circuitpython/py/gc.h
Angus Gratton 519c24dd48 py/gc: Add new MICROPY_GC_SPLIT_HEAP_AUTO "auto grow heap" mode.
When set, the split heap is automatically extended with new areas on
demand, and shrunk if a heap area becomes empty during a GC pass or soft
reset.

To save code size the size allocation for a new heap block (including
metadata) is estimated at 103% of the failed allocation, rather than
working from the more complex algorithm in gc_try_add_heap(). This appears
to work well except in the extreme limit case when almost all RAM is
exhausted (~last few hundred bytes). However in this case some allocation
is likely to fail soon anyhow.

Currently there is no API to manually add a block of a given size to the
heap, although that could easily be added if necessary.

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <angus@redyak.com.au>
2023-08-15 10:48:02 +10:00

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2.8 KiB
C

/*
* This file is part of the MicroPython 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 <stdbool.h>
#include <stddef.h>
#include "py/mpprint.h"
void gc_init(void *start, void *end);
#if MICROPY_GC_SPLIT_HEAP
// Used to add additional memory areas to the heap.
void gc_add(void *start, void *end);
#if MICROPY_GC_SPLIT_HEAP_AUTO
// Port must implement this function to return the maximum available block of
// RAM to allocate a new heap area into using MP_PLAT_ALLOC_HEAP.
size_t gc_get_max_new_split(void);
#endif // MICROPY_GC_SPLIT_HEAP_AUTO
#endif // MICROPY_GC_SPLIT_HEAP
// 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, size_t len);
void gc_collect_end(void);
// Use this function to sweep the whole heap and run all finalisers
void gc_sweep_all(void);
enum {
GC_ALLOC_FLAG_HAS_FINALISER = 1,
};
void *gc_alloc(size_t n_bytes, unsigned int alloc_flags);
void gc_free(void *ptr); // does not call finaliser
size_t gc_nbytes(const void *ptr);
void *gc_realloc(void *ptr, size_t n_bytes, bool allow_move);
typedef struct _gc_info_t {
size_t total;
size_t used;
size_t free;
size_t max_free;
size_t num_1block;
size_t num_2block;
size_t max_block;
} gc_info_t;
void gc_info(gc_info_t *info);
void gc_dump_info(const mp_print_t *print);
void gc_dump_alloc_table(const mp_print_t *print);
#endif // MICROPY_INCLUDED_PY_GC_H