ruby/mmtk@290a2aec4e

The combination of `&` and `&&` is confusing.

It should not be exposed because it is so implementation specific that
it is only used in gc.c even within the entire Ruby source tree.

The flags for `rb_data_type_t::flags` are public constants for
defining `rb_data_type_t`.  The embedded data flag and mask are
internal implementation detail.

… avoid an extra memchr searching the remaining characters when no more backslashes exist.

ruby/json@d21d9362fa

ruby/json@976ba36629

Co-Authored-By: Jean Boussier <[email protected]>

A plain `char` may be `signed` or `unsigned` depending on the
implementation.  Also, bitwise ORing of `signed` values ​​is not
guaranteed to be `signed`.  To ensure portability, should logical-OR
each comparison, but casting to `signed char` is usually sufficient.

ruby/json@8ad744c532

This commit allows objects that are safe to be freed in parallel to do so.
A decrease in object freeing time can be seen in profiles.

The benchmarks don't show much difference.

Before:

--------------  --------------------  ----------  ---------
bench           sequential free (ms)  stddev (%)  RSS (MiB)
activerecord    242.3                 7.4         84.3
chunky-png      439.1                 0.6         75.6
erubi-rails     1221.2                4.2         132.7
hexapdf         1544.8                1.8         429.1
liquid-c        42.7                  7.4         48.5
liquid-compile  41.4                  8.3         52.2
liquid-render   100.6                 3.0         56.8
mail            108.9                 2.1         65.1
psych-load      1536.9                0.6         43.4
railsbench      1633.5                2.6         146.2
rubocop         126.5                 15.8        142.1
ruby-lsp        129.6                 9.7         112.2
sequel          47.9                  6.5         44.6
shipit          1152.0                2.7         315.2
--------------  --------------------  ----------  ---------

After:

--------------  ------------------  ----------  ---------
bench           parallel free (ms)  stddev (%)  RSS (MiB)
activerecord    235.1               5.5         87.4
chunky-png      440.8               0.8         68.1
erubi-rails     1105.3              0.8         128.0
hexapdf         1578.3              4.1         405.1
liquid-c        42.6                7.1         48.4
liquid-compile  41.5                8.1         52.1
liquid-render   101.2               2.8         53.3
mail            109.7               2.7         64.8
psych-load      1567.7              1.1         44.4
railsbench      1644.9              1.9         150.9
rubocop         125.6               15.4        148.5
ruby-lsp        127.9               5.8         104.6
sequel          48.2                6.1         44.1
shipit          1215.3              4.7         320.5
--------------  ------------------  ----------  ---------

ruby/mmtk@4f0b5fd2eb

This makes it easier to visualize in profilers which one is non-parallel.

ruby/mmtk@ba68b2ef3b

The argument to `is_data_encoding` is assumed to be `T_DATA`.

It sometimes pins itself when it is in the overloaded_cme table.

str_duplicate_setup_heap is missing a call to rb_gc_register_pinning_obj
that STR_SET_SHARED correctly calls.

Thread::Queue spends a significant amount of time in array functions,
checking for invariants we know aren't a problem, and whether the backing
array need to reordered.

By using a ring buffer we can remove a lot of overhead (~23% faster).

```
$ hyperfine './miniruby --yjit /tmp/q.rb' './miniruby-qrb --yjit /tmp/q.rb'
Benchmark 1: ./miniruby --yjit /tmp/q.rb
  Time (mean ± σ):      1.050 s ±  0.191 s    [User: 0.988 s, System: 0.004 s]
  Range (min … max):    0.984 s …  1.595 s    10 runs

Benchmark 2: ./miniruby-qrb --yjit /tmp/q.rb
  Time (mean ± σ):     844.2 ms ±   3.1 ms    [User: 840.4 ms, System: 2.8 ms]
  Range (min … max):   838.6 ms … 848.9 ms    10 runs

Summary
  ./miniruby-qrb --yjit /tmp/q.rb ran
    1.24 ± 0.23 times faster than ./miniruby --yjit /tmp/q.rb
```

```
q = Queue.new([1, 2, 3, 4, 5, 6, 7, 8])
i = 2_000_000
while i > 0
  i -= 1
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
  q.push(q.pop)
end
```

ruby/prism@91f60cb736