Explanation (and bulk of the work is in patch 2/3).

I wrote patch 1/3 over 4 years ago since it was simple and
didn't rely on "newer" Ruby 2.3 features.  Patch 2/3 completes
the change and actually depends on 2.5+; while patch 3/3 updates
the gemspec, docs and dependencies for Ruby 2.5+.

I haven't actually used Ruby 2.5 in a while, but I'm still on
Ruby 2.7 since that's what I have in Debian bullseye
(oldstable).

Patch 2/3 could use an extra set of eyes since it's fairly big,
but passes all tests.

Note: I can't benchmark anything since I have limited (shared)
hardware

Eric Wong (3):
  remove kgio from all read(2) and write(2) wrappers
  kill off remaining kgio uses
  update dependency to Ruby 2.5+

 HACKING                         |  2 +-
 README                          |  2 +-
 lib/unicorn.rb                  |  3 +-
 lib/unicorn/http_request.rb     | 18 ++++-----
 lib/unicorn/http_server.rb      | 38 +++++++----------
 lib/unicorn/oob_gc.rb           |  4 +-
 lib/unicorn/socket_helper.rb    | 50 +++--------------------
 lib/unicorn/stream_input.rb     | 20 +++++----
 lib/unicorn/worker.rb           | 10 ++---
 lib/unicorn/write_splat.rb      |  7 ----
 t/README                        |  2 +-
 t/oob_gc.ru                     |  3 --
 t/oob_gc_path.ru                |  3 --
 test/unit/test_request.rb       | 47 ++++++++-------------
 test/unit/test_socket_helper.rb | 72 +++++++--------------------------
 test/unit/test_stream_input.rb  |  2 +-
 test/unit/test_tee_input.rb     |  2 +-
 unicorn.gemspec                 |  5 +--
 18 files changed, 87 insertions(+), 203 deletions(-)
 delete mode 100644 lib/unicorn/write_splat.rb