From: Peter Zotov <whitequark@...>
Date: 2012-05-15T05:32:16+09:00
Subject: Re: [C exten] Is it safe to use rb_hash_delete() without having the GVL?

Iñaki Baz Castillo писал 14.05.2012 04:32:
> 2012/5/14 SASADA Koichi <ko1@atdot.net>:
>> I believe it is dangerous.
>>
>> Because:
>>
>> (1) rb_hash_delete() can call Ruby's #hash method for each elements.
>> (2) If another thread access to the hash simultaneously, it will be 
>> crash.
>
> Thanks, I understand. However in my case I use Fixnums as keys in the
> hash. I've done several tests and never crashes, maybe because Fixnum
> objects are "untouchable"?

Fixnum instances are immutable and calling #hash should be safe on 
them.
However, point 2) stands: if two threads will access the hash 
simultaneously,
that may and will lead to crashes.

-- 
   WBR, Peter Zotov.