gc.h

#ifndef GC_GC_H
#define GC_GC_H
#include "ruby/ruby.h"
#include "ruby/assert.h"
 
#include "ruby/thread_native.h"
#include "ruby/debug.h"
 
#ifndef VM_CHECK_MODE
# define VM_CHECK_MODE RUBY_DEBUG
#endif
 
// From ractor_core.h
#ifndef RACTOR_CHECK_MODE
# define RACTOR_CHECK_MODE (VM_CHECK_MODE || RUBY_DEBUG) && (SIZEOF_UINT64_T == SIZEOF_VALUE)
#endif
 
struct rb_gc_vm_context {
    struct rb_execution_context_struct *ec;
};
 
typedef int (*vm_table_foreach_callback_func)(VALUE value, void *data);
typedef int (*vm_table_update_callback_func)(VALUE *value, void *data);
 
enum rb_gc_vm_weak_tables {
    RB_GC_VM_CI_TABLE,
    RB_GC_VM_OVERLOADED_CME_TABLE,
    RB_GC_VM_GLOBAL_SYMBOLS_TABLE,
    RB_GC_VM_GENERIC_FIELDS_TABLE,
    RB_GC_VM_FROZEN_STRINGS_TABLE,
    RB_GC_VM_WEAK_TABLE_COUNT
};
 
#define RB_GC_VM_LOCK() rb_gc_vm_lock(__FILE__, __LINE__)
#define RB_GC_VM_UNLOCK(lev) rb_gc_vm_unlock(lev, __FILE__, __LINE__)
#define RB_GC_VM_LOCK_NO_BARRIER() rb_gc_vm_lock_no_barrier(__FILE__, __LINE__)
#define RB_GC_VM_UNLOCK_NO_BARRIER(lev) rb_gc_vm_unlock_no_barrier(lev, __FILE__, __LINE__)
 
#if USE_MODULAR_GC
# define MODULAR_GC_FN
#else
// This takes advantage of internal linkage winning when appearing first.
// See C99 6.2.2p4.
# define MODULAR_GC_FN static
#endif
 
#if USE_MODULAR_GC
RUBY_SYMBOL_EXPORT_BEGIN
#endif
 
// These functions cannot be defined as static because they are used by other
// files in Ruby.
size_t rb_size_mul_or_raise(size_t x, size_t y, VALUE exc);
void rb_objspace_reachable_objects_from(VALUE obj, void (func)(VALUE, void *), void *data);
const char *rb_raw_obj_info(char *const buff, const size_t buff_size, VALUE obj);
const char *rb_obj_info(VALUE obj);
size_t rb_obj_memsize_of(VALUE obj);
bool ruby_free_at_exit_p(void);
void rb_objspace_reachable_objects_from_root(void (func)(const char *category, VALUE, void *), void *passing_data);
void rb_gc_verify_shareable(VALUE);
 
MODULAR_GC_FN unsigned int rb_gc_vm_lock(const char *file, int line);
MODULAR_GC_FN void rb_gc_vm_unlock(unsigned int lev, const char *file, int line);
MODULAR_GC_FN unsigned int rb_gc_vm_lock_no_barrier(const char *file, int line);
MODULAR_GC_FN void rb_gc_vm_unlock_no_barrier(unsigned int lev, const char *file, int line);
MODULAR_GC_FN void rb_gc_vm_barrier(void);
MODULAR_GC_FN void rb_gc_vm_each_objspace(void (*func)(void *objspace, void *data), void *data);
MODULAR_GC_FN size_t rb_gc_vm_zombie_total_pages(void);
MODULAR_GC_FN unsigned int rb_gc_vm_ractor_count(void);
MODULAR_GC_FN void rb_gc_vm_refresh_zombie_pages(void);
/* No MODULAR_GC_FN: the VM side (ractor.c) calls this too, so it needs external
 * linkage even in a non-modular build (see internal/gc.h). */
bool rb_gc_single_objspace_p(void);
/* Clear the "absorbed" flag once a global GC finishes (see rb_gc_single_objspace_p).
 * No MODULAR_GC_FN, for the same reason as above. */
void rb_gc_reset_absorbed_since_global_gc(void);
MODULAR_GC_FN size_t rb_gc_obj_optimal_size(VALUE obj);
MODULAR_GC_FN void rb_gc_mark_children(void *objspace, VALUE obj);
MODULAR_GC_FN void rb_gc_vm_weak_table_foreach(vm_table_foreach_callback_func callback, vm_table_update_callback_func update_callback, void *data, bool weak_only, enum rb_gc_vm_weak_tables table);
/* The global GC's weak pass over generic_fields (called from a gc-impl). */
MODULAR_GC_FN void rb_gc_vm_generic_fields_mark_foreach(int (*cb)(VALUE key, VALUE val, void *arg), void *arg);
MODULAR_GC_FN void rb_gc_vm_generic_fields_drain_dead(bool (*is_dead)(VALUE key));
/* Exemptions for the shareable containment verifier (called from a gc-impl). */
MODULAR_GC_FN VALUE rb_gc_vm_top_self(void);
MODULAR_GC_FN void rb_gc_update_object_references(void *objspace, VALUE obj);
MODULAR_GC_FN void rb_gc_update_vm_references(void *objspace);
MODULAR_GC_FN void rb_gc_event_hook(VALUE obj, rb_event_flag_t event);
MODULAR_GC_FN void *rb_gc_get_objspace(void);
MODULAR_GC_FN void rb_gc_run_obj_finalizer(VALUE objid, long count, VALUE (*callback)(long i, void *data), void *data);
MODULAR_GC_FN void rb_gc_set_pending_interrupt(void);
MODULAR_GC_FN void rb_gc_trigger_finalize_deferred(void *objspace, rb_postponed_job_handle_t pjob);
MODULAR_GC_FN void rb_gc_unset_pending_interrupt(void);
MODULAR_GC_FN void rb_gc_obj_free_vm_weak_references(VALUE obj);
MODULAR_GC_FN bool rb_gc_obj_free(void *objspace, VALUE obj);
MODULAR_GC_FN void rb_gc_save_machine_context(void);
MODULAR_GC_FN void rb_gc_mark_roots(void *objspace, const char **categoryp);
MODULAR_GC_FN bool rb_gc_multi_ractor_p(void);
MODULAR_GC_FN bool rb_gc_ever_multi_ractor_p(void);
/* Process-wide GC disable flag (GC.disable / rb_gc_disable).  Every GC trigger in
 * an impl checks it, so disabling stops automatic GC in every Ractor.  The
 * per-objspace switch is objspace->flags.dont_gc. */
MODULAR_GC_FN bool rb_gc_gc_disabled_global_p(void);
MODULAR_GC_FN bool rb_gc_shutdown_call_finalizer_p(VALUE obj);
MODULAR_GC_FN void rb_gc_obj_changed_slot_size(VALUE obj, size_t slot_size);
MODULAR_GC_FN void rb_gc_prepare_heap_process_object(VALUE obj);
MODULAR_GC_FN bool rb_memerror_reentered(void);
MODULAR_GC_FN bool rb_obj_id_p(VALUE);
MODULAR_GC_FN void rb_gc_before_updating_jit_code(void);
MODULAR_GC_FN void rb_gc_after_updating_jit_code(void);
MODULAR_GC_FN bool rb_gc_obj_shareable_p(VALUE);
MODULAR_GC_FN void rb_gc_rp(VALUE);
MODULAR_GC_FN void rb_gc_handle_weak_references(VALUE obj);
MODULAR_GC_FN bool rb_gc_obj_needs_cleanup_p(VALUE obj);
 
void rb_gc_initialize_vm_context(struct rb_gc_vm_context *context);
#if USE_MODULAR_GC
MODULAR_GC_FN bool rb_gc_event_hook_required_p(rb_event_flag_t event);
MODULAR_GC_FN void *rb_gc_get_ractor_newobj_cache(void);
MODULAR_GC_FN void rb_gc_move_obj_during_marking(VALUE from, VALUE to);
MODULAR_GC_FN void rb_gc_print_backtrace();
#endif
 
#if USE_MODULAR_GC
RUBY_SYMBOL_EXPORT_END
#endif
 
void rb_ractor_finish_marking(bool full_mark);
 
// -------------------Private section begin------------------------
// Functions in this section are private to the default GC and gc.c
 
#ifdef BUILDING_MODULAR_GC
RBIMPL_WARNING_PUSH()
RBIMPL_WARNING_IGNORED(-Wunused-function)
#endif
 
/* RGENGC_CHECK_MODE
 * 0: disable all assertions
 * 1: enable assertions (to debug RGenGC)
 * 2: enable internal consistency check at each GC (for debugging)
 * 3: enable internal consistency check at each GC steps (for debugging)
 * 4: enable liveness check
 * 5: show all references
 */
#ifndef RGENGC_CHECK_MODE
# define RGENGC_CHECK_MODE  0
#endif
 
#ifndef GC_ASSERT
# define GC_ASSERT(expr, ...) RUBY_ASSERT_MESG_WHEN(RGENGC_CHECK_MODE > 0, expr, #expr RBIMPL_VA_OPT_ARGS(__VA_ARGS__))
#endif
 
static int
hash_foreach_replace_value(st_data_t key, st_data_t value, st_data_t argp, int error)
{
    if (rb_gc_location((VALUE)value) != (VALUE)value) {
        return ST_REPLACE;
    }
    return ST_CONTINUE;
}
 
static int
hash_replace_ref_value(st_data_t *key, st_data_t *value, st_data_t argp, int existing)
{
    rb_gc_update_moved((VALUE *)value);
 
    return ST_CONTINUE;
}
 
static void
gc_ref_update_table_values_only(st_table *tbl)
{
    if (!tbl || tbl->num_entries == 0) return;
 
    if (st_foreach_with_replace(tbl, hash_foreach_replace_value, hash_replace_ref_value, 0)) {
        rb_raise(rb_eRuntimeError, "hash modified during iteration");
    }
}
 
static int
gc_mark_tbl_no_pin_i(st_data_t key, st_data_t value, st_data_t data)
{
    rb_gc_mark_movable((VALUE)value);
 
    return ST_CONTINUE;
}
 
static int
gc_mark_set_no_pin_i(st_data_t key, st_data_t value, st_data_t data)
{
    rb_gc_mark_movable((VALUE)key);
 
    return ST_CONTINUE;
}
 
static int
hash_foreach_replace(st_data_t key, st_data_t value, st_data_t argp, int error)
{
    if (rb_gc_location((VALUE)key) != (VALUE)key) {
        return ST_REPLACE;
    }
 
    if (rb_gc_location((VALUE)value) != (VALUE)value) {
        return ST_REPLACE;
    }
 
    return ST_CONTINUE;
}
 
static int
hash_replace_ref(st_data_t *key, st_data_t *value, st_data_t argp, int existing)
{
    rb_gc_update_moved((VALUE *)key);
    rb_gc_update_moved((VALUE *)value);
 
    return ST_CONTINUE;
}
 
static void
gc_update_table_refs(st_table *tbl)
{
    if (!tbl || tbl->num_entries == 0) return;
 
    if (st_foreach_with_replace(tbl, hash_foreach_replace, hash_replace_ref, 0)) {
        rb_raise(rb_eRuntimeError, "hash modified during iteration");
    }
}
 
static inline size_t
xmalloc2_size(const size_t count, const size_t elsize)
{
    return rb_size_mul_or_raise(count, elsize, rb_eArgError);
}
 
static VALUE
type_sym(size_t type)
{
    switch (type) {
#define COUNT_TYPE(t) case (t): return ID2SYM(rb_intern(#t)); break;
        COUNT_TYPE(T_NONE);
        COUNT_TYPE(T_OBJECT);
        COUNT_TYPE(T_CLASS);
        COUNT_TYPE(T_MODULE);
        COUNT_TYPE(T_FLOAT);
        COUNT_TYPE(T_STRING);
        COUNT_TYPE(T_REGEXP);
        COUNT_TYPE(T_ARRAY);
        COUNT_TYPE(T_HASH);
        COUNT_TYPE(T_STRUCT);
        COUNT_TYPE(T_BIGNUM);
        COUNT_TYPE(T_FILE);
        COUNT_TYPE(T_DATA);
        COUNT_TYPE(T_MATCH);
        COUNT_TYPE(T_COMPLEX);
        COUNT_TYPE(T_RATIONAL);
        COUNT_TYPE(T_NIL);
        COUNT_TYPE(T_TRUE);
        COUNT_TYPE(T_FALSE);
        COUNT_TYPE(T_SYMBOL);
        COUNT_TYPE(T_FIXNUM);
        COUNT_TYPE(T_IMEMO);
        COUNT_TYPE(T_UNDEF);
        COUNT_TYPE(T_NODE);
        COUNT_TYPE(T_ICLASS);
        COUNT_TYPE(T_ZOMBIE);
        COUNT_TYPE(T_MOVED);
#undef COUNT_TYPE
        default:              return SIZET2NUM(type); break;
    }
}
 
#ifdef BUILDING_MODULAR_GC
RBIMPL_WARNING_POP()
#endif
// -------------------Private section end------------------------
 
#endif