[Tarantool-patches] [PATCH v3 0/4] fiber: keep reference to userdata if fiber created once

[Oleg Babin via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

From: Oleg Babin <babinoleg@mail.ru>

This patch reworks approach to fiber management in Lua. Before
this patch each action that should return fiber led to new
userdata creation that was quite slow and made GC suffer. This
patch introduces new field in struct fiber to store a reference to
userdata that was created once for a fiber. It allows speedup
operations as fiber.self() and fiber.id().
Simple benchmark shows that access to fiber storage is faster in
two times, fiber.find() - 2-3 times and fiber.new/create functions
don't have any changes.

Initially changes were inspired by #6210 [1] but current patchset
doesn't introduce anything new just improves performance of
existing functions.
Some results are available also in related github PR [2].

  [1] https://github.com/tarantool/tarantool/issues/6210
  [2] https://github.com/tarantool/tarantool/pull/6280

Changes in v3:
  - Review fixes by Igor
  - New patch to make public LUA_NOREF value

Changes in v2:
  - Review fixes by Vlad and Igor
  - The patch patch that introduced mempool usage is discarded

Oleg Babin (4):
  fiber: rename ref to storage_ref
  fiber: pass struct fiber into lbox_pushfiber instead of id
  lua/utils: make LUA_NOREF value public
  fiber: keep reference to userdata if fiber created once

 src/lib/core/fiber.c        |   5 ++
 src/lib/core/fiber.h        |   7 +-
 src/lua/fiber.c             | 124 ++++++++++++------------------------
 src/lua/utils.c             |   1 +
 test/unit/core_test_utils.c |   2 +
 5 files changed, 53 insertions(+), 86 deletions(-)

-- 
2.32.0