Akatsuki reported ENV['TZ'] = 'UTC' improved 7x-8x faster on following code.
t = Time.now; 100000.times { Time.new(2019) }; Time.now - t
https://hackerslab.aktsk.jp/2019/12/01/141551
commit 4bc1669127(reduce tzset) dramatically improved this situation. But still,
TZ=UTC is faster than default.
This patch removs unnecessary tzset() call completely.
Performance check
----------------------
test program: t = Time.now; 100000.times { Time.new(2019) }; Time.now - t
before: 0.387sec
before(w/ TZ): 0.197sec
after: 0.162sec
after(w/ TZ): 0.165sec
OK. Now, Time creation 2x faster *and* TZ=UTC doesn't improve anything.
We can forget this hack completely. :)
Side note:
This patch slightly changes Time.new(t) behavior implicitly. Before this patch, it might changes
default timezone implicitly. But after this patch, it doesn't. You need to reset TZ
(I mean ENV['TZ'] = nil) explicitly.
But I don't think this is big impact. Don't try to change /etc/localtime on runtime.
Side note2: following test might be useful for testing "ENV['TZ'] = nil".
-----------------------------------------
% cat <<'End' | sudo sh -s
rm -f /etc/localtime-; cp -a /etc/localtime /etc/localtime-
rm /etc/localtime; ln -s /usr/share/zoneinfo/Asia/Tokyo /etc/localtime
./ruby -e '
p Time.new(2000).zone # JST
File.unlink("/etc/localtime"); File.symlink("/usr/share/zoneinfo/America/Los_Angeles", "/etc/localtime")
p Time.new(2000).zone # JST (ruby does not follow /etc/localtime modification automatically)
ENV["TZ"] = nil
p Time.new(2000).zone # PST (ruby detect /etc/localtime modification)
'
rm /etc/localtime; cp -a /etc/localtime- /etc/localtime; rm /etc/localtime-
End
These functions are used from within a compilation unit so we can
make them static, for better binary size. This changeset reduces
the size of generated ruby binary from 26,590,128 bytes to
26,584,472 bytes on my macihne.
This removes the related tests, and puts the related specs behind
version guards. This affects all code in lib, including some
libraries that may want to support older versions of Ruby.
This removes the security features added by $SAFE = 1, and warns for access
or modification of $SAFE from Ruby-level, as well as warning when calling
all public C functions related to $SAFE.
This modifies some internal functions that took a safe level argument
to no longer take the argument.
rb_require_safe now warns, rb_require_string has been added as a
version that takes a VALUE and does not warn.
One public C function that still takes a safe level argument and that
this doesn't warn for is rb_eval_cmd. We may want to consider
adding an alternative method that does not take a safe level argument,
and warn for rb_eval_cmd.
Looking at the list of symbols inside of libruby-static.a, I found
hundreds of functions that are defined, but used from nowhere.
There can be reasons for each of them (e.g. some functions are
specific to some platform, some are useful when debugging, etc).
However it seems the functions deleted here exist for no reason.
This changeset reduces the size of ruby binary from 26,671,456
bytes to 26,592,864 bytes on my machine.
This changes object_id from being based on the objects location in
memory (or a nearby memory location in the case of a conflict) to be
based on an always increasing number.
This number is a Ruby Integer which allows it to overflow the size of a
pointer without issue (very unlikely to happen in real programs
especially on 64-bit, but a nice guarantee).
This changes obj_to_id_tbl and id_to_obj_tbl to both be maps of Ruby
objects to Ruby objects (previously they were Ruby object to C integer)
which simplifies updating them after compaction as we can run them
through gc_update_table_refs.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
This changes object_id from being based on the objects location in
memory (or a nearby memory location in the case of a conflict) to be
based on an always increasing number.
This number is a Ruby Integer which allows it to overflow the size of a
pointer without issue (very unlikely to happen in real programs
especially on 64-bit, but a nice guarantee).
This changes obj_to_id_tbl and id_to_obj_tbl to both be maps of Ruby
objects to Ruby objects (previously they were Ruby object to C integer)
which simplifies updating them after compaction as we can run them
through gc_update_table_refs.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
* Stop making a redundant hash copy in Hash#dup
It was making a copy of the hash without rehashing, then created an
extra copy of the hash to do the rehashing. Since rehashing creates
a new copy already, this change just uses that rehashing to make
the copy.
[Bug #16121]
* Remove redundant Check_Type after to_hash
* Fix freeing and clearing destination hash in Hash#initialize_copy
The code was assuming the state of the destination hash based on the
source hash for clearing any existing table on it. If these don't match,
then that can cause the old table to be leaked. This can be seen by
compiling hash.c with `#define HASH_DEBUG 1` and running the following
script, which will crash from a debug assertion.
```ruby
h = 9.times.map { |i| [i, i] }.to_h
h.send(:initialize_copy, {})
```
* Remove dead code paths in rb_hash_initialize_copy
Given that `RHASH_ST_TABLE_P(h)` is defined as `(!RHASH_AR_TABLE_P(h))`
it shouldn't be possible for a hash to be neither of these, so there
is no need for the removed `else if` blocks.
* Share implementation between Hash#replace and Hash#initialize_copy
This also fixes key rehashing for small hashes backed by an array
table for Hash#replace. This used to be done consistently in ruby
2.5.x, but stopped being done for small arrays in ruby 2.6.x.
This also bring optimization improvements that were done for
Hash#initialize_copy to Hash#replace.
* Add the Hash#dup benchmark
This fixes instance_exec and similar methods. It also fixes
Enumerator::Yielder#yield, rb_yield_block, and a couple of cases
with Proc#{<<,>>}.
This support requires the addition of rb_yield_values_kw, similar to
rb_yield_values2, for passing the keyword flag.
Unlike earlier attempts at this, this does not modify the rb_block_call_func
type or add a separate function type. The functions of type
rb_block_call_func are called by Ruby with a separate VM frame, and we can
get the keyword flag information from the VM frame flags, so it doesn't need
to be passed as a function argument.
These changes require the following VM functions accept a keyword flag:
* vm_yield_with_cref
* vm_yield
* vm_yield_with_block
Previously, calling transform_values would call rb_hash_aset for each
key, needing to rehash it and look up its location.
Instead, we can use rb_hash_stlike_foreach_with_replace to replace the
values as we iterate without rehashing the keys.
Treat the ** syntax as passing a copy of the hash as the last
positional argument. If the hash being double splatted is empty, do
not add a positional argument.
Remove rb_no_keyword_hash, no longer needed.
After 5e86b005c0, I now think ANYARGS is
dangerous and should be extinct. This commit adds function prototypes
for rb_hash_foreach / st_foreach_safe. Also fixes some prototype
mismatches.
"hash_iter_lev" can be exported by Marshal.dump and it will
introduce inconsistency. To avoid this issue, use internal_id
instead of normal ID. This issue is pointed out by Chikanaga-san.
On ar_table, Do not keep a full-length hash value (FLHV, 8 bytes)
but keep a 1 byte hint from a FLHV (lowest byte of FLHV).
An ar_table only contains at least 8 entries, so hints consumes
8 bytes at most. We can store hints in RHash::ar_hint.
On 32bit CPU, we use 4 entries ar_table.
The advantages:
* We don't need to keep FLHV so ar_table only consumes
16 bytes (VALUEs of key and value) * 8 entries = 128 bytes.
* We don't need to scan ar_table, but only need to check hints
in many cases. Especially we don't need to access ar_table
if there is no match entries (in many cases).
It will increase memory cache locality.
The disadvantages:
* This technique can increase `#eql?` time because hints can
conflicts (in theory, it conflicts once in 256 times).
It can introduce incompatibility if there is a object x where
x.eql? returns true even if hash values are different.
I believe we don't need to care such irregular case.
* We need to re-calculate FLHV if we need to switch from ar_table
to st_table (e.g. exceeds 8 entries).
It also can introduce incompatibility, on mutating key objects.
I believe we don't need to care such irregular case too.
Add new debug counters to measure the performance:
* artable_hint_hit - hint is matched and eql?#=>true
* artable_hint_miss - hint is not matched but eql?#=>false
* artable_hint_notfound - lookup counts
iter_lev is used to detect the hash is iterating or not.
Usually, iter_lev should be very small number (1 or 2) so
`int` is overkill.
This patch introduce iter_lev in flags (7 bits, FL13 to FL19)
and if iter_lev exceeds this range, save it in hidden attribute.
We can get 1 word in RHash.
We can't modify frozen objects. Therefore I added new internal API
`rb_ivar_set_internal()` which allows us to set an attribute
even if the target object is frozen
if the name is hidden ivar (the name without `@` prefix).
The behavior of `Hash[[nil]] #=> {}` was a bug until 1.9.3, but had been
remained with a warning because some programs depended upon it.
Now, six years passed. We can remove the compatibility behavior.
[Bug #7300]
For example when an array containing objects is a hash key, the contents
of the array may move which can cause the hash value for the array to
change. This commit makes the default `hash` value based off the
object id, so the hash value will remain stable.
Fixes test/shell/test_command_processor.rb
For some reason symbols (or classes) are being overridden in trunk
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67598 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
KOSAKI Motohiro
Nobuyoshi Nakada
Kazuhiro NISHIYAMA
卜部昌平
Jeremy Evans
John Hawthorn
Aaron Patterson
Burdette Lamar
Yusuke Endoh
Dylan Thacker-Smith
Daniel Radetsky
Koichi Sasada
git
Koichi Sasada
Kenichi Kamiya
k0kubun
tenderlove