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class method

GC.latest_gc_info

(?::Hash[::Symbol, untyped]? hash) -> ::Hash[::Symbol, untyped]

(::Symbol key) -> untyped

GC.latest_gc_info → new_hash

GC.latest_gc_info(key) → value

GC.latest_gc_info(hash) → hash

# File tmp/rubies/ruby-4.1.0-preview1/gc.rb, line 590
def self.latest_gc_info hash_or_key = nil
  if hash_or_key == nil
    hash_or_key = {}
  elsif Primitive.cexpr!("RBOOL(!SYMBOL_P(hash_or_key) && !RB_TYPE_P(hash_or_key, T_HASH))")
    raise TypeError, "non-hash or symbol given"
  end

  Primitive.cstmt! %{
    return rb_gc_latest_gc_info(hash_or_key);
  }
end

With no argument given, returns information about the most recent garbage collection:

Example

GC.latest_gc_info
# =>
{major_by: :force,
 need_major_by: nil,
 gc_by: :method,
 have_finalizer: false,
 immediate_sweep: true,
 state: :none,
 weak_references_count: 0,
 retained_weak_references_count: 0}

With symbol argument key given, returns the value for that key:

Example

GC.latest_gc_info(:gc_by) # => :newobj

With hash argument hash given, returns that hash with GC information merged into its content; this form may be useful in minimizing probe effects:

Example

h = {foo: 0, bar: 1}
GC.latest_gc_info(h)
# =>
{foo: 0,
 bar: 1,
 major_by: nil,
 need_major_by: nil,
 gc_by: :newobj,
 have_finalizer: false,
 immediate_sweep: false,
 state: :sweeping,
 weak_references_count: 0,
 retained_weak_references_count: 0}

Ruby version changes

3.2
- Expose need_major_gc via GC.latest_gc_info. GH-6791

See also .latest_compact_info .malloc_allocated_size .enable .malloc_allocations also in 4.0 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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