From: Luis Lavena <luislavena@...>
Date: 2012-02-10T22:59:12+09:00
Subject: [ruby-core:42481] [ruby-trunk - Feature #5999] Optimize for faster loading time and win32/file.c refactoring


Issue #5999 has been updated by Luis Lavena.

Category set to core
Assignee set to Usaku NAKAMURA
Target version set to 2.0.0


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Feature #5999: Optimize for faster loading time and win32/file.c refactoring
https://bugs.ruby-lang.org/issues/5999

Author: Hiroshi Shirosaki
Status: Open
Priority: Normal
Assignee: Usaku NAKAMURA
Category: core
Target version: 2.0.0


This was originally discussed at [ruby-core:41799] `Best way to separate implementation specific code?`.

Ruby startup time (loading time) is slow when loading a lot of libraries such as Rails. Some works were done to improve performance such as #3924, but startup is still not fast. Especially ruby on Windows seems much slower than on Unix like OS.
This work is an effort to improve startup time on Windows.

I have updated the patch with help from Luis Lavena. This patch improves loading time a little.

https://gist.github.com/1605263#file_0001_move_rb_file_load_ok_to_win32_file.c.patch


If load_path and loaded_features are large numbers such as rails app, file_load_ok() is called many times against non-existing path.

On Windows, GetFileAttributes() is faster than open(). And open() performance is affected by AntiVirus software's realtime scan.
I confirmed this with NOD32. Microsoft Security Essentials doesn't affect so badly as NOD32. It seems to depend on kinds of antivirus softwares.

Benchmark:
https://gist.github.com/1605263#gistcomment-75650
https://gist.github.com/1448652

Avoiding to call open() against non-existing path by using GetFileAttributes() seems to improve performance.
I used CreateFile() instead of open() because CreateFile() seems a little faster.


Here are rails startup benchmarks.

On Windows 7:

200ms improvement
https://gist.github.com/1605263#gistcomment-82137


On Windows XP:

800ms improvement with NOD32 OFF
1800ms improvement with NOD32 ON
https://gist.github.com/1605263#gistcomment-75644


This fix would be helpful for windows users. I guess most windows users use antivirus softwares.

I confirmed make, make test are OK. make test-all result was same as before patch at the following revision.
ruby 2.0.0dev (2012-02-09 trunk 34511) [i386-mingw32]


At [ruby-core:41831], Matz agreed with replacing file_load_ok.

This is the first work in win32/file.c. The following works (optimize expand_path etc.) into win32/file.c will be done by Luis.
This patch changed configure and Makefile. I also confirmed make with `nmake`(mswin32).

Is this acceptable way?


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