1berry/ruby
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

[DOC] Update comment about how object ID is calculated

Browse Source 
The object ID no longer treats symbols in a special way so we can simplify
the comment about how it is calculated.
This commit is contained in:
Peter Zhu 2024-08-08 15:03:40 -04:00
parent d095474113
commit 264175dbb9
Notes: git 2024-08-14 14:51:25 +00:00 
Merged: https://github.com/ruby/ruby/pull/11346
1 changed files with 4 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
gc.c
View File

@ -1716,35 +1716,10 @@ rb_memory_id(VALUE obj)
VALUE
rb_obj_id(VALUE obj)
{
/*
* 32-bit VALUE space
* MSB ------------------------ LSB
* false 00000000000000000000000000000000
* true 00000000000000000000000000000010
* nil 00000000000000000000000000000100
* undef 00000000000000000000000000000110
* symbol ssssssssssssssssssssssss00001110
* object oooooooooooooooooooooooooooooo00 = 0 (mod sizeof(RVALUE))
* fixnum fffffffffffffffffffffffffffffff1
*
* object_id space
* LSB
* false 00000000000000000000000000000000
* true 00000000000000000000000000000010
* nil 00000000000000000000000000000100
* undef 00000000000000000000000000000110
* symbol 000SSSSSSSSSSSSSSSSSSSSSSSSSSS0 S...S % A = 4 (S...S = s...s * A + 4)
* object oooooooooooooooooooooooooooooo0 o...o % A = 0
* fixnum fffffffffffffffffffffffffffffff1 bignum if required
*
* where A = sizeof(RVALUE)/4
*
* sizeof(RVALUE) is
* 20 if 32-bit, double is 4-byte aligned
* 24 if 32-bit, double is 8-byte aligned
* 40 if 64-bit
*/
/* If obj is an immediate, the object ID is obj directly converted to a Numeric.
* Otherwise, the object ID is a Numeric that is a non-zero multiple of
* (RUBY_IMMEDIATE_MASK + 1) which guarantees that it does not collide with
* any immediates. */
return rb_find_object_id(rb_gc_get_objspace(), obj, rb_gc_impl_object_id);
}