text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * SPDX-FileCopyrightText: 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/mpstate.h"
  #include "py/misc.h"
  
  #define WORDS_PER_BLOCK ((MICROPY_BYTES_PER_GC_BLOCK) / BYTES_PER_WORD)
  #define BYTES_PER_BLOCK (MICROPY_BYTES_PER_GC_BLOCK)
  
  // ptr should be of type void*
  #define VERIFY_PTR(ptr) ( \
          ((uintptr_t)(ptr) & (BYTES_PER_BLOCK - 1)) == 0      /* must be aligned on a block */ \
          && ptr >= (void*)MP_STATE_MEM(gc_pool_start)     /* must be above start of pool */ \
          && ptr < (void*)MP_STATE_MEM(gc_pool_end)        /* must be below end of pool */ \
      )
  
  void gc_init(void *start, void *end);
  void gc_deinit(void);
  
  // 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_ptr(void *ptr);
  void gc_collect_root(void **ptrs, size_t len);
  void gc_collect_end(void);
  
  // Is the gc heap available?
  bool gc_alloc_possible(void);
  void *gc_alloc(size_t n_bytes, bool has_finaliser, bool long_lived);
  
  // Use this function to sweep the whole heap and run all finalisers
  void gc_sweep_all(void);
  
  void gc_free(void *ptr); // does not call finaliser
  size_t gc_nbytes(const void *ptr);
  bool gc_has_finaliser(const void *ptr);
  void *gc_make_long_lived(void *old_ptr);
  void *gc_realloc(void *ptr, size_t n_bytes, bool allow_move);
  
  // Prevents a pointer from ever being freed because it establishes a permanent reference to it. Use
  // very sparingly because it can leak memory.
  bool gc_never_free(void *ptr);
  
  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(void);
  void gc_dump_alloc_table(void);
  
  #endif // MICROPY_INCLUDED_PY_GC_H
  