Bug #6867: super in a Mutex#synchronize block

• Status: Closed
• Assignee: tenderlovemaking (Aaron Patterson)
• Target version: 2.0.0
• ruby -v: ruby 2.0.0dev (2012-08-14 trunk 36700) [x86_64-darwin10.8.0]

[Eregon (Benoit Daloze)]

The following code:

require 'thread'

class Parent
def meth
end
end

class Child < Parent
def meth
Mutex.new.synchronize do
super
end
end
end

Child.new.meth

raises

bug_super.rb:13:in block in meth': can't find the method for super, which may be called in an orphan block (NoMethodError) from <internal:prelude>:10:in synchronize'
from bug_super.rb:12:in meth' from bug_super.rb:18:in '

I met the bug with the listen gem: https://github.com/guard/listen/blob/master/lib/listen/adapters/darwin.rb#L22-25 .

[nagachika (Tomoyuki Chikanaga)]

Hi,

This issue seems happen after r36640.

[tenderlovemaking (Aaron Patterson)]

• File fix.patch fix.patch added

I'm hitting this bug in the Rails tests too. It does not need to be a synchronize block. Any method that yields will cause this error:

class A; def self.yielder; yield; end end

class X
  def self.hello; 'hi'; end
end

class Y < X
  def self.hello; A.yielder { super() }; end
end

Y.hello

I've attached a patch with a test and fix. It seems that the loop that walks up the control frames would stop even though there is a valid recipient for that method further up the stack. I'm not incredibly pleased with my patch because it has to do a kind_of for each object as it walks up, but it does fix this bug.

Shugo - do you have a better fix for this, or may I apply this patch?

Thanks.

[shugo (Shugo Maeda)]

• Status changed from Open to Assigned
• Assignee changed from shugo (Shugo Maeda) to tenderlovemaking (Aaron Patterson)

tenderlovemaking (Aaron Patterson) wrote:

Shugo - do you have a better fix for this, or may I apply this patch?

I haven't come up with a better solution. Could you apply the patch?

[mame (Yusuke Endoh)]

• Status changed from Assigned to Closed

The patch was applied at r36784.

--
Yusuke Endoh [e-mail]