ruby/gc/gc_impl.h

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2024-07-12 09:29:14 -04:00
#ifndef GC_GC_IMPL_H
#define GC_GC_IMPL_H
/**
* @author Ruby developers <ruby-core@ruby-lang.org>
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @brief Header for GC implementations introduced in [Feature #20470].
*/
#include "ruby/ruby.h"
#ifndef RB_GC_OBJECT_METADATA_ENTRY_DEFINED
# define RB_GC_OBJECT_METADATA_ENTRY_DEFINED
struct rb_gc_object_metadata_entry {
ID name;
VALUE val;
};
#endif
#ifdef BUILDING_MODULAR_GC
# define GC_IMPL_FN
#else
// `GC_IMPL_FN` is an implementation detail of `!USE_MODULAR_GC` builds
// to have the default GC in the same translation unit as gc.c for
// the sake of optimizer visibility. It expands to nothing unless
// you're the default GC.
//
// For the default GC, do not copy-paste this when implementing
// these functions. This takes advantage of internal linkage winning
// when appearing first. See C99 6.2.2p4.
# define GC_IMPL_FN static
#endif
// Bootup
GC_IMPL_FN void *rb_gc_impl_objspace_alloc(void);
GC_IMPL_FN void rb_gc_impl_objspace_init(void *objspace_ptr);
GC_IMPL_FN void *rb_gc_impl_ractor_cache_alloc(void *objspace_ptr, void *ractor);
GC_IMPL_FN void rb_gc_impl_set_params(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_init(void);
GC_IMPL_FN size_t *rb_gc_impl_heap_sizes(void *objspace_ptr);
// Shutdown
GC_IMPL_FN void rb_gc_impl_shutdown_free_objects(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_objspace_free(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache);
// GC
GC_IMPL_FN void rb_gc_impl_start(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact);
GC_IMPL_FN bool rb_gc_impl_during_gc_p(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_prepare_heap(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_gc_enable(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_gc_disable(void *objspace_ptr, bool finish_current_gc);
GC_IMPL_FN bool rb_gc_impl_gc_enabled_p(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_stress_set(void *objspace_ptr, VALUE flag);
GC_IMPL_FN VALUE rb_gc_impl_stress_get(void *objspace_ptr);
GC_IMPL_FN VALUE rb_gc_impl_config_get(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_config_set(void *objspace_ptr, VALUE hash);
// Object allocation
GC_IMPL_FN VALUE rb_gc_impl_new_obj(void *objspace_ptr, void *cache_ptr, VALUE klass, VALUE flags, VALUE v1, VALUE v2, VALUE v3, bool wb_protected, size_t alloc_size);
GC_IMPL_FN size_t rb_gc_impl_obj_slot_size(VALUE obj);
GC_IMPL_FN size_t rb_gc_impl_heap_id_for_size(void *objspace_ptr, size_t size);
GC_IMPL_FN bool rb_gc_impl_size_allocatable_p(size_t size);
// Malloc
/*
* BEWARE: These functions may or may not run under GVL.
*
* You might want to make them thread-safe.
* Garbage collecting inside is possible if and only if you
* already have GVL. Also raising exceptions without one is a
* total disaster.
*
* When you absolutely cannot allocate the requested amount of
* memory just return NULL (with appropriate errno set).
* The caller side takes care of that situation.
*/
GC_IMPL_FN void *rb_gc_impl_malloc(void *objspace_ptr, size_t size);
GC_IMPL_FN void *rb_gc_impl_calloc(void *objspace_ptr, size_t size);
GC_IMPL_FN void *rb_gc_impl_realloc(void *objspace_ptr, void *ptr, size_t new_size, size_t old_size);
GC_IMPL_FN void rb_gc_impl_free(void *objspace_ptr, void *ptr, size_t old_size);
GC_IMPL_FN void rb_gc_impl_adjust_memory_usage(void *objspace_ptr, ssize_t diff);
// Marking
GC_IMPL_FN void rb_gc_impl_mark(void *objspace_ptr, VALUE obj);
GC_IMPL_FN void rb_gc_impl_mark_and_move(void *objspace_ptr, VALUE *ptr);
GC_IMPL_FN void rb_gc_impl_mark_and_pin(void *objspace_ptr, VALUE obj);
GC_IMPL_FN void rb_gc_impl_mark_maybe(void *objspace_ptr, VALUE obj);
GC_IMPL_FN void rb_gc_impl_mark_weak(void *objspace_ptr, VALUE *ptr);
GC_IMPL_FN void rb_gc_impl_remove_weak(void *objspace_ptr, VALUE parent_obj, VALUE *ptr);
// Compaction
GC_IMPL_FN bool rb_gc_impl_object_moved_p(void *objspace_ptr, VALUE obj);
GC_IMPL_FN VALUE rb_gc_impl_location(void *objspace_ptr, VALUE value);
// Write barriers
GC_IMPL_FN void rb_gc_impl_writebarrier(void *objspace_ptr, VALUE a, VALUE b);
GC_IMPL_FN void rb_gc_impl_writebarrier_unprotect(void *objspace_ptr, VALUE obj);
GC_IMPL_FN void rb_gc_impl_writebarrier_remember(void *objspace_ptr, VALUE obj);
// Heap walking
GC_IMPL_FN void rb_gc_impl_each_objects(void *objspace_ptr, int (*callback)(void *, void *, size_t, void *), void *data);
GC_IMPL_FN void rb_gc_impl_each_object(void *objspace_ptr, void (*func)(VALUE obj, void *data), void *data);
// Finalizers
GC_IMPL_FN void rb_gc_impl_make_zombie(void *objspace_ptr, VALUE obj, void (*dfree)(void *), void *data);
GC_IMPL_FN VALUE rb_gc_impl_define_finalizer(void *objspace_ptr, VALUE obj, VALUE block);
GC_IMPL_FN void rb_gc_impl_undefine_finalizer(void *objspace_ptr, VALUE obj);
GC_IMPL_FN void rb_gc_impl_copy_finalizer(void *objspace_ptr, VALUE dest, VALUE obj);
GC_IMPL_FN void rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr);
// Forking
GC_IMPL_FN void rb_gc_impl_before_fork(void *objspace_ptr);
GC_IMPL_FN void rb_gc_impl_after_fork(void *objspace_ptr, rb_pid_t pid);
// Statistics
GC_IMPL_FN void rb_gc_impl_set_measure_total_time(void *objspace_ptr, VALUE flag);
GC_IMPL_FN bool rb_gc_impl_get_measure_total_time(void *objspace_ptr);
GC_IMPL_FN unsigned long long rb_gc_impl_get_total_time(void *objspace_ptr);
GC_IMPL_FN size_t rb_gc_impl_gc_count(void *objspace_ptr);
GC_IMPL_FN VALUE rb_gc_impl_latest_gc_info(void *objspace_ptr, VALUE key);
GC_IMPL_FN VALUE rb_gc_impl_stat(void *objspace_ptr, VALUE hash_or_sym);
GC_IMPL_FN VALUE rb_gc_impl_stat_heap(void *objspace_ptr, VALUE heap_name, VALUE hash_or_sym);
GC_IMPL_FN const char *rb_gc_impl_active_gc_name(void);
// Miscellaneous
GC_IMPL_FN struct rb_gc_object_metadata_entry *rb_gc_impl_object_metadata(void *objspace_ptr, VALUE obj);
GC_IMPL_FN bool rb_gc_impl_pointer_to_heap_p(void *objspace_ptr, const void *ptr);
GC_IMPL_FN bool rb_gc_impl_garbage_object_p(void *objspace_ptr, VALUE obj);
GC_IMPL_FN void rb_gc_impl_set_event_hook(void *objspace_ptr, const rb_event_flag_t event);
GC_IMPL_FN void rb_gc_impl_copy_attributes(void *objspace_ptr, VALUE dest, VALUE obj);
#undef GC_IMPL_FN
Provide GC.config to disable major GC collections This feature provides a new method `GC.config` that configures internal GC configuration variables provided by an individual GC implementation. Implemented in this PR is the option `full_mark`: a boolean value that will determine whether the Ruby GC is allowed to run a major collection while the process is running. It has the following semantics This feature configures Ruby's GC to only run minor GC's. It's designed to give users relying on Out of Band GC complete control over when a major GC is run. Configuring `full_mark: false` does two main things: * Never runs a Major GC. When the heap runs out of space during a minor and when a major would traditionally be run, instead we allocate more heap pages, and mark objspace as needing a major GC. * Don't increment object ages. We don't promote objects during GC, this will cause every object to be scanned on every minor. This is an intentional trade-off between minor GC's doing more work every time, and potentially promoting objects that will then never be GC'd. The intention behind not aging objects is that users of this feature should use a preforking web server, or some other method of pre-warming the oldgen (like Nakayoshi fork)before disabling Majors. That way most objects that are going to be old will have already been promoted. This will interleave major and minor GC collections in exactly the same what that the Ruby GC runs in versions previously to this. This is the default behaviour. * This new method has the following extra semantics: - `GC.config` with no arguments returns a hash of the keys of the currently configured GC - `GC.config` with a key pair (eg. `GC.config(full_mark: true)` sets the matching config key to the corresponding value and returns the entire known config hash, including the new values. If the key does not exist, `nil` is returned * When a minor GC is run, Ruby sets an internal status flag to determine whether the next GC will be a major or a minor. When `full_mark: false` this flag is ignored and every GC will be a minor. This status flag can be accessed at `GC.latest_gc_info(:needs_major_by)`. Any value other than `nil` means that the next collection would have been a major. Thus it's possible to use this feature to check at a predetermined time, whether a major GC is necessary and run one if it is. eg. After a request has finished processing. ```ruby if GC.latest_gc_info(:needs_major_by) GC.start(full_mark: true) end ``` [Feature #20443]
2024-07-04 15:21:09 +01:00
#endif