micropython/py/malloc.c
Damien George ade9a05236 py: Improve allocation policy of qstr data.
Previous to this patch all interned strings lived in their own malloc'd
chunk.  On average this wastes N/2 bytes per interned string, where N is
the number-of-bytes for a quanta of the memory allocator (16 bytes on 32
bit archs).

With this patch interned strings are concatenated into the same malloc'd
chunk when possible.  Such chunks are enlarged inplace when possible,
and shrunk to fit when a new chunk is needed.

RAM savings with this patch are highly varied, but should always show an
improvement (unless only 3 or 4 strings are interned).  New version
typically uses about 70% of previous memory for the qstr data, and can
lead to savings of around 10% of total memory footprint of a running
script.

Costs about 120 bytes code size on Thumb2 archs (depends on how many
calls to gc_realloc are made).
2015-07-14 22:56:32 +01:00

188 lines
6.2 KiB
C

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "py/mpconfig.h"
#include "py/misc.h"
#include "py/mpstate.h"
#if 0 // print debugging info
#define DEBUG_printf DEBUG_printf
#else // don't print debugging info
#define DEBUG_printf(...) (void)0
#endif
#if MICROPY_MEM_STATS
#define UPDATE_PEAK() { if (MP_STATE_MEM(current_bytes_allocated) > MP_STATE_MEM(peak_bytes_allocated)) MP_STATE_MEM(peak_bytes_allocated) = MP_STATE_MEM(current_bytes_allocated); }
#endif
#if MICROPY_ENABLE_GC
#include "py/gc.h"
// We redirect standard alloc functions to GC heap - just for the rest of
// this module. In the rest of micropython source, system malloc can be
// freely accessed - for interfacing with system and 3rd-party libs for
// example. On the other hand, some (e.g. bare-metal) ports may use GC
// heap as system heap, so, to avoid warnings, we do undef's first.
#undef malloc
#undef free
#undef realloc
#define malloc(b) gc_alloc((b), false)
#define malloc_with_finaliser(b) gc_alloc((b), true)
#define free gc_free
#define realloc(ptr, n) gc_realloc(ptr, n, true)
#define realloc_ext(ptr, n, mv) gc_realloc(ptr, n, mv)
#else
#define realloc_ext(ptr, n, mv) realloc(ptr, n)
#endif // MICROPY_ENABLE_GC
void *m_malloc(size_t num_bytes) {
void *ptr = malloc(num_bytes);
if (ptr == NULL && num_bytes != 0) {
return m_malloc_fail(num_bytes);
}
#if MICROPY_MEM_STATS
MP_STATE_MEM(total_bytes_allocated) += num_bytes;
MP_STATE_MEM(current_bytes_allocated) += num_bytes;
UPDATE_PEAK();
#endif
DEBUG_printf("malloc %d : %p\n", num_bytes, ptr);
return ptr;
}
void *m_malloc_maybe(size_t num_bytes) {
void *ptr = malloc(num_bytes);
#if MICROPY_MEM_STATS
MP_STATE_MEM(total_bytes_allocated) += num_bytes;
MP_STATE_MEM(current_bytes_allocated) += num_bytes;
UPDATE_PEAK();
#endif
DEBUG_printf("malloc %d : %p\n", num_bytes, ptr);
return ptr;
}
#if MICROPY_ENABLE_FINALISER
void *m_malloc_with_finaliser(size_t num_bytes) {
void *ptr = malloc_with_finaliser(num_bytes);
if (ptr == NULL && num_bytes != 0) {
return m_malloc_fail(num_bytes);
}
#if MICROPY_MEM_STATS
MP_STATE_MEM(total_bytes_allocated) += num_bytes;
MP_STATE_MEM(current_bytes_allocated) += num_bytes;
UPDATE_PEAK();
#endif
DEBUG_printf("malloc %d : %p\n", num_bytes, ptr);
return ptr;
}
#endif
void *m_malloc0(size_t num_bytes) {
void *ptr = m_malloc(num_bytes);
if (ptr == NULL && num_bytes != 0) {
return m_malloc_fail(num_bytes);
}
memset(ptr, 0, num_bytes);
return ptr;
}
#if MICROPY_MALLOC_USES_ALLOCATED_SIZE
void *m_realloc(void *ptr, size_t old_num_bytes, size_t new_num_bytes) {
#else
void *m_realloc(void *ptr, size_t new_num_bytes) {
#endif
void *new_ptr = realloc(ptr, new_num_bytes);
if (new_ptr == NULL && new_num_bytes != 0) {
return m_malloc_fail(new_num_bytes);
}
#if MICROPY_MEM_STATS
// At first thought, "Total bytes allocated" should only grow,
// after all, it's *total*. But consider for example 2K block
// shrunk to 1K and then grown to 2K again. It's still 2K
// allocated total. If we process only positive increments,
// we'll count 3K.
size_t diff = new_num_bytes - old_num_bytes;
MP_STATE_MEM(total_bytes_allocated) += diff;
MP_STATE_MEM(current_bytes_allocated) += diff;
UPDATE_PEAK();
#endif
DEBUG_printf("realloc %p, %d, %d : %p\n", ptr, old_num_bytes, new_num_bytes, new_ptr);
return new_ptr;
}
#if MICROPY_MALLOC_USES_ALLOCATED_SIZE
void *m_realloc_maybe(void *ptr, size_t old_num_bytes, size_t new_num_bytes, bool allow_move) {
#else
void *m_realloc_maybe(void *ptr, size_t new_num_bytes, bool allow_move) {
#endif
void *new_ptr = realloc_ext(ptr, new_num_bytes, allow_move);
#if MICROPY_MEM_STATS
// At first thought, "Total bytes allocated" should only grow,
// after all, it's *total*. But consider for example 2K block
// shrunk to 1K and then grown to 2K again. It's still 2K
// allocated total. If we process only positive increments,
// we'll count 3K.
// Also, don't count failed reallocs.
if (!(new_ptr == NULL && new_num_bytes != 0)) {
size_t diff = new_num_bytes - old_num_bytes;
MP_STATE_MEM(total_bytes_allocated) += diff;
MP_STATE_MEM(current_bytes_allocated) += diff;
UPDATE_PEAK();
}
#endif
DEBUG_printf("realloc %p, %d, %d : %p\n", ptr, old_num_bytes, new_num_bytes, new_ptr);
return new_ptr;
}
#if MICROPY_MALLOC_USES_ALLOCATED_SIZE
void m_free(void *ptr, size_t num_bytes) {
#else
void m_free(void *ptr) {
#endif
free(ptr);
#if MICROPY_MEM_STATS
MP_STATE_MEM(current_bytes_allocated) -= num_bytes;
#endif
DEBUG_printf("free %p, %d\n", ptr, num_bytes);
}
#if MICROPY_MEM_STATS
size_t m_get_total_bytes_allocated(void) {
return MP_STATE_MEM(total_bytes_allocated);
}
size_t m_get_current_bytes_allocated(void) {
return MP_STATE_MEM(current_bytes_allocated);
}
size_t m_get_peak_bytes_allocated(void) {
return MP_STATE_MEM(peak_bytes_allocated);
}
#endif