From: mstate@...
Date: 2015-11-12T16:45:48+00:00
Subject: [ruby-core:71465] [Ruby trunk - Bug #11662] Hash#delete causes segmentation fault at 0x00000000001ec8

Issue #11662 has been updated by Mike State.


Yes, we are using threads.  @tmp_handlers is only called from one other location in line #129. 
~~~
@tmp_handlers[id.to_s] = handler
~~~

Should it be safe to add a key to a hash while another thread is deleting a key from the same hash?

Unfortunately, I'm not sure if I can inspect with GDB.  Let me know if it's required and I'll try and figure out how to do it.

----------------------------------------
Bug #11662: Hash#delete causes segmentation fault at 0x00000000001ec8
https://bugs.ruby-lang.org/issues/11662#change-54835

* Author: Mike State
* Status: Feedback
* Priority: Normal
* Assignee: Yukihiro Matsumoto
* ruby -v: ruby 2.3.0dev (2015-11-02 trunk 52423) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
I have seen this bug happen several times, but only when the system is under heavy load.  I have to apologize that don't have any means of easily reproducing it.  I saw the same bug appear (segmentation fault at same line 296) on ruby 2.1.7p400 (2015-08-18 revision 51632) [x86_64-linux].  However on 2.1.7, the Segmentation fault was  0x00000000000000. I have the full core dump for 2.1.7 which I would be happy to provide if it's useful.

Line 296 of client.rb contains:

~~~ruby
if handler = @tmp_handlers.delete(stanza.id)
~~~

~~~
/home/modus/apps/modus_surveyor/bundle/ruby/2.3.0/gems/blather-1.1.4/lib/blather/client/client.rb:296: [BUG] Segmentation fault at 0x00000000001ec8
ruby 2.3.0dev (2015-11-02 trunk 52423) [x86_64-linux]

(snip)
~~~


---Files--------------------------------
bug-11662.log (256 KB)


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