Issue #10191 has been updated by Usaku NAKAMURA. Backport changed from 2.0.0: REQUIRED, 2.1: DONE to 2.0.0: DONE, 2.1: DONE backported into `ruby_2_0_0` at r47548. In my environment, I don't have to change the limit of assert_no_memory_leak. I may change it if CIs report some problems. ---------------------------------------- Bug #10191: Possible memory leak using dup and setting an unassigned instance variable (Windows) https://bugs.ruby-lang.org/issues/10191#change-48860 * Author: Ben Hellerstein * Status: Closed * Priority: Normal * Assignee: * Category: * Target version: * ruby -v: 1.9.3p327 (2012-11-10) [i386-mingw32] (also present in 2.0.0p481 [i386-mingw32] from rubyinstaller.org) * Backport: 2.0.0: DONE, 2.1: DONE ---------------------------------------- Steps: 1. Run the following code (tested on Window 7): ~~~ruby class Leaky attr_accessor :v def leak; d = dup; d.v = nil; end end l = Leaky.new while true; l.leak; end ~~~ 2. Watch the memory usage in Task Manager or equivalent Expected result: Infinite loop, memory usage fairly stable (as GC cleans up) Actual result: Interpreter consumes more and more memory, and eventually throws the following exception: "in `dup': failed to allocate memory (NoMemoryError)." Presumably, this is a memory leak. Workaround: If you manually set the instance variable before dup-ing, memory usage is stable. Accordingly, this code does not appear to leak memory: ~~~ruby class NonLeaky attr_accessor :v def leak; @v ||= nil; d = dup; d.v = nil; end end l = NonLeaky.new while true; l.leak; end ~~~ -- https://bugs.ruby-lang.org/