Bug #10485: NoMethodError "undefined method `initialize_copy'" when trying to execute Queue#dup

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.2.0dev (2014-11-07 trunk 48313) [x86_64-linux]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN

[bubo47 (Jakub Jursa)]

Queue#dup raises NoMethodError (Queue#clone as well)

 :001 > q = Queue.new
 => #<Thread::Queue:0x00000001507ca0> 
 :002 > q.dup
NoMethodError: undefined method `initialize_copy' for #<Thread::Queue:0x00000001504c08>
	from (irb):2:in `initialize_dup'
	from (irb):2:in `dup'
	from (irb):2
	from /home/bubo/.rvm/rubies/ruby-head/bin/irb:11:in `<main>'

[nobu (Nobuyoshi Nakada)]

• Related to Bug #9440: Calling methods on a `Queue.new.dup` or `Queue.new.clone` causes Segfault added

[nobu (Nobuyoshi Nakada)]

• Category changed from lib to ext
• Status changed from Open to Feedback

Why do you need to copy Queues?

[bubo47 (Jakub Jursa)]

why not? :)
actually I bumped into this by accident when implementing Queue#to_a (which basically clones self and empties it into new array which it then returns). So it's not really some kind of blocker bug. But since #clone and #dup are methods of Object, I expected them to work on Queues as well.

[nobu (Nobuyoshi Nakada)]

• Related to Feature #8639: Add Queue#each added

[nobu (Nobuyoshi Nakada)]

Not all methods in super classes always work on all subclasses.

Queues hold waiting Threads, and copying it may cause them waken up unexpectedly.

[recursive-madman (Recursive Madman)]

Not all methods in super classes always work on all subclasses.

If a method that works on a superclass doesn't work on a subclass, I would expect the subclass to at least mark it as private and definitely not segfault.

[bubo47 (Jakub Jursa)]

Recursive Madman wrote:

Not all methods in super classes always work on all subclasses.

If a method that works on a superclass doesn't work on a subclass, I would expect the subclass to at least mark it as private and definitely not segfault.

definitely.

[naruse (Yui NARUSE)]

• Target version deleted (2.2.0)

[jeremyevans0 (Jeremy Evans)]

• Status changed from Feedback to Closed