add tag v2_2_9

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v2_2_9@61257 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 777 insertions, 0 deletions

diff --git a/ruby_2_2/ext/objspace/objspace.c b/ruby_2_2/ext/objspace/objspace.c
new file mode 100644
index 0000000000..038461a394
--- /dev/null
+++ b/ruby_2_2/ext/objspace/objspace.c
@@ -0,0 +1,777 @@
+/**********************************************************************
+
+  objspace.c - ObjectSpace extender for MRI.
+
+  $Author$
+  created at: Wed Jun 17 07:39:17 2009
+
+  NOTE: This extension library is only expected to exist with C Ruby.
+
+  All the files in this distribution are covered under the Ruby's
+  license (see the file COPYING).
+
+**********************************************************************/
+
+#include "internal.h"
+#include <ruby/st.h>
+#include <ruby/io.h>
+#include <ruby/re.h>
+#include "node.h"
+#include "gc.h"
+
+/*
+ *  call-seq:
+ *    ObjectSpace.memsize_of(obj) -> Integer
+ *
+ *  Return consuming memory size of obj.
+ *
+ *  Note that the return size is incomplete.  You need to deal with this
+ *  information as only a *HINT*. Especially, the size of +T_DATA+ may not be
+ *  correct.
+ *
+ *  This method is only expected to work with C Ruby.
+ *
+ *  From Ruby 2.2, memsize_of(obj) returns a memory size includes
+  * sizeof(RVALUE).
+ */
+
+static VALUE
+memsize_of_m(VALUE self, VALUE obj)
+{
+    return SIZET2NUM(rb_obj_memsize_of(obj));
+}
+
+struct total_data {
+    size_t total;
+    VALUE klass;
+};
+
+static int
+total_i(void *vstart, void *vend, size_t stride, void *ptr)
+{
+    VALUE v;
+    struct total_data *data = (struct total_data *)ptr;
+
+    for (v = (VALUE)vstart; v != (VALUE)vend; v += stride) {
+	if (RBASIC(v)->flags) {
+	    switch (BUILTIN_TYPE(v)) {
+	      case T_NONE:
+	      case T_ICLASS:
+	      case T_NODE:
+	      case T_ZOMBIE:
+		continue;
+	      case T_CLASS:
+		if (FL_TEST(v, FL_SINGLETON))
+		  continue;
+	      default:
+		if (data->klass == 0 || rb_obj_is_kind_of(v, data->klass)) {
+		    data->total += rb_obj_memsize_of(v);
+		}
+	    }
+	}
+    }
+
+    return 0;
+}
+
+/*
+ *  call-seq:
+ *    ObjectSpace.memsize_of_all([klass]) -> Integer
+ *
+ *  Return consuming memory size of all living objects.
+ *
+ *  If +klass+ (should be Class object) is given, return the total memory size
+ *  of instances of the given class.
+ *
+ *  Note that the returned size is incomplete. You need to deal with this
+ *  information as only a *HINT*. Especially, the size of +T_DATA+ may not be
+ *  correct.
+ *
+ *  Note that this method does *NOT* return total malloc'ed memory size.
+ *
+ *  This method can be defined by the following Ruby code:
+ *
+ *	def memsize_of_all klass = false
+ *  	  total = 0
+ *  	  ObjectSpace.each_object{|e|
+ *  	    total += ObjectSpace.memsize_of(e) if klass == false || e.kind_of?(klass)
+ *  	  }
+ *  	  total
+ *  	end
+ *
+ *  This method is only expected to work with C Ruby.
+ */
+
+static VALUE
+memsize_of_all_m(int argc, VALUE *argv, VALUE self)
+{
+    struct total_data data = {0, 0};
+
+    if (argc > 0) {
+	rb_scan_args(argc, argv, "01", &data.klass);
+    }
+
+    rb_objspace_each_objects(total_i, &data);
+    return SIZET2NUM(data.total);
+}
+
+static int
+set_zero_i(st_data_t key, st_data_t val, st_data_t arg)
+{
+    VALUE k = (VALUE)key;
+    VALUE hash = (VALUE)arg;
+    rb_hash_aset(hash, k, INT2FIX(0));
+    return ST_CONTINUE;
+}
+
+static int
+cos_i(void *vstart, void *vend, size_t stride, void *data)
+{
+    size_t *counts = (size_t *)data;
+    VALUE v = (VALUE)vstart;
+
+    for (;v != (VALUE)vend; v += stride) {
+	if (RBASIC(v)->flags) {
+	    counts[BUILTIN_TYPE(v)] += rb_obj_memsize_of(v);
+	}
+    }
+    return 0;
+}
+
+static VALUE
+type2sym(enum ruby_value_type i)
+{
+    VALUE type;
+    switch (i) {
+#define CASE_TYPE(t) case t: type = ID2SYM(rb_intern(#t)); break;
+	CASE_TYPE(T_NONE);
+	CASE_TYPE(T_OBJECT);
+	CASE_TYPE(T_CLASS);
+	CASE_TYPE(T_MODULE);
+	CASE_TYPE(T_FLOAT);
+	CASE_TYPE(T_STRING);
+	CASE_TYPE(T_REGEXP);
+	CASE_TYPE(T_ARRAY);
+	CASE_TYPE(T_HASH);
+	CASE_TYPE(T_STRUCT);
+	CASE_TYPE(T_BIGNUM);
+	CASE_TYPE(T_FILE);
+	CASE_TYPE(T_DATA);
+	CASE_TYPE(T_MATCH);
+	CASE_TYPE(T_COMPLEX);
+	CASE_TYPE(T_RATIONAL);
+	CASE_TYPE(T_NIL);
+	CASE_TYPE(T_TRUE);
+	CASE_TYPE(T_FALSE);
+	CASE_TYPE(T_SYMBOL);
+	CASE_TYPE(T_FIXNUM);
+	CASE_TYPE(T_UNDEF);
+	CASE_TYPE(T_NODE);
+	CASE_TYPE(T_ICLASS);
+	CASE_TYPE(T_ZOMBIE);
+#undef CASE_TYPE
+      default: rb_bug("type2sym: unknown type (%d)", i);
+    }
+    return type;
+}
+
+/*
+ *  call-seq:
+ *    ObjectSpace.count_objects_size([result_hash]) -> hash
+ *
+ *  Counts objects size (in bytes) for each type.
+ *
+ *  Note that this information is incomplete.  You need to deal with
+ *  this information as only a *HINT*.  Especially, total size of
+ *  T_DATA may not right size.
+ *
+ *  It returns a hash as:
+ *    {:TOTAL=>1461154, :T_CLASS=>158280, :T_MODULE=>20672, :T_STRING=>527249, ...}
+ *
+ *  If the optional argument, result_hash, is given,
+ *  it is overwritten and returned.
+ *  This is intended to avoid probe effect.
+ *
+ *  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.
+ */
+
+static VALUE
+count_objects_size(int argc, VALUE *argv, VALUE os)
+{
+    size_t counts[T_MASK+1];
+    size_t total = 0;
+    enum ruby_value_type i;
+    VALUE hash;
+
+    if (rb_scan_args(argc, argv, "01", &hash) == 1) {
+        if (!RB_TYPE_P(hash, T_HASH))
+            rb_raise(rb_eTypeError, "non-hash given");
+    }
+
+    for (i = 0; i <= T_MASK; i++) {
+	counts[i] = 0;
+    }
+
+    rb_objspace_each_objects(cos_i, &counts[0]);
+
+    if (hash == Qnil) {
+        hash = rb_hash_new();
+    }
+    else if (!RHASH_EMPTY_P(hash)) {
+        st_foreach(RHASH_TBL(hash), set_zero_i, hash);
+    }
+
+    for (i = 0; i <= T_MASK; i++) {
+	if (counts[i]) {
+	    VALUE type = type2sym(i);
+	    total += counts[i];
+	    rb_hash_aset(hash, type, SIZET2NUM(counts[i]));
+	}
+    }
+    rb_hash_aset(hash, ID2SYM(rb_intern("TOTAL")), SIZET2NUM(total));
+    return hash;
+}
+
+static int
+cn_i(void *vstart, void *vend, size_t stride, void *n)
+{
+    size_t *nodes = (size_t *)n;
+    VALUE v = (VALUE)vstart;
+
+    for (; v != (VALUE)vend; v += stride) {
+	if (RBASIC(v)->flags && BUILTIN_TYPE(v) == T_NODE) {
+	    size_t s = nd_type((NODE *)v);
+	    nodes[s]++;
+	}
+    }
+
+    return 0;
+}
+
+/*
+ *  call-seq:
+ *     ObjectSpace.count_nodes([result_hash]) -> hash
+ *
+ *  Counts nodes for each node type.
+ *
+ *  This method is only for MRI developers interested in performance and memory
+ *  usage of Ruby programs.
+ *
+ *  It returns a hash as:
+ *
+ *	{:NODE_METHOD=>2027, :NODE_FBODY=>1927, :NODE_CFUNC=>1798, ...}
+ *
+ *  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.
+ */
+
+static VALUE
+count_nodes(int argc, VALUE *argv, VALUE os)
+{
+    size_t nodes[NODE_LAST+1];
+    size_t i;
+    VALUE hash;
+
+    if (rb_scan_args(argc, argv, "01", &hash) == 1) {
+        if (!RB_TYPE_P(hash, T_HASH))
+            rb_raise(rb_eTypeError, "non-hash given");
+    }
+
+    for (i = 0; i <= NODE_LAST; i++) {
+	nodes[i] = 0;
+    }
+
+    rb_objspace_each_objects(cn_i, &nodes[0]);
+
+    if (hash == Qnil) {
+        hash = rb_hash_new();
+    }
+    else if (!RHASH_EMPTY_P(hash)) {
+        st_foreach(RHASH_TBL(hash), set_zero_i, hash);
+    }
+
+    for (i=0; i<NODE_LAST; i++) {
+	if (nodes[i] != 0) {
+	    VALUE node;
+	    switch (i) {
+#define COUNT_NODE(n) case n: node = ID2SYM(rb_intern(#n)); break;
+		COUNT_NODE(NODE_SCOPE);
+		COUNT_NODE(NODE_BLOCK);
+		COUNT_NODE(NODE_IF);
+		COUNT_NODE(NODE_CASE);
+		COUNT_NODE(NODE_WHEN);
+		COUNT_NODE(NODE_OPT_N);
+		COUNT_NODE(NODE_WHILE);
+		COUNT_NODE(NODE_UNTIL);
+		COUNT_NODE(NODE_ITER);
+		COUNT_NODE(NODE_FOR);
+		COUNT_NODE(NODE_BREAK);
+		COUNT_NODE(NODE_NEXT);
+		COUNT_NODE(NODE_REDO);
+		COUNT_NODE(NODE_RETRY);
+		COUNT_NODE(NODE_BEGIN);
+		COUNT_NODE(NODE_RESCUE);
+		COUNT_NODE(NODE_RESBODY);
+		COUNT_NODE(NODE_ENSURE);
+		COUNT_NODE(NODE_AND);
+		COUNT_NODE(NODE_OR);
+		COUNT_NODE(NODE_MASGN);
+		COUNT_NODE(NODE_LASGN);
+		COUNT_NODE(NODE_DASGN);
+		COUNT_NODE(NODE_DASGN_CURR);
+		COUNT_NODE(NODE_GASGN);
+		COUNT_NODE(NODE_IASGN);
+		COUNT_NODE(NODE_IASGN2);
+		COUNT_NODE(NODE_CDECL);
+		COUNT_NODE(NODE_CVASGN);
+		COUNT_NODE(NODE_CVDECL);
+		COUNT_NODE(NODE_OP_ASGN1);
+		COUNT_NODE(NODE_OP_ASGN2);
+		COUNT_NODE(NODE_OP_ASGN_AND);
+		COUNT_NODE(NODE_OP_ASGN_OR);
+		COUNT_NODE(NODE_OP_CDECL);
+		COUNT_NODE(NODE_CALL);
+		COUNT_NODE(NODE_FCALL);
+		COUNT_NODE(NODE_VCALL);
+		COUNT_NODE(NODE_SUPER);
+		COUNT_NODE(NODE_ZSUPER);
+		COUNT_NODE(NODE_ARRAY);
+		COUNT_NODE(NODE_ZARRAY);
+		COUNT_NODE(NODE_VALUES);
+		COUNT_NODE(NODE_HASH);
+		COUNT_NODE(NODE_RETURN);
+		COUNT_NODE(NODE_YIELD);
+		COUNT_NODE(NODE_LVAR);
+		COUNT_NODE(NODE_DVAR);
+		COUNT_NODE(NODE_GVAR);
+		COUNT_NODE(NODE_IVAR);
+		COUNT_NODE(NODE_CONST);
+		COUNT_NODE(NODE_CVAR);
+		COUNT_NODE(NODE_NTH_REF);
+		COUNT_NODE(NODE_BACK_REF);
+		COUNT_NODE(NODE_MATCH);
+		COUNT_NODE(NODE_MATCH2);
+		COUNT_NODE(NODE_MATCH3);
+		COUNT_NODE(NODE_LIT);
+		COUNT_NODE(NODE_STR);
+		COUNT_NODE(NODE_DSTR);
+		COUNT_NODE(NODE_XSTR);
+		COUNT_NODE(NODE_DXSTR);
+		COUNT_NODE(NODE_EVSTR);
+		COUNT_NODE(NODE_DREGX);
+		COUNT_NODE(NODE_DREGX_ONCE);
+		COUNT_NODE(NODE_ARGS);
+		COUNT_NODE(NODE_ARGS_AUX);
+		COUNT_NODE(NODE_OPT_ARG);
+		COUNT_NODE(NODE_KW_ARG);
+		COUNT_NODE(NODE_POSTARG);
+		COUNT_NODE(NODE_ARGSCAT);
+		COUNT_NODE(NODE_ARGSPUSH);
+		COUNT_NODE(NODE_SPLAT);
+		COUNT_NODE(NODE_TO_ARY);
+		COUNT_NODE(NODE_BLOCK_ARG);
+		COUNT_NODE(NODE_BLOCK_PASS);
+		COUNT_NODE(NODE_DEFN);
+		COUNT_NODE(NODE_DEFS);
+		COUNT_NODE(NODE_ALIAS);
+		COUNT_NODE(NODE_VALIAS);
+		COUNT_NODE(NODE_UNDEF);
+		COUNT_NODE(NODE_CLASS);
+		COUNT_NODE(NODE_MODULE);
+		COUNT_NODE(NODE_SCLASS);
+		COUNT_NODE(NODE_COLON2);
+		COUNT_NODE(NODE_COLON3);
+		COUNT_NODE(NODE_CREF);
+		COUNT_NODE(NODE_DOT2);
+		COUNT_NODE(NODE_DOT3);
+		COUNT_NODE(NODE_FLIP2);
+		COUNT_NODE(NODE_FLIP3);
+		COUNT_NODE(NODE_SELF);
+		COUNT_NODE(NODE_NIL);
+		COUNT_NODE(NODE_TRUE);
+		COUNT_NODE(NODE_FALSE);
+		COUNT_NODE(NODE_ERRINFO);
+		COUNT_NODE(NODE_DEFINED);
+		COUNT_NODE(NODE_POSTEXE);
+		COUNT_NODE(NODE_ALLOCA);
+		COUNT_NODE(NODE_BMETHOD);
+		COUNT_NODE(NODE_MEMO);
+		COUNT_NODE(NODE_IFUNC);
+		COUNT_NODE(NODE_DSYM);
+		COUNT_NODE(NODE_ATTRASGN);
+		COUNT_NODE(NODE_PRELUDE);
+		COUNT_NODE(NODE_LAMBDA);
+#undef COUNT_NODE
+	      default: node = INT2FIX(i);
+	    }
+	    rb_hash_aset(hash, node, SIZET2NUM(nodes[i]));
+	}
+    }
+    return hash;
+}
+
+static int
+cto_i(void *vstart, void *vend, size_t stride, void *data)
+{
+    VALUE hash = (VALUE)data;
+    VALUE v = (VALUE)vstart;
+
+    for (; v != (VALUE)vend; v += stride) {
+	if (RBASIC(v)->flags && BUILTIN_TYPE(v) == T_DATA) {
+	    VALUE counter;
+	    VALUE key = RBASIC(v)->klass;
+
+	    if (key == 0) {
+		const char *name = rb_objspace_data_type_name(v);
+		if (name == 0) name = "unknown";
+		key = ID2SYM(rb_intern(name));
+	    }
+
+	    counter = rb_hash_aref(hash, key);
+	    if (NIL_P(counter)) {
+		counter = INT2FIX(1);
+	    }
+	    else {
+		counter = INT2FIX(FIX2INT(counter) + 1);
+	    }
+
+	    rb_hash_aset(hash, key, counter);
+	}
+    }
+
+    return 0;
+}
+
+/*
+ *  call-seq:
+ *     ObjectSpace.count_tdata_objects([result_hash]) -> hash
+ *
+ *  Counts objects for each +T_DATA+ type.
+ *
+ *  This method is only for MRI developers interested in performance and memory
+ *  usage of Ruby programs.
+ *
+ *  It returns a hash as:
+ *
+ *	{RubyVM::InstructionSequence=>504, :parser=>5, :barrier=>6,
+ *  	 :mutex=>6, Proc=>60, RubyVM::Env=>57, Mutex=>1, Encoding=>99,
+ *  	 ThreadGroup=>1, Binding=>1, Thread=>1, RubyVM=>1, :iseq=>1,
+ *  	 Random=>1, ARGF.class=>1, Data=>1, :autoload=>3, Time=>2}
+ *  	# T_DATA objects existing at startup on r32276.
+ *
+ *  If the optional argument, result_hash, is given, it is overwritten and
+ *  returned. This is intended to avoid probe effect.
+ *
+ *  The contents of the returned hash is implementation specific and may change
+ *  in the future.
+ *
+ *  In this version, keys are Class object or Symbol object.
+ *
+ *  If object is kind of normal (accessible) object, the key is Class object.
+ *  If object is not a kind of normal (internal) object, the key is symbol
+ *  name, registered by rb_data_type_struct.
+ *
+ *  This method is only expected to work with C Ruby.
+ */
+
+static VALUE
+count_tdata_objects(int argc, VALUE *argv, VALUE self)
+{
+    VALUE hash;
+
+    if (rb_scan_args(argc, argv, "01", &hash) == 1) {
+        if (!RB_TYPE_P(hash, T_HASH))
+            rb_raise(rb_eTypeError, "non-hash given");
+    }
+
+    if (hash == Qnil) {
+        hash = rb_hash_new();
+    }
+    else if (!RHASH_EMPTY_P(hash)) {
+        st_foreach(RHASH_TBL(hash), set_zero_i, hash);
+    }
+
+    rb_objspace_each_objects(cto_i, (void *)hash);
+
+    return hash;
+}
+
+static void
+iow_mark(void *ptr)
+{
+    rb_gc_mark((VALUE)ptr);
+}
+
+static size_t
+iow_size(const void *ptr)
+{
+    VALUE obj = (VALUE)ptr;
+    return rb_obj_memsize_of(obj);
+}
+
+static const rb_data_type_t iow_data_type = {
+    "ObjectSpace::InternalObjectWrapper",
+    {iow_mark, 0, iow_size,},
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY
+};
+
+static VALUE rb_mInternalObjectWrapper;
+
+static VALUE
+iow_newobj(VALUE obj)
+{
+    return rb_data_typed_object_alloc(rb_mInternalObjectWrapper, (void *)obj, &iow_data_type);
+}
+
+/* Returns the type of the internal object. */
+static VALUE
+iow_type(VALUE self)
+{
+    VALUE obj = (VALUE)DATA_PTR(self);
+    return type2sym(BUILTIN_TYPE(obj));
+}
+
+/* See Object#inspect. */
+static VALUE
+iow_inspect(VALUE self)
+{
+    VALUE obj = (VALUE)DATA_PTR(self);
+    VALUE type = type2sym(BUILTIN_TYPE(obj));
+
+    return rb_sprintf("#<InternalObject:%p %"PRIsVALUE">", (void *)obj, rb_sym2str(type));
+}
+
+/* Returns the Object#object_id of the internal object. */
+static VALUE
+iow_internal_object_id(VALUE self)
+{
+    VALUE obj = (VALUE)DATA_PTR(self);
+    return rb_obj_id(obj);
+}
+
+struct rof_data {
+    st_table *refs;
+    VALUE internals;
+};
+
+static void
+reachable_object_from_i(VALUE obj, void *data_ptr)
+{
+    struct rof_data *data = (struct rof_data *)data_ptr;
+    VALUE key = obj;
+    VALUE val = obj;
+
+    if (rb_objspace_markable_object_p(obj)) {
+	if (rb_objspace_internal_object_p(obj)) {
+	    val = iow_newobj(obj);
+	    rb_ary_push(data->internals, val);
+	}
+	st_insert(data->refs, key, val);
+    }
+}
+
+static int
+collect_values(st_data_t key, st_data_t value, st_data_t data)
+{
+    VALUE ary = (VALUE)data;
+    rb_ary_push(ary, (VALUE)value);
+    return ST_CONTINUE;
+}
+
+/*
+ *  call-seq:
+ *     ObjectSpace.reachable_objects_from(obj) -> array or nil
+ *
+ *  [MRI specific feature] Return all reachable objects from `obj'.
+ *
+ *  This method returns all reachable objects from `obj'.
+ *
+ *  If `obj' has two or more references to the same object `x', then returned
+ *  array only includes one `x' object.
+ *
+ *  If `obj' is a non-markable (non-heap management) object such as true,
+ *  false, nil, symbols and Fixnums (and Flonum) then it simply returns nil.
+ *
+ *  If `obj' has references to an internal object, then it returns instances of
+ *  ObjectSpace::InternalObjectWrapper class. This object contains a reference
+ *  to an internal object and you can check the type of internal object with
+ *  `type' method.
+ *
+ *  If `obj' is instance of ObjectSpace::InternalObjectWrapper class, then this
+ *  method returns all reachable object from an internal object, which is
+ *  pointed by `obj'.
+ *
+ *  With this method, you can find memory leaks.
+ *
+ *  This method is only expected to work except with C Ruby.
+ *
+ *  Example:
+ *    ObjectSpace.reachable_objects_from(['a', 'b', 'c'])
+ *    #=> [Array, 'a', 'b', 'c']
+ *
+ *    ObjectSpace.reachable_objects_from(['a', 'a', 'a'])
+ *    #=> [Array, 'a', 'a', 'a'] # all 'a' strings have different object id
+ *
+ *    ObjectSpace.reachable_objects_from([v = 'a', v, v])
+ *    #=> [Array, 'a']
+ *
+ *    ObjectSpace.reachable_objects_from(1)
+ *    #=> nil # 1 is not markable (heap managed) object
+ *
+ */
+
+static VALUE
+reachable_objects_from(VALUE self, VALUE obj)
+{
+    if (rb_objspace_markable_object_p(obj)) {
+	VALUE ret = rb_ary_new();
+	struct rof_data data;
+
+	if (rb_typeddata_is_kind_of(obj, &iow_data_type)) {
+	    obj = (VALUE)DATA_PTR(obj);
+	}
+
+	data.refs = st_init_numtable();
+	data.internals = rb_ary_new();
+
+	rb_objspace_reachable_objects_from(obj, reachable_object_from_i, &data);
+
+	st_foreach(data.refs, collect_values, (st_data_t)ret);
+	return ret;
+    }
+    else {
+	return Qnil;
+    }
+}
+
+struct rofr_data {
+    VALUE categories;
+    const char *last_category;
+    VALUE last_category_str;
+    VALUE last_category_objects;
+};
+
+static void
+reachable_object_from_root_i(const char *category, VALUE obj, void *ptr)
+{
+    struct rofr_data *data = (struct rofr_data *)ptr;
+    VALUE category_str;
+    VALUE category_objects;
+
+    if (category == data->last_category) {
+	category_str = data->last_category_str;
+	category_objects = data->last_category_objects;
+    }
+    else {
+	data->last_category = category;
+	category_str = data->last_category_str = rb_str_new2(category);
+	category_objects = data->last_category_objects = rb_hash_new();
+	rb_funcall(category_objects, rb_intern("compare_by_identity"), 0);
+	if (!NIL_P(rb_hash_lookup(data->categories, category_str))) {
+	    rb_bug("reachable_object_from_root_i: category should insert at once");
+	}
+	rb_hash_aset(data->categories, category_str, category_objects);
+    }
+
+    if (rb_objspace_markable_object_p(obj) &&
+	obj != data->categories &&
+	obj != data->last_category_objects) {
+	if (rb_objspace_internal_object_p(obj)) {
+	    obj = iow_newobj(obj);
+	}
+	rb_hash_aset(category_objects, obj, obj);
+    }
+}
+
+static int
+collect_values_of_values(VALUE category, VALUE category_objects, VALUE categories)
+{
+    VALUE ary = rb_ary_new();
+    st_foreach(rb_hash_tbl(category_objects), collect_values, ary);
+    rb_hash_aset(categories, category, ary);
+    return ST_CONTINUE;
+}
+
+/*
+ *  call-seq:
+ *     ObjectSpace.reachable_objects_from_root -> hash
+ *
+ *  [MRI specific feature] Return all reachable objects from root.
+ */
+static VALUE
+reachable_objects_from_root(VALUE self)
+{
+    struct rofr_data data;
+    VALUE hash = data.categories = rb_hash_new();
+    data.last_category = 0;
+
+    rb_funcall(hash, rb_intern("compare_by_identity"), 0);
+    rb_objspace_reachable_objects_from_root(reachable_object_from_root_i, &data);
+    rb_hash_foreach(hash, collect_values_of_values, hash);
+
+    return hash;
+}
+
+void Init_object_tracing(VALUE rb_mObjSpace);
+void Init_objspace_dump(VALUE rb_mObjSpace);
+
+/*
+ * Document-module: ObjectSpace
+ *
+ * The objspace library extends the ObjectSpace module and adds several
+ * methods to get internal statistic information about
+ * object/memory management.
+ *
+ * You need to <code>require 'objspace'</code> to use this extension module.
+ *
+ * Generally, you *SHOULD NOT* use this library if you do not know
+ * about the MRI implementation.  Mainly, this library is for (memory)
+ * profiler developers and MRI developers who need to know about MRI
+ * memory usage.
+ */
+
+void
+Init_objspace(void)
+{
+    VALUE rb_mObjSpace;
+#if 0
+    rb_mObjSpace = rb_define_module("ObjectSpace"); /* let rdoc know */
+#endif
+    rb_mObjSpace = rb_const_get(rb_cObject, rb_intern("ObjectSpace"));
+
+    rb_define_module_function(rb_mObjSpace, "memsize_of", memsize_of_m, 1);
+    rb_define_module_function(rb_mObjSpace, "memsize_of_all", memsize_of_all_m, -1);
+
+    rb_define_module_function(rb_mObjSpace, "count_objects_size", count_objects_size, -1);
+    rb_define_module_function(rb_mObjSpace, "count_nodes", count_nodes, -1);
+    rb_define_module_function(rb_mObjSpace, "count_tdata_objects", count_tdata_objects, -1);
+
+    rb_define_module_function(rb_mObjSpace, "reachable_objects_from", reachable_objects_from, 1);
+    rb_define_module_function(rb_mObjSpace, "reachable_objects_from_root", reachable_objects_from_root, 0);
+
+    /*
+     * This class is used as a return value from
+     * ObjectSpace::reachable_objects_from.
+     *
+     * When ObjectSpace::reachable_objects_from returns an object with
+     * references to an internal object, an instance of this class is returned.
+     *
+     * You can use the #type method to check the type of the internal object.
+     */
+    rb_mInternalObjectWrapper = rb_define_class_under(rb_mObjSpace, "InternalObjectWrapper", rb_cObject);
+    rb_define_method(rb_mInternalObjectWrapper, "type", iow_type, 0);
+    rb_define_method(rb_mInternalObjectWrapper, "inspect", iow_inspect, 0);
+    rb_define_method(rb_mInternalObjectWrapper, "internal_object_id", iow_internal_object_id, 0);
+
+    Init_object_tracing(rb_mObjSpace);
+    Init_objspace_dump(rb_mObjSpace);
+}