Bug #11203: Change method entries into VALUE

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.0.0: WONTFIX, 2.1: WONTFIX, 2.2: WONTFIX

[ko1 (Koichi Sasada)]

Now, rb_method_entry_t is an allocated data pointed from method tables (class/module has) and from control frame stacks.

I will change this data structure to make VALUE (T_IMEMO/ment).
And I put them onto value frames instead of control frame stacks.

This change has several advantages.

• Solve these issues.
  • [Bug #11200] Memory leak of method entries
  • [Bug #11046] __callee__ returns incorrect method name in orphan proc
• Simplify sweeping process of method entry
• We can remove rb_control_frame_t::me
• No need to push CREF for every method invocation. Method entries know required CREF.
• We can share per method CREF only for make them public visibility scope.
• We can introduce other optimization techniques.
  • We can remove rb_control_frame_t::klass field because method entries can manipulate this information.
  • We can introduce new method cache mechanism (maybe).

The following pictures show how SVAR/CREF/MENT are located at value stacks.

The following picture shows how alias was implemented.

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)

[normalperson (Eric Wong)]

I cannot view images at the moment, but I strongly approve of using
VALUE types more in our internals for the same reasons you describe.

[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

[nagachika (Tomoyuki Chikanaga)]

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