/
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umm_split_block(cf, blocks, UMM_FREELIST_MASK /*new block is free*/);
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UMM_FRAGMENTATION_METRIC_ADD(UMM_NBLOCK(cf));
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/*
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* `umm_split_block()` does not update the free pointers (it affects
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* only free flags), but effectively we've just moved beginning of the
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* free block from `cf` to `cf + blocks`. So we have to adjust pointers
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* to and from adjacent free blocks.
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*/
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/* previous free block */
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UMM_NFREE(UMM_PFREE(cf)) = cf + blocks;
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UMM_PFREE(cf + blocks) = UMM_PFREE(cf);
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/* next free block */
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UMM_PFREE(UMM_NFREE(cf)) = cf + blocks;
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UMM_NFREE(cf + blocks) = UMM_NFREE(cf);
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}
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} else {
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/* Out of memory */
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DBGLOG_DEBUG("Can't allocate %5i blocks\n", blocks);
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return (void *)NULL;
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}
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return (void *)&UMM_DATA(cf);
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}
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/* ------------------------------------------------------------------------ */
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void *umm_malloc(size_t size) {
|
|
|
|
void *ptr = NULL;
|
|
|
|
UMM_CHECK_INITIALIZED();
|
|
|
|
/*
|
|
* the very first thing we do is figure out if we're being asked to allocate
|
|
* a size of 0 - and if we are we'll simply return a null pointer. if not
|
|
* then reduce the size by 1 byte so that the subsequent calculations on
|
|
* the number of blocks to allocate are easier...
|
|
*/
|
|
|
|
if (0 == size) {
|
|
DBGLOG_DEBUG("malloc a block of 0 bytes -> do nothing\n");
|
|
|
|
return ptr;
|
|
}
|
|
|
|
/* Allocate the memory withing a protected critical section */
|
|
|
|
UMM_CRITICAL_ENTRY();
|
|
|
|
ptr = umm_malloc_core(size);
|
|
|
|
UMM_CRITICAL_EXIT();
|
|
|
|
return ptr;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
void *umm_realloc(void *ptr, size_t size) {
|
|
|
|
uint16_t blocks;
|
|
uint16_t blockSize;
|
|
uint16_t prevBlockSize = 0;
|
|
uint16_t nextBlockSize = 0;
|
|
|
|
uint16_t c;
|
|
|
|
size_t curSize;
|
|
|
|
UMM_CHECK_INITIALIZED();
|
|
|
|
/*
|
|
* This code looks after the case of a NULL value for ptr. The ANSI C
|
|
* standard says that if ptr is NULL and size is non-zero, then we've
|
|
* got to work the same a malloc(). If size is also 0, then our version
|
|
* of malloc() returns a NULL pointer, which is OK as far as the ANSI C
|
|
* standard is concerned.
|
|
*/
|
|
|
|
if (((void *)NULL == ptr)) {
|
|
DBGLOG_DEBUG("realloc the NULL pointer - call malloc()\n");
|
|
|
|
return umm_malloc(size);
|
|
}
|
|
|
|
/*
|
|
* Now we're sure that we have a non_NULL ptr, but we're not sure what
|
|
* we should do with it. If the size is 0, then the ANSI C standard says that
|
|
* we should operate the same as free.
|
|
*/
|
|
|
|
if (0 == size) {
|
|
DBGLOG_DEBUG("realloc to 0 size, just free the block\n");
|
|
|
|
umm_free(ptr);
|
|
|
|
return (void *)NULL;
|
|
}
|
|
|
|
/*
|
|
* Otherwise we need to actually do a reallocation. A naiive approach
|
|
* would be to malloc() a new block of the correct size, copy the old data
|
|
* to the new block, and then free the old block.
|
|
*
|
|
* While this will work, we end up doing a lot of possibly unnecessary
|
|
* copying. So first, let's figure out how many blocks we'll need.
|
|
*/
|
|
|
|
blocks = umm_blocks(size);
|
|
|
|
/* Figure out which block we're in. Note the use of truncated division... */
|
|
|
|
c = (((uint8_t *)ptr) - (uint8_t *)(&(UMM_HEAP[0]))) / UMM_BLOCKSIZE;
|
|
|
|
/* Figure out how big this block is ... the free bit is not set :-) */
|
|
|
|
blockSize = (UMM_NBLOCK(c) - c);
|
|
|
|
/* Figure out how many bytes are in this block */
|
|
|
|
curSize = (blockSize * UMM_BLOCKSIZE) - (sizeof(((umm_block *)0)->header));
|
|
|
|
/* Protect the critical section... */
|
|
UMM_CRITICAL_ENTRY();
|
|
|
|
/* Now figure out if the previous and/or next blocks are free as well as
|
|
* their sizes - this will help us to minimize special code later when we
|
|
* decide if it's possible to use the adjacent blocks.
|
|
*
|
|
* We set prevBlockSize and nextBlockSize to non-zero values ONLY if they
|
|
* are free!
|
|
*/
|
|
|
|
if ((UMM_NBLOCK(UMM_NBLOCK(c)) & UMM_FREELIST_MASK)) {
|
|
nextBlockSize = (UMM_NBLOCK(UMM_NBLOCK(c)) & UMM_BLOCKNO_MASK) - UMM_NBLOCK(c);
|
|
}
|
|
|
|
if ((UMM_NBLOCK(UMM_PBLOCK(c)) & UMM_FREELIST_MASK)) {
|
|
prevBlockSize = (c - UMM_PBLOCK(c));
|
|
}
|
|
|
|
DBGLOG_DEBUG("realloc blocks %i blockSize %i nextBlockSize %i prevBlockSize %i\n", blocks, blockSize, nextBlockSize, prevBlockSize);
|
|
|
|
/*
|
|
* Ok, now that we're here we know how many blocks we want and the current
|
|
* blockSize. The prevBlockSize and nextBlockSize are set and we can figure
|
|
* out the best strategy for the new allocation as follows:
|
|
*
|
|
* 1. If the new block is the same size or smaller than the current block do
|
|
* nothing.
|
|
* 2. If the next block is free and adding it to the current block gives us
|
|
* EXACTLY enough memory, assimilate the next block. This avoids unwanted
|
|
* fragmentation of free memory.
|
|
*
|
|
* The following cases may be better handled with memory copies to reduce
|
|
* fragmentation
|
|
*
|
|
* 3. If the previous block is NOT free and the next block is free and
|
|
* adding it to the current block gives us enough memory, assimilate
|
|
* the next block. This may introduce a bit of fragmentation.
|
|
* 4. If the prev block is free and adding it to the current block gives us
|
|
* enough memory, remove the previous block from the free list, assimilate
|
|
* it, copy to the new block.
|
|
* 5. If the prev and next blocks are free and adding them to the current
|
|
* block gives us enough memory, assimilate the next block, remove the
|
|
* previous block from the free list, assimilate it, copy to the new block.
|
|
* 6. Otherwise try to allocate an entirely new block of memory. If the
|
|
* allocation works free the old block and return the new pointer. If
|
|
* the allocation fails, return NULL and leave the old block intact.
|
|
*
|
|
* TODO: Add some conditional code to optimise for less fragmentation
|
|
* by simply allocating new memory if we need to copy anyways.
|
|
*
|
|
* All that's left to do is decide if the fit was exact or not. If the fit
|
|
* was not exact, then split the memory block so that we use only the requested
|
|
* number of blocks and add what's left to the free list.
|
|
*/
|
|
|
|
// Case 1 - block is same size or smaller
|
|
if (blockSize >= blocks) {
|
|
DBGLOG_DEBUG("realloc the same or smaller size block - %i, do nothing\n", blocks);
|
|
/* This space intentionally left blank */
|
|
|
|
// Case 2 - block + next block fits EXACTLY
|
|
} else if ((blockSize + nextBlockSize) == blocks) {
|
|
DBGLOG_DEBUG("exact realloc using next block - %i\n", blocks);
|
|
umm_assimilate_up(c);
|
|
blockSize += nextBlockSize;
|
|
|
|
// Case 3 - prev block NOT free and block + next block fits
|
|
} else if ((0 == prevBlockSize) && (blockSize + nextBlockSize) >= blocks) {
|
|
DBGLOG_DEBUG("realloc using next block - %i\n", blocks);
|
|
umm_assimilate_up(c);
|
|
blockSize += nextBlockSize;
|
|
|
|
// Case 4 - prev block + block fits
|
|
} else if ((prevBlockSize + blockSize) >= blocks) {
|
|
DBGLOG_DEBUG("realloc using prev block - %i\n", blocks);
|
|
umm_disconnect_from_free_list(UMM_PBLOCK(c));
|
|
c = umm_assimilate_down(c, 0);
|
|
memmove((void *)&UMM_DATA(c), ptr, curSize);
|
|
ptr = (void *)&UMM_DATA(c);
|
|
blockSize += prevBlockSize;
|
|
|
|
// Case 5 - prev block + block + next block fits
|
|
} else if ((prevBlockSize + blockSize + nextBlockSize) >= blocks) {
|
|
DBGLOG_DEBUG("realloc using prev and next block - %i\n", blocks);
|
|
umm_assimilate_up(c);
|
|
umm_disconnect_from_free_list(UMM_PBLOCK(c));
|
|
c = umm_assimilate_down(c, 0);
|
|
memmove((void *)&UMM_DATA(c), ptr, curSize);
|
|
ptr = (void *)&UMM_DATA(c);
|
|
blockSize += (prevBlockSize + nextBlockSize);
|
|
|
|
// Case 6 - default is we need to realloc a new block
|
|
} else {
|
|
DBGLOG_DEBUG("realloc a completely new block %i\n", blocks);
|
|
void *oldptr = ptr;
|
|
if ((ptr = umm_malloc_core(size))) {
|
|
DBGLOG_DEBUG("realloc %i to a bigger block %i, copy, and free the old\n", blockSize, blocks);
|
|
memcpy(ptr, oldptr, curSize);
|
|
umm_free_core(oldptr);
|
|
} else {
|
|
DBGLOG_DEBUG("realloc %i to a bigger block %i failed - return NULL and leave the old block!\n", blockSize, blocks);
|
|
/* This space intentionally left blnk */
|
|
}
|
|
blockSize = blocks;
|
|
}
|
|
|
|
/* Now all we need to do is figure out if the block fit exactly or if we
|
|
* need to split and free ...
|
|
*/
|
|
|
|
if (blockSize > blocks) {
|
|
DBGLOG_DEBUG("split and free %i blocks from %i\n", blocks, blockSize);
|
|
umm_split_block(c, blocks, 0);
|
|
umm_free_core((void *)&UMM_DATA(c + blocks));
|
|
}
|
|
|
|
/* Release the critical section... */
|
|
UMM_CRITICAL_EXIT();
|
|
|
|
return ptr;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
void *umm_calloc(size_t num, size_t item_size) {
|
|
void *ret;
|
|
|
|
ret = umm_malloc((size_t)(item_size * num));
|
|
|
|
if (ret) {
|
|
memset(ret, 0x00, (size_t)(item_size * num));
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|