blob: 71b6fa47cf34d79e18f12a4f6c1d39d7821066c2 [file] [log] [blame]
/*
* Copyright (c) 2008-2009 Travis Geiselbrecht
* Copyright (c) 2009 Corey Tabaka
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <debug.h>
#include <err.h>
#include <list.h>
#include <rand.h>
#include <string.h>
#include <kernel/thread.h>
#include <lib/heap.h>
#define LOCAL_TRACE 0
#define DEBUG_HEAP 0
#define ALLOC_FILL 0x99
#define FREE_FILL 0x77
#define PADDING_FILL 0x55
#define PADDING_SIZE 64
#define ROUNDUP(a, b) (((a) + ((b)-1)) & ~((b)-1))
#define HEAP_MAGIC 'HEAP'
#if WITH_STATIC_HEAP
#if !defined(HEAP_START) || !defined(HEAP_LEN)
#error WITH_STATIC_HEAP set but no HEAP_START or HEAP_LEN defined
#endif
#else
// end of the binary
extern int _end;
// end of memory
extern int _heap_end;
#define HEAP_START ((unsigned long)&_end)
#define HEAP_LEN ((size_t)_heap_end - (size_t)&_end)
#endif
struct free_heap_chunk {
struct list_node node;
size_t len;
};
struct heap {
void *base;
size_t len;
struct list_node free_list;
};
// heap static vars
static struct heap theheap;
// structure placed at the beginning every allocation
struct alloc_struct_begin {
unsigned int magic;
void *ptr;
size_t size;
#if DEBUG_HEAP
void *padding_start;
size_t padding_size;
#endif
};
static void dump_free_chunk(struct free_heap_chunk *chunk)
{
dprintf(INFO, "\t\tbase %p, end 0x%lx, len 0x%zx\n", chunk, (vaddr_t)chunk + chunk->len, chunk->len);
}
static void heap_dump(void)
{
dprintf(INFO, "Heap dump:\n");
dprintf(INFO, "\tbase %p, len 0x%zx\n", theheap.base, theheap.len);
dprintf(INFO, "\tfree list:\n");
struct free_heap_chunk *chunk;
list_for_every_entry(&theheap.free_list, chunk, struct free_heap_chunk, node) {
dump_free_chunk(chunk);
}
}
static void heap_test(void)
{
void *ptr[16];
ptr[0] = heap_alloc(8, 0);
ptr[1] = heap_alloc(32, 0);
ptr[2] = heap_alloc(7, 0);
ptr[3] = heap_alloc(0, 0);
ptr[4] = heap_alloc(98713, 0);
ptr[5] = heap_alloc(16, 0);
heap_free(ptr[5]);
heap_free(ptr[1]);
heap_free(ptr[3]);
heap_free(ptr[0]);
heap_free(ptr[4]);
heap_free(ptr[2]);
heap_dump();
int i;
for (i=0; i < 16; i++)
ptr[i] = 0;
for (i=0; i < 32768; i++) {
unsigned int index = (unsigned int)rand() % 16;
if ((i % (16*1024)) == 0)
printf("pass %d\n", i);
// printf("index 0x%x\n", index);
if (ptr[index]) {
// printf("freeing ptr[0x%x] = %p\n", index, ptr[index]);
heap_free(ptr[index]);
ptr[index] = 0;
}
unsigned int align = 1 << ((unsigned int)rand() % 8);
ptr[index] = heap_alloc((unsigned int)rand() % 32768, align);
// printf("ptr[0x%x] = %p, align 0x%x\n", index, ptr[index], align);
DEBUG_ASSERT(((addr_t)ptr[index] % align) == 0);
// heap_dump();
}
for (i=0; i < 16; i++) {
if (ptr[i])
heap_free(ptr[i]);
}
heap_dump();
}
// try to insert this free chunk into the free list, consuming the chunk by merging it with
// nearby ones if possible. Returns base of whatever chunk it became in the list.
static struct free_heap_chunk *heap_insert_free_chunk(struct free_heap_chunk *chunk)
{
#if DEBUGLEVEL > INFO
vaddr_t chunk_end = (vaddr_t)chunk + chunk->len;
#endif
// dprintf("%s: chunk ptr %p, size 0x%lx, chunk_end 0x%x\n", __FUNCTION__, chunk, chunk->len, chunk_end);
struct free_heap_chunk *next_chunk;
struct free_heap_chunk *last_chunk;
// walk through the list, finding the node to insert before
list_for_every_entry(&theheap.free_list, next_chunk, struct free_heap_chunk, node) {
if (chunk < next_chunk) {
DEBUG_ASSERT(chunk_end <= (vaddr_t)next_chunk);
list_add_before(&next_chunk->node, &chunk->node);
goto try_merge;
}
}
// walked off the end of the list, add it at the tail
list_add_tail(&theheap.free_list, &chunk->node);
// try to merge with the previous chunk
try_merge:
last_chunk = list_prev_type(&theheap.free_list, &chunk->node, struct free_heap_chunk, node);
if (last_chunk) {
if ((vaddr_t)last_chunk + last_chunk->len == (vaddr_t)chunk) {
// easy, just extend the previous chunk
last_chunk->len += chunk->len;
// remove ourself from the list
list_delete(&chunk->node);
// set the chunk pointer to the newly extended chunk, in case
// it needs to merge with the next chunk below
chunk = last_chunk;
}
}
// try to merge with the next chunk
if (next_chunk) {
if ((vaddr_t)chunk + chunk->len == (vaddr_t)next_chunk) {
// extend our chunk
chunk->len += next_chunk->len;
// remove them from the list
list_delete(&next_chunk->node);
}
}
return chunk;
}
struct free_heap_chunk *heap_create_free_chunk(void *ptr, size_t len)
{
DEBUG_ASSERT((len % sizeof(void *)) == 0); // size must be aligned on pointer boundary
#if DEBUG_HEAP
memset(ptr, FREE_FILL, len);
#endif
struct free_heap_chunk *chunk = (struct free_heap_chunk *)ptr;
chunk->len = len;
return chunk;
}
void *heap_alloc(size_t size, unsigned int alignment)
{
void *ptr;
#if DEBUG_HEAP
size_t original_size = size;
#endif
LTRACEF("size %zd, align %d\n", size, alignment);
// alignment must be power of 2
if (alignment & (alignment - 1))
return NULL;
// we always put a size field + base pointer + magic in front of the allocation
size += sizeof(struct alloc_struct_begin);
#if DEBUG_HEAP
size += PADDING_SIZE;
#endif
// make sure we allocate at least the size of a struct free_heap_chunk so that
// when we free it, we can create a struct free_heap_chunk struct and stick it
// in the spot
if (size < sizeof(struct free_heap_chunk))
size = sizeof(struct free_heap_chunk);
// round up size to a multiple of native pointer size
size = ROUNDUP(size, sizeof(void *));
// deal with nonzero alignments
if (alignment > 0) {
if (alignment < 16)
alignment = 16;
// add alignment for worst case fit
size += alignment;
}
// critical section
enter_critical_section();
// walk through the list
ptr = NULL;
struct free_heap_chunk *chunk;
list_for_every_entry(&theheap.free_list, chunk, struct free_heap_chunk, node) {
DEBUG_ASSERT((chunk->len % sizeof(void *)) == 0); // len should always be a multiple of pointer size
// is it big enough to service our allocation?
if (chunk->len >= size) {
ptr = chunk;
// remove it from the list
struct list_node *next_node = list_next(&theheap.free_list, &chunk->node);
list_delete(&chunk->node);
if (chunk->len > size + sizeof(struct free_heap_chunk)) {
// there's enough space in this chunk to create a new one after the allocation
struct free_heap_chunk *newchunk = heap_create_free_chunk((uint8_t *)ptr + size, chunk->len - size);
// truncate this chunk
chunk->len -= chunk->len - size;
// add the new one where chunk used to be
if (next_node)
list_add_before(next_node, &newchunk->node);
else
list_add_tail(&theheap.free_list, &newchunk->node);
}
// the allocated size is actually the length of this chunk, not the size requested
DEBUG_ASSERT(chunk->len >= size);
size = chunk->len;
#if DEBUG_HEAP
memset(ptr, ALLOC_FILL, size);
#endif
ptr = (void *)((addr_t)ptr + sizeof(struct alloc_struct_begin));
// align the output if requested
if (alignment > 0) {
ptr = (void *)ROUNDUP((addr_t)ptr, alignment);
}
struct alloc_struct_begin *as = (struct alloc_struct_begin *)ptr;
as--;
as->magic = HEAP_MAGIC;
as->ptr = (void *)chunk;
as->size = size;
#if DEBUG_HEAP
as->padding_start = ((uint8_t *)ptr + original_size);
as->padding_size = (((addr_t)chunk + size) - ((addr_t)ptr + original_size));
// printf("padding start %p, size %u, chunk %p, size %u\n", as->padding_start, as->padding_size, chunk, size);
memset(as->padding_start, PADDING_FILL, as->padding_size);
#endif
break;
}
}
LTRACEF("returning ptr %p\n", ptr);
// heap_dump();
exit_critical_section();
return ptr;
}
void *heap_realloc(void *ptr, size_t size)
{
void * tmp_ptr = NULL;
size_t min_size;
struct alloc_struct_begin *as = (struct alloc_struct_begin *)ptr;
as--;
if (size != 0){
tmp_ptr = heap_alloc(size, 0);
if (ptr != NULL && tmp_ptr != NULL){
min_size = (size < as->size) ? size : as->size;
memcpy(tmp_ptr, ptr, min_size);
heap_free(ptr);
}
} else {
if (ptr != NULL)
heap_free(ptr);
}
return(tmp_ptr);
}
void heap_free(void *ptr)
{
if (ptr == 0)
return;
LTRACEF("ptr %p\n", ptr);
// check for the old allocation structure
struct alloc_struct_begin *as = (struct alloc_struct_begin *)ptr;
as--;
DEBUG_ASSERT(as->magic == HEAP_MAGIC);
#if DEBUG_HEAP
{
uint i;
uint8_t *pad = (uint8_t *)as->padding_start;
for (i = 0; i < as->padding_size; i++) {
if (pad[i] != PADDING_FILL) {
printf("free at %p scribbled outside the lines:\n", ptr);
hexdump(pad, as->padding_size);
panic("die\n");
}
}
}
#endif
LTRACEF("allocation was %zd bytes long at ptr %p\n", as->size, as->ptr);
// looks good, create a free chunk and add it to the pool
enter_critical_section();
heap_insert_free_chunk(heap_create_free_chunk(as->ptr, as->size));
exit_critical_section();
// heap_dump();
}
void heap_init(void)
{
LTRACE_ENTRY;
// set the heap range
theheap.base = (void *)HEAP_START;
theheap.len = HEAP_LEN;
LTRACEF("base %p size %zd bytes\n", theheap.base, theheap.len);
// initialize the free list
list_initialize(&theheap.free_list);
// create an initial free chunk
heap_insert_free_chunk(heap_create_free_chunk(theheap.base, theheap.len));
// dump heap info
// heap_dump();
// dprintf(INFO, "running heap tests\n");
// heap_test();
}
#if DEBUGLEVEL > 1
#if WITH_LIB_CONSOLE
#include <lib/console.h>
static int cmd_heap(int argc, const cmd_args *argv);
STATIC_COMMAND_START
STATIC_COMMAND("heap", "heap debug commands", &cmd_heap)
STATIC_COMMAND_END(heap);
static int cmd_heap(int argc, const cmd_args *argv)
{
if (argc < 2) {
printf("not enough arguments\n");
return -1;
}
if (strcmp(argv[1].str, "info") == 0) {
heap_dump();
} else {
printf("unrecognized command\n");
return -1;
}
return 0;
}
#endif
#endif