class method

ObjectSpace.count_symbols

(?::Hash[::Symbol, ::Integer] result_hash) -> ::Hash[::Symbol, ::Integer]

ObjectSpace.count_symbols([result_hash]) → hash

ext/objspace/objspace.c View on GitHub ↗

static VALUE
count_symbols(int argc, VALUE *argv, VALUE os)
{
    struct dynamic_symbol_counts dynamic_counts = {0, 0};
    VALUE hash = setup_hash(argc, argv);

    size_t immortal_symbols = rb_sym_immortal_count();
    each_object_with_flags(cs_i, &dynamic_counts);

    rb_hash_aset(hash, ID2SYM(rb_intern("mortal_dynamic_symbol")),   SIZET2NUM(dynamic_counts.mortal));
    rb_hash_aset(hash, ID2SYM(rb_intern("immortal_dynamic_symbol")), SIZET2NUM(dynamic_counts.immortal));
    rb_hash_aset(hash, ID2SYM(rb_intern("immortal_static_symbol")),  SIZET2NUM(immortal_symbols - dynamic_counts.immortal));
    rb_hash_aset(hash, ID2SYM(rb_intern("immortal_symbol")),         SIZET2NUM(immortal_symbols));

    return hash;
}

Counts symbols for each Symbol type.

This method is only for MRI developers interested in performance and memory usage of Ruby programs.

If the optional argument, result_hash, is given, it is overwritten and returned. This is intended to avoid probe effect.

Note: The contents of the returned hash is implementation defined. It may be changed in future.

This method is only expected to work with C Ruby.

On this version of MRI, they have 3 types of Symbols (and 1 total counts).

* mortal_dynamic_symbol: GC target symbols (collected by GC)
* immortal_dynamic_symbol: Immortal symbols promoted from dynamic symbols (do not collected by GC)
* immortal_static_symbol: Immortal symbols (do not collected by GC)
* immortal_symbol: total immortal symbols (immortal_dynamic_symbol+immortal_static_symbol)

See also .count_objects_size .count_tdata_objects .count_objects .define_finalizer also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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