micropython/py/gc.h
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

67 lines
2.2 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.
*/
#ifndef __MICROPY_INCLUDED_PY_GC_H__
#define __MICROPY_INCLUDED_PY_GC_H__
#include <stdint.h>
#include "py/mpconfig.h"
#include "py/misc.h"
void gc_init(void *start, void *end);
// These lock/unlock functions can be nested.
// They can be used to prevent the GC from allocating/freeing.
void gc_lock(void);
void gc_unlock(void);
bool gc_is_locked(void);
// A given port must implement gc_collect by using the other collect functions.
void gc_collect(void);
void gc_collect_start(void);
void gc_collect_root(void **ptrs, mp_uint_t len);
void gc_collect_end(void);
void *gc_alloc(mp_uint_t n_bytes, bool has_finaliser);
void gc_free(void *ptr);
mp_uint_t gc_nbytes(const void *ptr);
void *gc_realloc(void *ptr, mp_uint_t n_bytes, bool allow_move);
typedef struct _gc_info_t {
mp_uint_t total;
mp_uint_t used;
mp_uint_t free;
mp_uint_t num_1block;
mp_uint_t num_2block;
mp_uint_t max_block;
} gc_info_t;
void gc_info(gc_info_t *info);
void gc_dump_info(void);
void gc_dump_alloc_table(void);
#endif // __MICROPY_INCLUDED_PY_GC_H__