Bug #11200: Memory leak of method entries

• Status: Closed
• Assignee: ko1 (Koichi Sasada)
• Target version: -
• ruby -v: 2.3dev
• Backport: 2.0.0: WONTFIX, 2.1: WONTFIX, 2.2: UNKNOWN

[ko1 (Koichi Sasada)]

def recur
  Class.new{
    define_method(:foo) do
      recur
    end
  }.new.foo
end

begin
  recur
rescue SystemStackError
  retry
end

This program increase memory consumption because method entries in method frames (running method entries) are not freed when classes/modules are freed.

I will solve this issue by changing method frame data structures soon.
However, it will be very big change, it is difficult to apply 2.2 and before.
It is very rare case, so I don't think it is critical issue to fix older versions.

[ko1 (Koichi Sasada)]

• Status changed from Open to Closed

Applied in changeset r50728.

---

• method.h: make rb_method_entry_t a VALUE.
  Motivation and new data structure are described in [Bug #11203].
  This patch also solve the following issues.
  • [Bug #11200] Memory leak of method entries
  • [Bug #11046] callee returns incorrect method name in orphan
    proc
• test/ruby/test_method.rb: add a test for [Bug #11046].
• vm_core.h: remvoe rb_control_frame_t::me. me is located at value
  stack.
• vm_core.h, gc.c, vm_method.c: remove unlinked_method... codes
  because method entries are simple VALUEs.
• method.h: Now, all method entries has own independent method
  definititons. Strictly speaking, this change is not essential,
  but for future changes.
  • rb_method_entry_t::flag is move to rb_method_definition_t::flag.
  • rb_method_definition_t::alias_count is now
    rb_method_definition_t::alias_count_ptr, a pointer to the counter.
• vm_core.h, vm_insnhelper.c (rb_vm_frame_method_entry) added to
  search the current method entry from value stack.
• vm_insnhelper.c (VM_CHECK_MODE): introduced to enable/disable
  assertions.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN to 2.0.0: WONTFIX, 2.1: WONTFIX, 2.2: UNKNOWN