148 lines
4.7 KiB
C
148 lines
4.7 KiB
C
/*
|
|
* Copyright (c) 2011, 2012, 2013, 2014, 2015, 2022 Jonas 'Sortie' Termansen.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* stdlib/malloc.c
|
|
* Allocates a chunk of memory from the dynamic memory heap.
|
|
*/
|
|
|
|
#include <errno.h>
|
|
#include <malloc.h>
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#if defined(HEAP_NO_ASSERT)
|
|
#define __heap_verify() ((void) 0)
|
|
#undef assert
|
|
#define assert(x) do { ((void) 0); } while ( 0 )
|
|
#endif
|
|
|
|
#if !defined(HEAP_GUARD_DEBUG)
|
|
|
|
#ifdef __TRACE_ALLOCATION_SITES
|
|
void* malloc_trace(struct __allocation_site* allocation_site,
|
|
size_t original_size)
|
|
#else
|
|
void* malloc(size_t original_size)
|
|
#endif
|
|
{
|
|
if ( !heap_size_has_bin(original_size) )
|
|
return errno = ENOMEM, (void*) NULL;
|
|
|
|
// Decide how big an allocation we would like to make.
|
|
size_t chunk_outer_size = sizeof(struct heap_chunk) +
|
|
sizeof(struct heap_chunk_post);
|
|
size_t chunk_inner_size = heap_align(original_size);
|
|
size_t chunk_size = chunk_outer_size + chunk_inner_size;
|
|
|
|
if ( !heap_size_has_bin(chunk_size) )
|
|
return errno = ENOMEM, (void*) NULL;
|
|
|
|
// Decide which bins are large enough for our allocation.
|
|
size_t smallest_desirable_bin = heap_bin_for_allocation(chunk_size);
|
|
size_t smallest_desirable_bin_size = heap_size_of_bin(smallest_desirable_bin);
|
|
size_t desirable_bins = ~0UL << smallest_desirable_bin;
|
|
|
|
__heap_lock();
|
|
__heap_verify();
|
|
|
|
// Determine whether there are any bins that we can use.
|
|
size_t usable_bins = desirable_bins & __heap_state.bin_filled_bitmap;
|
|
|
|
// If there are no usable bins, attempt to expand the current part of the
|
|
// heap or create a new part.
|
|
if ( !usable_bins && __heap_expand_current_part(smallest_desirable_bin_size) )
|
|
usable_bins = desirable_bins & __heap_state.bin_filled_bitmap;
|
|
|
|
// If we failed to expand the current part or make a new one - then we are
|
|
// officially out of memory until someone deallocates something.
|
|
if ( !usable_bins )
|
|
{
|
|
__heap_verify();
|
|
__heap_unlock();
|
|
return (void*) NULL;
|
|
}
|
|
|
|
// Pick the smallest of the usable bins.
|
|
size_t bin_index = heap_bsf(usable_bins);
|
|
|
|
// Pick the first element of this bins linked list. This is our allocation.
|
|
struct heap_chunk* result_chunk = __heap_state.bin[bin_index];
|
|
assert(result_chunk);
|
|
assert(HEAP_IS_POINTER_ALIGNED(result_chunk, result_chunk->chunk_size));
|
|
|
|
assert(chunk_size <= result_chunk->chunk_size);
|
|
|
|
// Mark our chosen chunk as used and remove it from its bin.
|
|
heap_remove_chunk(result_chunk);
|
|
|
|
// If our chunk is larger than what we really needed and it is possible to
|
|
// split the chunk into two, then we should split off a part of it and
|
|
// return it to the heap for further allocation.
|
|
if ( heap_can_split_chunk(result_chunk, chunk_size) )
|
|
heap_split_chunk(result_chunk, chunk_size);
|
|
|
|
#ifdef __TRACE_ALLOCATION_SITES
|
|
allocation_site->current_size += result_chunk->chunk_size;
|
|
allocation_site->allocations++;
|
|
result_chunk->chunk_magic = MAGIC_OF_ALLOCATION_SITE(allocation_site);
|
|
#endif
|
|
|
|
__heap_verify();
|
|
__heap_unlock();
|
|
|
|
// Return the inner data associated with the chunk to the caller.
|
|
return heap_chunk_to_data(result_chunk);
|
|
}
|
|
|
|
#else
|
|
|
|
#include <sys/mman.h>
|
|
|
|
#ifdef __is_sortix_libk
|
|
#include <libk.h>
|
|
#endif
|
|
|
|
void* malloc(size_t original_size)
|
|
{
|
|
if ( !original_size )
|
|
original_size = 1;
|
|
size_t size = -(-original_size & ~15UL);
|
|
size_t needed = 16 + size;
|
|
needed = HEAP_ALIGN_PAGEUP(needed);
|
|
size_t virtsize = needed + HEAP_PAGE_SIZE;
|
|
#ifdef __is_sortix_libk
|
|
void* from = libk_mmap(virtsize, PROT_KREAD | PROT_KWRITE);
|
|
#else
|
|
void* from = mmap(NULL, virtsize, PROT_READ | PROT_WRITE,
|
|
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
|
|
#endif
|
|
if ( from == MAP_FAILED )
|
|
return NULL;
|
|
void* guard = (char*) from + needed;
|
|
#ifdef __is_sortix_libk
|
|
libk_mprotect(guard, HEAP_PAGE_SIZE, PROT_NONE);
|
|
#else
|
|
if ( mprotect(guard, HEAP_PAGE_SIZE, PROT_NONE) < 0 )
|
|
return munmap(from, virtsize), (void*) NULL;
|
|
#endif
|
|
struct heap_alloc* addralloc_ptr = (struct heap_alloc*) from;
|
|
addralloc_ptr->from = (uintptr_t) from;
|
|
addralloc_ptr->size = virtsize;
|
|
size_t offset = needed - size;
|
|
return (void*) (addralloc_ptr->from + offset);
|
|
}
|
|
|
|
#endif
|