While profiling msgpack-ruby I noticed a very substantial amout of time
spent in `rb_enc_associate_index`, called by `rb_utf8_str_new`.
On that benchmark, `rb_utf8_str_new` is 33% of the total runtime,
in big part because it cause GC to trigger often, but even then
`5.3%` of the total runtime is spent in `rb_enc_associate_index`
called by `rb_utf8_str_new`.
After closer inspection, it appears that it's performing a lot of
safety check we can assert we don't need, and other extra useless
operations, because strings are first created and filled as ASCII-8BIT
and then later reassociated to the desired encoding.
By directly allocating the string with the right encoding, it allow
to skip a lot of duplicated and useless operations.
After this change, the time spent in `rb_utf8_str_new` is down
to `28.4%` of total runtime, and most of that is GC.
[Feature #18576]
Since outright renaming `ASCII-8BIT` is deemed to backward incompatible,
the next best thing would be to only change its `#inspect`, particularly
in exception messages.
when the RUBY_FREE_ON_SHUTDOWN environment variable is set, manually free memory at shutdown.
Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
Co-authored-by: Peter Zhu <peter@peterzhu.ca>
According to MSVC manual (*1), cl.exe can skip including a header file
when that:
- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.
GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).
Sun C lacked #pragma once for a looong time. Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.
This changeset modifies header files so that each of them include
strictly one #ifndef...#endif. I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]
*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
These headers need no rewrite. Just add some minor tweaks, like
addition of #include lines. Mainly cosmetic.
TIMET_MAX_PLUS_ONE was deleted because the macro was used from only
one place (directly write expression there).
One day, I could not resist the way it was written. I finally started
to make the code clean. This changeset is the beginning of a series of
housekeeping commits. It is a simple refactoring; split internal.h into
files, so that we can divide and concur in the upcoming commits. No
lines of codes are either added or removed, except the obvious file
headers/footers. The generated binary is identical to the one before.
