(92585898fb369c79e7f711465e5934ff4c1879f9)

Registering values to the GC. More...

#include "ruby/internal/config.h"
#include "ruby/assert.h"
#include "ruby/internal/attr/cold.h"
#include "ruby/internal/attr/nonnull.h"
#include "ruby/internal/attr/noreturn.h"
#include "ruby/internal/attr/artificial.h"
#include "ruby/internal/attr/maybe_unused.h"
#include "ruby/internal/attr/pure.h"
#include "ruby/internal/dllexport.h"
#include "ruby/internal/special_consts.h"
#include "ruby/internal/stdbool.h"
#include "ruby/internal/value.h"

Include dependency graph for gc.h:

This graph shows which files directly or indirectly include this file:

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Macros
#define	RUBY_REF_EDGE(s, p) offsetof(s, p)

#define	RUBY_REFS_LIST_PTR(l) (RUBY_DATA_FUNC)(uintptr_t)(l)

#define	RUBY_REF_END SIZE_MAX

#define	RUBY_REFERENCES(t) static const size_t t[]

#define	RUBY_REFERENCES_START(t) RUBY_REFERENCES(t) = {

#define	RUBY_REFERENCES_END RUBY_REF_END, };

#define	USE_RGENGC 1

#define	USE_RGENGC_LOGGING_WB_UNPROTECT 0

#define	RGENGC_WB_PROTECTED_ARRAY 1
	This is a compile-time flag to enable/disable write barrier for struct RArray. More...

#define	RGENGC_WB_PROTECTED_HASH 1
	This is a compile-time flag to enable/disable write barrier for struct RHash. More...

#define	RGENGC_WB_PROTECTED_STRUCT 1
	This is a compile-time flag to enable/disable write barrier for struct RStruct. More...

#define	RGENGC_WB_PROTECTED_STRING 1
	This is a compile-time flag to enable/disable write barrier for struct RString. More...

#define	RGENGC_WB_PROTECTED_OBJECT 1
	This is a compile-time flag to enable/disable write barrier for struct RObject. More...

#define	RGENGC_WB_PROTECTED_REGEXP 1
	This is a compile-time flag to enable/disable write barrier for struct RRegexp. More...

#define	RGENGC_WB_PROTECTED_MATCH 1
	This is a compile-time flag to enable/disable write barrier for struct RMatch. More...

#define	RGENGC_WB_PROTECTED_CLASS 1
	This is a compile-time flag to enable/disable write barrier for struct RClass. More...

#define	RGENGC_WB_PROTECTED_FLOAT 1
	This is a compile-time flag to enable/disable write barrier for struct RFloat. More...

#define	RGENGC_WB_PROTECTED_COMPLEX 1
	This is a compile-time flag to enable/disable write barrier for struct RComplex. More...

#define	RGENGC_WB_PROTECTED_RATIONAL 1
	This is a compile-time flag to enable/disable write barrier for struct RRational. More...

#define	RGENGC_WB_PROTECTED_BIGNUM 1
	This is a compile-time flag to enable/disable write barrier for struct RBignum. More...

#define	RGENGC_WB_PROTECTED_NODE_CREF 1

#define	RB_OBJ_WRITE(old, slot, young) RBIMPL_CAST(rb_obj_write((VALUE)(old), (VALUE *)(slot), (VALUE)(young), __FILE__, __LINE__))
	Declaration of a "back" pointer. More...

#define	RB_OBJ_WRITTEN(old, oldv, young) RBIMPL_CAST(rb_obj_written((VALUE)(old), (VALUE)(oldv), (VALUE)(young), __FILE__, __LINE__))
	Identical to RB_OBJ_WRITE(), except it doesn't write any values, but only a WB declaration. More...

#define	OBJ_PROMOTED_RAW RB_OBJ_PROMOTED_RAW
	Old name of RB_OBJ_PROMOTED_RAW. More...

#define	OBJ_PROMOTED RB_OBJ_PROMOTED
	Old name of RB_OBJ_PROMOTED. More...

#define	OBJ_WB_UNPROTECT RB_OBJ_WB_UNPROTECT
	Old name of RB_OBJ_WB_UNPROTECT. More...

#define	RB_OBJ_WB_UNPROTECT(x) rb_obj_wb_unprotect(x, __FILE__, __LINE__)
	Asserts that the passed object is not fenced by write barriers. More...

#define	RB_OBJ_WB_UNPROTECT_FOR(type, obj) (RGENGC_WB_PROTECTED_##type ? OBJ_WB_UNPROTECT(obj) : obj)
	Identical to RB_OBJ_WB_UNPROTECT(), except it can also assert that the given object is of given type. More...

#define	RGENGC_LOGGING_WB_UNPROTECT rb_gc_unprotect_logging
	This is an implementation detail of rb_obj_wb_unprotect(). More...

Functions
void	rb_memerror (void)
	Triggers out-of-memory error. More...

int	rb_during_gc (void)
	Queries if the GC is busy. More...

void	rb_gc_mark_locations (const VALUE start, const VALUE end)
	Marks objects between the two pointers. More...

void	rb_mark_tbl (struct st_table *tbl)
	Identical to rb_mark_hash(), except it marks only values of the table and leave their associated keys unmarked. More...

void	rb_mark_tbl_no_pin (struct st_table *tbl)
	Identical to rb_mark_tbl(), except it marks objects using rb_gc_mark_movable(). More...

void	rb_mark_set (struct st_table *tbl)
	Identical to rb_mark_hash(), except it marks only keys of the table and leave their associated values unmarked. More...

void	rb_mark_hash (struct st_table *tbl)
	Marks keys and values associated inside of the given table. More...

void	rb_gc_update_tbl_refs (st_table *ptr)
	Updates references inside of tables. More...

void	rb_gc_mark_maybe (VALUE obj)
	Identical to rb_gc_mark(), except it allows the passed value be a non-object. More...

void	rb_gc_mark (VALUE obj)
	Marks an object. More...

void	rb_gc_mark_movable (VALUE obj)
	Maybe this is the only function provided for C extensions to control the pinning of objects, so let us describe it in detail. More...

VALUE	rb_gc_location (VALUE obj)
	Finds a new "location" of an object. More...

void	rb_gc (void)
	Triggers a GC process. More...

void	rb_gc_copy_finalizer (VALUE dst, VALUE src)
	Copy&paste an object's finaliser to another. More...

VALUE	rb_gc_enable (void)
	(Re-) enables GC. More...

VALUE	rb_gc_disable (void)
	Disables GC. More...

VALUE	rb_gc_start (void)
	Identical to rb_gc(), except the return value. More...

VALUE	rb_define_finalizer (VALUE obj, VALUE block)
	Assigns a finaliser for an object. More...

VALUE	rb_undefine_finalizer (VALUE obj)
	Modifies the object so that it has no finalisers at all. More...

size_t	rb_gc_count (void)
	Identical to rb_gc_stat(), with "count" parameter. More...

size_t	rb_gc_stat (VALUE key_or_buf)
	Obtains various GC related profiles. More...

VALUE	rb_gc_latest_gc_info (VALUE key_or_buf)
	Obtains various info regarding the most recent GC run. More...

void	rb_gc_adjust_memory_usage (ssize_t diff)
	Informs that there are external memory usages. More...

void	rb_gc_register_address (VALUE *valptr)
	Inform the garbage collector that the global or static variable pointed by `valptr` stores a live Ruby object that should not be moved. More...

void	rb_global_variable (VALUE *)
	An alias for `rb_gc_register_address()`. More...

void	rb_gc_unregister_address (VALUE *valptr)
	Inform the garbage collector that a pointer previously passed to `rb_gc_register_address()` no longer points to a live Ruby object. More...

void	rb_gc_register_mark_object (VALUE object)
	Inform the garbage collector that `object` is a live Ruby object that should not be moved. More...

void	rb_gc_writebarrier (VALUE old, VALUE young)
	This is the implementation of RB_OBJ_WRITE(). More...

void	rb_gc_writebarrier_unprotect (VALUE obj)
	This is the implementation of RB_OBJ_WB_UNPROTECT(). More...

static bool	RB_OBJ_PROMOTED_RAW (VALUE obj)
	This is the implementation of RB_OBJ_PROMOTED(). More...

static bool	RB_OBJ_PROMOTED (VALUE obj)
	Tests if the object is "promoted" – that is, whether the object experienced one or more GC marks. More...

static VALUE	rb_obj_wb_unprotect (VALUE x, const char *filename, int line)
	This is the implementation of RB_OBJ_WB_UNPROTECT(). More...

static void	rb_gc_force_recycle (VALUE obj)

Detailed Description

Registering values to the GC.

Author: Ruby developers ruby-.nosp@m.core.nosp@m.@ruby.nosp@m.-lan.nosp@m.g.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.

Warning: Symbols prefixed with either RBIMPL or rbimpl are implementation details. Don't take them as canon. They could rapidly appear then vanish. The name (path) of this header file is also an implementation detail. Do not expect it to persist at the place it is now. Developers are free to move it anywhere anytime at will.

Note: To ruby-core: remember that this header can be possibly recursively included from extension libraries written in C++. Do not expect for instance __VA_ARGS__ is always available. We assume C99 for ruby itself but we don't assume languages of extension libraries. They could be written in C++98.

Definition in file gc.h.

Macro Definition Documentation

◆ RB_OBJ_WB_UNPROTECT

#define RB_OBJ_WB_UNPROTECT ( x ) rb_obj_wb_unprotect(x, __FILE__, __LINE__)

Asserts that the passed object is not fenced by write barriers.

Objects of such property do not contribute to generational GCs. They are scanned always.

Parameters

[out] x An object that would not be protected by the barrier.

Definition at line 630 of file gc.h.

◆ RB_OBJ_WB_UNPROTECT_FOR

#define RB_OBJ_WB_UNPROTECT_FOR	(	type,
		obj
	)	(RGENGC_WB_PROTECTED_##type ? OBJ_WB_UNPROTECT(obj) : obj)

Identical to RB_OBJ_WB_UNPROTECT(), except it can also assert that the given object is of given type.

Parameters

[in]	type	One of `ARRAY`, `STRING`, etc.
[out]	obj	An object of `type` that would not be protected.

Definition at line 643 of file gc.h.

◆ RGENGC_LOGGING_WB_UNPROTECT

#define RGENGC_LOGGING_WB_UNPROTECT rb_gc_unprotect_logging

This is an implementation detail of rb_obj_wb_unprotect().

People don't use it directly.

Definition at line 652 of file gc.h.

◆ RGENGC_WB_PROTECTED_ARRAY

#define RGENGC_WB_PROTECTED_ARRAY 1

This is a compile-time flag to enable/disable write barrier for struct RArray.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 446 of file gc.h.

◆ RGENGC_WB_PROTECTED_BIGNUM

#define RGENGC_WB_PROTECTED_BIGNUM 1

This is a compile-time flag to enable/disable write barrier for struct RBignum.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 567 of file gc.h.

◆ RGENGC_WB_PROTECTED_CLASS

#define RGENGC_WB_PROTECTED_CLASS 1

This is a compile-time flag to enable/disable write barrier for struct RClass.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 523 of file gc.h.

◆ RGENGC_WB_PROTECTED_COMPLEX

#define RGENGC_WB_PROTECTED_COMPLEX 1

This is a compile-time flag to enable/disable write barrier for struct RComplex.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 545 of file gc.h.

◆ RGENGC_WB_PROTECTED_FLOAT

#define RGENGC_WB_PROTECTED_FLOAT 1

This is a compile-time flag to enable/disable write barrier for struct RFloat.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 534 of file gc.h.

◆ RGENGC_WB_PROTECTED_HASH

#define RGENGC_WB_PROTECTED_HASH 1

This is a compile-time flag to enable/disable write barrier for struct RHash.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 457 of file gc.h.

◆ RGENGC_WB_PROTECTED_MATCH

#define RGENGC_WB_PROTECTED_MATCH 1

This is a compile-time flag to enable/disable write barrier for struct RMatch.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 512 of file gc.h.

◆ RGENGC_WB_PROTECTED_NODE_CREF

#define RGENGC_WB_PROTECTED_NODE_CREF 1

Deprecated:: This macro once was a thing in the old days, but makes no sense any longer today.

Exists here for backwards compatibility only. You can safely forget about it.

Definition at line 582 of file gc.h.

◆ RGENGC_WB_PROTECTED_OBJECT

#define RGENGC_WB_PROTECTED_OBJECT 1

This is a compile-time flag to enable/disable write barrier for struct RObject.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 490 of file gc.h.

◆ RGENGC_WB_PROTECTED_RATIONAL

#define RGENGC_WB_PROTECTED_RATIONAL 1

This is a compile-time flag to enable/disable write barrier for struct RRational.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 556 of file gc.h.

◆ RGENGC_WB_PROTECTED_REGEXP

#define RGENGC_WB_PROTECTED_REGEXP 1

This is a compile-time flag to enable/disable write barrier for struct RRegexp.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 501 of file gc.h.

◆ RGENGC_WB_PROTECTED_STRING

#define RGENGC_WB_PROTECTED_STRING 1

This is a compile-time flag to enable/disable write barrier for struct RString.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 479 of file gc.h.

◆ RGENGC_WB_PROTECTED_STRUCT

#define RGENGC_WB_PROTECTED_STRUCT 1

This is a compile-time flag to enable/disable write barrier for struct RStruct.

It has to be set at the time ruby itself compiles. Makes no sense for 3rd parties.

Definition at line 468 of file gc.h.

◆ USE_RGENGC

#define USE_RGENGC 1

Deprecated:: This macro once was a thing in the old days, but makes no sense any longer today.

Exists here for backwards compatibility only. You can safely forget about it.

Definition at line 428 of file gc.h.

◆ USE_RGENGC_LOGGING_WB_UNPROTECT

#define USE_RGENGC_LOGGING_WB_UNPROTECT 0

Deprecated:: This macro seems broken.

Setting this to anything other than zero just doesn't compile. We need to KonMari.

Definition at line 435 of file gc.h.

Function Documentation

◆ rb_define_finalizer()

VALUE rb_define_finalizer	(	VALUE	obj,
		VALUE	block
	)

Assigns a finaliser for an object.

Each objects can have objects (typically blocks) that run immediately after that object dies. They are called finalisers of an object. This function associates a finaliser object with a target object.

Note: Note that finalisers run after the object they finalise dies. You cannot for instance call its methods.; If your finaliser references the object it finalises that object loses any chance to become a garbage; effectively leaks memory until the end of the process.

Parameters

[in]	obj	Target to finalise.
[in]	block	Something `call`able.

Exceptions

rb_eRuntimeError	Somehow `obj` cannot have finalisers.
rb_eFrozenError	`obj` is frozen.
rb_eArgError	`block` doesn't respond to `call`.

Returns: The passed block.

Postcondition: block runs after obj dies.

Definition at line 1585 of file gc.c.

◆ rb_during_gc()

int rb_during_gc ( void )

Queries if the GC is busy.

Return values

0	It isn't.
1	It is.

Definition at line 3411 of file gc.c.

◆ rb_gc()

void rb_gc ( void )

Triggers a GC process.

This was the only GC entry point that we had at the beginning. Over time our GC evolved. Now what this function does is just a very simplified variation of the entire GC algorithms. A series of procedures kicked by this API is called a "full" GC.

It immediately scans the entire object space to sort the dead.
It immediately reclaims any single dead bodies to reuse later.

It is worth noting that the procedures above do not include evaluations of finalisers. They run later.

Definition at line 3403 of file gc.c.

Referenced by rb_gc_start(), and rb_reg_region_copy().

◆ rb_gc_adjust_memory_usage()

void rb_gc_adjust_memory_usage ( ssize_t diff )

Informs that there are external memory usages.

Our GC runs when we are running out of memory. The amount of memory, however, can increase/decrease behind-the-scene. For instance DLLs can allocate memories using mmap(2) etc, which are opaque to us. Registering such external allocations using this function enables proper detection of how much memories an object used as a whole. That will trigger GCs more often than it would otherwise. You can also pass negative numbers here, to indicate that such external allocations are gone.

Parameters

[in] diff Amount of memory increased(+)/decreased(-).

Definition at line 4402 of file gc.c.

◆ rb_gc_copy_finalizer()

void rb_gc_copy_finalizer	(	VALUE	dst,
		VALUE	src
	)

Copy&paste an object's finaliser to another.

This is one of the GC utility functions that you can call when you design your own initialize_copy, initialize_dup, initialize_clone.

Parameters

[out]	dst	Destination object.
[in]	src	Source object.

Postcondition: dst and src share the same finaliser.

Definition at line 1500 of file gc.c.

◆ rb_gc_count()

size_t rb_gc_count ( void )

Identical to rb_gc_stat(), with "count" parameter.

Returns: Lifetime total number of runs of GC.

Definition at line 3419 of file gc.c.

◆ rb_gc_disable()

VALUE rb_gc_disable ( void )

Disables GC.

This prevents automatic GC runs when the process is running out of memory. Such situations shall result in rb_memerror(). However this does not prevent users from manually invoking rb_gc(). That should work. People abused this by disabling GC at the beginning of an event loop, process events without GC overheads, then manually force reclaiming garbage at the bottom of the loop. However because our GC is now much smarter than just calling rb_gc(), this technique is proven to be sub-optimal these days. It is believed that there is currently practically no needs of this function.

Return values

RUBY_Qtrue	GC was disabled before.
RUBY_Qfalse	GC was enabled before.

Postcondition: GC is disabled.

Definition at line 3602 of file gc.c.

◆ rb_gc_enable()

VALUE rb_gc_enable ( void )

(Re-) enables GC.

This makes sense only after you called rb_gc_disable().

Return values

RUBY_Qtrue	GC was disabled before.
RUBY_Qfalse	GC was enabled before.

Postcondition: GC is enabled.

Definition at line 3568 of file gc.c.

◆ rb_gc_latest_gc_info()

VALUE rb_gc_latest_gc_info ( VALUE key_or_buf )

Obtains various info regarding the most recent GC run.

This includes for instance the reason of the GC. The parameter can be either a Symbol or a Hash. If a Hash is passed, it is filled with everything currently available. If a Symbol is passed just that portion is returned.

Possible variations of keys you can pass here change from version to version. You can get the list of known keys by passing an empty hash and let it be filled.

Parameters

[in,out] key_or_buf A Symbol, or a Hash.

Exceptions

rb_eTypeError	Neither Symbol nor Hash.
rb_eFrozenError	Frozen hash is passed.

Returns: In case a Hash is passed it returns that hash. Otherwise the profile value associated with the given key is returned.

Postcondition: In case a Hash is passed it is filled with values.

Definition at line 3431 of file gc.c.

◆ rb_gc_location()

VALUE rb_gc_location ( VALUE obj )

Finds a new "location" of an object.

An object can be moved on compaction. This function projects its new abode, or just returns the passed object if not moved. This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dcompact.

Parameters

[in] obj An object, possibly already moved to somewhere else.

Returns: An object, which holds the current contents of former obj.

Definition at line 3037 of file gc.c.

◆ rb_gc_mark()

void rb_gc_mark ( VALUE obj )

Marks an object.

This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Parameters

[out] obj Arbitrary Ruby object.

Postcondition: obj is marked.

Definition at line 2108 of file gc.c.

◆ rb_gc_mark_locations()

void rb_gc_mark_locations	(	const VALUE *	start,
		const VALUE *	end
	)

Marks objects between the two pointers.

This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Precondition: Continuous memory region from start to end shall be fully addressable.

Parameters

[out]	start	Pointer to an array of objects.
[out]	end	Pointer that terminates the array of objects.

Postcondition: Objects from start (included) to end (excluded) are marked.

Definition at line 2174 of file gc.c.

◆ rb_gc_mark_maybe()

void rb_gc_mark_maybe ( VALUE obj )

Identical to rb_gc_mark(), except it allows the passed value be a non-object.

For instance pointers to different type of memory regions are allowed here. Such values are silently ignored. This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Parameters

[out] obj A possible object.

Postcondition: obj is marked, if possible.

Definition at line 2120 of file gc.c.

◆ rb_gc_mark_movable()

void rb_gc_mark_movable ( VALUE obj )

Maybe this is the only function provided for C extensions to control the pinning of objects, so let us describe it in detail.

These days Ruby's GC is copying. As far as an object's physical address is guaranteed unused, it can move around the object space. Our GC engine rearranges these objects after it reclaims unreachable objects from our object space, so that the space is compact (improves memory locality). This is called the "compaction" phase, and works well most of the time... as far as there are no C extensions. C extensions complicate the scenario because Ruby core cannot detect any use of the physical address of an object inside of C functions. In order to prevent memory corruptions, objects observable from C extensions are "pinned"; they stick to where they are born until they die, just in case any C extensions touch their raw pointers. This variant of scheme is called "Mostly-Copying" garbage collector. Authors of C extensions, however, can extremely carefully write them to become compaction-aware. To do so avoid referring to a Ruby object from inside of your struct in the first place. But if that is not possible, use this function from your rb_data_type_struct::dmark then. This way objects marked using it are considered movable. If you chose this way you have to manually fix up locations of such moved pointers using rb_gc_location().

See also: Bartlett, Joel F., "Compacting Garbage Collection with Ambiguous Roots", ACM SIGPLAN Lisp Pointers Volume 1 Issue 6 pp. 3-12, April-May-June, 1988. https://doi.org/10.1145/1317224.1317225

Parameters

[in] obj Object that is movable.

Postcondition: Values stored in tbl are marked.

Definition at line 2090 of file gc.c.

◆ rb_gc_register_address()

void rb_gc_register_address ( VALUE * valptr )

Inform the garbage collector that the global or static variable pointed by valptr stores a live Ruby object that should not be moved.

Note that extensions should use this API on global constants instead of assuming constants defined in Ruby are always alive. Ruby code can remove global constants.

Because this registration itself has a possibility to trigger a GC, this function must be called before any GC-able objects is assigned to the address pointed by valptr.

Definition at line 2828 of file gc.c.

Referenced by rb_global_variable(), and ruby_init_loadpath().

◆ rb_gc_register_mark_object()

void rb_gc_register_mark_object ( VALUE object )

Inform the garbage collector that object is a live Ruby object that should not be moved.

◆ rb_gc_start()

VALUE rb_gc_start ( void )

Identical to rb_gc(), except the return value.

Returns: Always returns RUBY_Qnil.

Definition at line 3396 of file gc.c.

◆ rb_gc_stat()

size_t rb_gc_stat ( VALUE key_or_buf )

Obtains various GC related profiles.

The parameter can be either a Symbol or a Hash. If a Hash is passed, it is filled with everything currently available. If a Symbol is passed just that portion is returned.

Possible variations of keys you can pass here change from version to version. You can get the list of known keys by passing an empty hash and let it be filled.

Parameters

[in,out] key_or_buf A Symbol, or a Hash.

Exceptions

rb_eTypeError	Neither Symbol nor Hash.
rb_eFrozenError	Frozen hash is passed.

Returns: In case a Hash is passed it returns 0. Otherwise the profile value associated with the given key is returned.

Postcondition: In case a Hash is passed it is filled with values.

Definition at line 3468 of file gc.c.

◆ rb_gc_unregister_address()

void rb_gc_unregister_address ( VALUE * valptr )

Inform the garbage collector that a pointer previously passed to rb_gc_register_address() no longer points to a live Ruby object.

Definition at line 2852 of file gc.c.

◆ rb_gc_update_tbl_refs()

void rb_gc_update_tbl_refs ( st_table * ptr )

Updates references inside of tables.

After you marked values using rb_mark_tbl_no_pin(), the objects inside of the table could of course be moved. This function is to fixup those references. You can call this from your rb_data_type_struct::dcompact.

Parameters

[out] ptr A table that potentially includes moved references.

Postcondition: Moved references, if any, are corrected.

Definition at line 2999 of file gc.c.

◆ rb_gc_writebarrier()

void rb_gc_writebarrier	(	VALUE	old,
		VALUE	young
	)

This is the implementation of RB_OBJ_WRITE().

People don't use it directly.

Parameters

[in]	old	An object that points to `young`.
[out]	young	An object that is referenced from `old`.

Definition at line 2752 of file gc.c.

◆ rb_gc_writebarrier_unprotect()

void rb_gc_writebarrier_unprotect ( VALUE obj )

This is the implementation of RB_OBJ_WB_UNPROTECT().

People don't use it directly.

Parameters

[out] obj An object that does not participate in WB.

Definition at line 2758 of file gc.c.

Referenced by rb_obj_wb_unprotect().

◆ rb_global_variable()

void rb_global_variable ( VALUE * var )

An alias for rb_gc_register_address().

Definition at line 2875 of file gc.c.

◆ rb_mark_hash()

void rb_mark_hash ( struct st_table * tbl )

Marks keys and values associated inside of the given table.

This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Parameters

[in] tbl A table to mark.

Postcondition: Objects stored in tbl are marked.

Definition at line 2252 of file gc.c.

◆ rb_mark_set()

void rb_mark_set ( struct st_table * tbl )

Identical to rb_mark_hash(), except it marks only keys of the table and leave their associated values unmarked.

This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Warning: Of course it can break GC. Leave it unused if unsure.

Parameters

[in] tbl A table to mark.

Postcondition: Keys stored in tbl are marked.

Definition at line 2204 of file gc.c.

◆ rb_mark_tbl()

void rb_mark_tbl ( struct st_table * tbl )

Identical to rb_mark_hash(), except it marks only values of the table and leave their associated keys unmarked.

This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Warning: Of course it can break GC. Leave it unused if unsure.

Parameters

[in] tbl A table to mark.

Postcondition: Values stored in tbl are marked.

Definition at line 2408 of file gc.c.

◆ rb_mark_tbl_no_pin()

void rb_mark_tbl_no_pin ( struct st_table * tbl )

Identical to rb_mark_tbl(), except it marks objects using rb_gc_mark_movable().

This is one of the GC utility functions that you can call when you design your own rb_data_type_struct::dmark.

Warning: Of course it can break GC. Leave it unused if unsure.

Parameters

[in] tbl A table to mark.

Postcondition: Values stored in tbl are marked.

Definition at line 2424 of file gc.c.

◆ rb_memerror()

void rb_memerror ( void )

Triggers out-of-memory error.

If possible it raises rb_eNoMemError. But because we are running out of memory that is not always doable. This function tries hard to show something, but ultimately can die silently.

Exceptions

rb_eNoMemError Raises it if possible.

Definition at line 4187 of file gc.c.

◆ RB_OBJ_PROMOTED()

static bool RB_OBJ_PROMOTED ( VALUE obj )

inlinestatic

Tests if the object is "promoted" – that is, whether the object experienced one or more GC marks.

Parameters

[in] obj An object to query.

Return values

true	The object is "promoted".
false	The object is young. Have not experienced GC at all.

Note: Hello, is anyone actively calling this function? @shyouhei have never seen any actual usages outside of the GC implementation itself.

Definition at line 726 of file gc.h.

◆ RB_OBJ_PROMOTED_RAW()

static bool RB_OBJ_PROMOTED_RAW ( VALUE obj )

inlinestatic

This is the implementation of RB_OBJ_PROMOTED().

People don't use it directly.

Parameters

[in] obj An object to query.

Return values

true	The object is "promoted".
false	The object is young. Have not experienced GC at all.

Definition at line 706 of file gc.h.

Referenced by RB_OBJ_PROMOTED().

◆ rb_obj_wb_unprotect()

static VALUE rb_obj_wb_unprotect	(	VALUE	x,
		const char *	filename,
		int	line
	)

inlinestatic

This is the implementation of RB_OBJ_WB_UNPROTECT().

People don't use it directly.

Parameters

[out]	x	An object that does not participate in WB.
[in]	filename	C's `__FILE__` of the caller function.
[in]	line	C's `__LINE__` of the caller function.

Returns: x

Definition at line 746 of file gc.h.

◆ rb_undefine_finalizer()

VALUE rb_undefine_finalizer ( VALUE obj )

Modifies the object so that it has no finalisers at all.

This function is mainly provided for symmetry. No practical usages can be thought of.

Parameters

[out] obj Object to clear its finalisers.

Exceptions

rb_eFrozenError obj is frozen.

Returns: The passed obj.

Postcondition: obj has no finalisers.

Note: There is no way to undefine a specific part of many finalisers that obj could have. All you can do is to clear them all.

(92585898fb369c79e7f711465e5934ff4c1879f9)

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ RB_OBJ_WB_UNPROTECT

◆ RB_OBJ_WB_UNPROTECT_FOR

◆ RGENGC_LOGGING_WB_UNPROTECT

◆ RGENGC_WB_PROTECTED_ARRAY

◆ RGENGC_WB_PROTECTED_BIGNUM

◆ RGENGC_WB_PROTECTED_CLASS

◆ RGENGC_WB_PROTECTED_COMPLEX

◆ RGENGC_WB_PROTECTED_FLOAT

◆ RGENGC_WB_PROTECTED_HASH

◆ RGENGC_WB_PROTECTED_MATCH

◆ RGENGC_WB_PROTECTED_NODE_CREF

◆ RGENGC_WB_PROTECTED_OBJECT

◆ RGENGC_WB_PROTECTED_RATIONAL

◆ RGENGC_WB_PROTECTED_REGEXP

◆ RGENGC_WB_PROTECTED_STRING

◆ RGENGC_WB_PROTECTED_STRUCT

◆ USE_RGENGC

◆ USE_RGENGC_LOGGING_WB_UNPROTECT

Function Documentation

◆ rb_define_finalizer()

◆ rb_during_gc()

◆ rb_gc()

◆ rb_gc_adjust_memory_usage()

◆ rb_gc_copy_finalizer()

◆ rb_gc_count()

◆ rb_gc_disable()

◆ rb_gc_enable()

◆ rb_gc_latest_gc_info()

◆ rb_gc_location()

◆ rb_gc_mark()

◆ rb_gc_mark_locations()

◆ rb_gc_mark_maybe()

◆ rb_gc_mark_movable()

◆ rb_gc_register_address()

◆ rb_gc_register_mark_object()

◆ rb_gc_start()

◆ rb_gc_stat()

◆ rb_gc_unregister_address()

◆ rb_gc_update_tbl_refs()

◆ rb_gc_writebarrier()

◆ rb_gc_writebarrier_unprotect()

◆ rb_global_variable()

◆ rb_mark_hash()

◆ rb_mark_set()

◆ rb_mark_tbl()

◆ rb_mark_tbl_no_pin()

◆ rb_memerror()

◆ RB_OBJ_PROMOTED()

◆ RB_OBJ_PROMOTED_RAW()

◆ rb_obj_wb_unprotect()

◆ rb_undefine_finalizer()