Slide 1
Slide 1 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
What's New in Ruby 2.0
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 2
Slide 2 text
No content
Slide 3
Slide 3 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby 2 is CoMING!
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 4
Slide 4 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
/people/@me/@self
●
@shyouhei
●
Ruby Core Team
●
Ruby 1.8.{5,6,7}
release mgr. &
branch mentor
Slide 5
Slide 5 text
Delight and Impact the World
Slide 6
Slide 6 text
No content
Slide 7
Slide 7 text
No content
Slide 8
Slide 8 text
No content
Slide 9
Slide 9 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby 2.0.0 is coming
●
Ruby, version 2.0.0, is appearing in Feb. 24th,
2013. What's expected?
– More syntax
– More speed
– More feature
– … and maybe more!
Slide 10
Slide 10 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby is Growing
Slide 11
Slide 11 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
http://modulecounts.com
Slide 12
Slide 12 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby and “Good Parts”
“Ruby is designed to be fun.”
– Yukihiro Matsumoto
出典 : 「オブジェクト指向スクリプト言語 Ruby 」
Slide 13
Slide 13 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby and “Good Parts”
“I was socked. Ruby was the frst language
emphasized on our feeling.”
– Dr. Shinichiro Hara
http://www.nicovideo.jp/watch/sm6516554
Slide 14
Slide 14 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby and “Good Parts”
“The real paradigm shift is in the fact that Ruby
was designed to make programming fast,
enjoyable and easy instead of being optimized
for machines running it.”
– Matt Aimonetti
http://merbist.com/2009/11/16/the-ruby-revolution-take-ii/
Slide 15
Slide 15 text
No content
Slide 16
Slide 16 text
No content
Slide 17
Slide 17 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
What drives us
“I was delighted to refect on the thought that
they were right there in the values of Ward, Kent,
and all the other people who've been advocating
clean code, well-factored object-oriented design,
and testability. These ideas have made a great
impact on many other technological communi-
ties, but in Ruby-land they are the orthodoxy.”
– Martin Fowler
http://www.martinfowler.com/bliki/RailsConf2007.html
Slide 18
Slide 18 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
What drives us
“Ruby doesn't change your company. It is you
who are changed. You are to change the world.”
– Shunichi Arai
広島 Ruby 会議 01 での発言
Slide 19
Slide 19 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Change
Slide 20
Slide 20 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Why Ruby 2.0
●
Because we change things.
●
We are eager to make ourself more and more
happy, healthy, productive.
●
Don't be afraid. “Embrace the change.”
Slide 21
Slide 21 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
What's New in Ruby 2.0
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 22
Slide 22 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
What's NOT new in Ruby 2
●
Almost everything.
●
“100% backward compatible”, said matz.
– In reality …
●
(for instance) Rails runs as-is.
Slide 23
Slide 23 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
That being said,
●
New things are added
●
Also lots of internal improvements
Slide 24
Slide 24 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
New Syntax in Ruby 2.0
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 25
Slide 25 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Keyword arguments
●
Following code was already OK since 1.x.
●
So, what's the problem?
obj.method "with", :lots => "of",
:args => "in",
:hash => "form"
Slide 26
Slide 26 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Keyword arguments
●
The problem is on method definition:
def obj.method(arg, hash)
lots = Hash[:lots] || "default"
args = Hash[:args] || "another"
hand = Hash[:by hand] || "annoying"
…
end Hand-written code
== root cause of bugs
Slide 27
Slide 27 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Keyword arguments
●
Introducing keyword args (since 2.0):
●
This way, local variables “a”, “b”, “c”, and “d”
are all assigned.
●
Caller side doesn't change.
def obj.method(a, b = 1, c: 1, d: 2)
Positional Optional Keyworded
Keyworded
Slide 28
Slide 28 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Other minor syntactic updates
●
Symbol array literal %i and %I introduced.
●
Ruby now thinks its inputs to be UTF-8
encoded by default. You can of course specify
other encodings explicitly.
%i(foo bar baz) # => [:foo, :bar, :baz]
Slide 29
Slide 29 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby 2.0 improvements of
Core Performance
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 30
Slide 30 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
require improvements
●
Background: today as we have gems, booting
ruby up tends to require 128+ libraries at
once, resulting poor experience.
●
Solution: require got faster (in sense of com-
putational complexity).
– Several techniques to reduce computations.
Slide 31
Slide 31 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
require improvements
Slide 32
Slide 32 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Backtrace lazy generation
●
Since the beginning, backtraces has been
arrays of strings.
●
Each time an exception was raised, these
strings were generated from up to down, even
when that was not actually used.
– Can get ultra slow when you have 1024+ stack
frames (typical Rails situation).
Slide 33
Slide 33 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Backtrace lazy generation
●
Starting ruby 2.x, Thread::Backtrace are used
instead of strings.
– Which are very lightweight.
●
When you need to look at the backtrace, just
convert them to strings (call #to_s).
Slide 34
Slide 34 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Backtrace lazy generation
Slide 35
Slide 35 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Flonum introduced
●
On a 64bit machine (ubiquitous these days),
pointers, integers and foating-point numbers
are all 64bit width.
●
In ruby, pointers and integers are C level
register variables. But double was stored
on-memory. What if we can handle them like
pointers?
Slide 36
Slide 36 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Flonum introduced
fags
fags
klass
klass
double
double
(unused)
(unused)
(unused)
(unused)
double/ptr
double/ptr
struct
union
Slide 37
Slide 37 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Flonum introduced
●
Problem: how to union a pointer and a double?
MSB LSB
offset
PT
PD
PDP
PML4
(unused)
MSB LSB
fraction
exponent
sign
Slide 38
Slide 38 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Flonum introduced
●
Solution: some tricky bit-shifts
– Sasada, K., “A Lightweight Representation of
Floating-Point Numbers on Ruby Interpreter”, in
PPL2008.
Slide 39
Slide 39 text
Benchmark results
0
0.5
1
1.5
2
2.5
3
app_answer
app_factorial
app_pentomino
app_tak
io_file_create
io_select
loop_for
loop_whileloop
so_array
so_count_words
so_fasta
so_mandelbrot
so_nbody
so_nsieve_bits
so_pidigits
so_sieve
vm1_block*
vm1_float_calc*
vm1_length*
vm1_lvar_set*
vm1_rescue*
vm2_array*
vm2_case*
vm2_method*
vm2_poly_method_ov*
vm2_raise2*
vm2_super*
vm3_backtrace
vm3_thread_mutex
vm_thread_mutex1
vm_thread_pass
clean/flonum
clean/flonum.z
© benchmarked by @_ko1
Slide 40
Slide 40 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
GC things
●
Bitmap marking: GC mark bits were in every
objects, but moved into a dedicated memory
page to reduce cache misshits (also much
more CoW friendly).
●
Nonrecursive marking: mark function now
avoids the risk of machine stack overfow.
●
Lazy sweep (since 1.9.3): sweeper collects only
what's necessary (reduces stop time).
Slide 41
Slide 41 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby 2.0 New Core Features
#1 Instrumentations
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 42
Slide 42 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
DTrace support!
●
You can probe live production Ruby behaviour
in non-stop, non-overhead fashion.
●
Supports Solaris (dtrace), Mac OS X (dtrace),
and Linux (SystemTrap).
● http://bugs.ruby-lang.org/projects/ruby/wiki/DTraceProbes
Slide 43
Slide 43 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
DTrace support!
●
Mac example
MAC % sudo dtrace -q -n 'ruby$target:::find-require-entry {
printf("%s\n", copyinstr(arg0))
}' -c "ruby /var/apps/www/script/rails server"
Slide 44
Slide 44 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
TracePoint
●
DTrace is great, but not ruby-way. I want to
programmatically dynamically trace some
execution!
●
Then use TracePoint.
Slide 45
Slide 45 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
TracePoint
trace = TracePoint.new(:raise) do |tp|
p [tp.lineno, tp.event, tp.raised_exception]
end
#=> #
trace.enable
#=> #
0 / 0
#=> [5, :raise, #]
Slide 46
Slide 46 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
GC stats
●
GC.stat: live object counts
●
GC::Profiler(1.9+): GC timing profiler
GC.stat #=> {
count: 17,
heap_used: 79,
heap_length: 79,
heap_increment: 0,
heap_live_num: 22798,
heap_free_num: 18020,
heap_final_num: 0,
total_allocated_object: 82397,
total_freed_object: 59599,
}
Slide 47
Slide 47 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Ruby 2.0 New Core Features
#2 Core Libraries
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 48
Slide 48 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Fine-Grained Asynchronous Interrupt Handling
●
Background: ruby execution sometimes gets
interrupted for various reasons, e.g. timeout.
timeout(rand()) do
setup
handle
teardown
end
Complete Russian
Roulette on where
it gets interrupted!
Slide 49
Slide 49 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Fine-Grained Asynchronous Interrupt Handling
Thread.async_interrupt_timing Timeout::Error => :defer do
timeout(rand()) do
begin
Thread.async_interrupt_timing Timeout::Error => :immediate do
setup
handle
…
end
ensure
teardown
end
end
end
Slide 50
Slide 50 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Fine-Grained Asynchronous Interrupt Handling
Thread.async_interrupt_timing Timeout::Error => :defer do
timeout(rand()) do
begin
Thread.async_interrupt_timing Timeout::Error => :immediate do
setup
handle
…
end
ensure
teardown
end
end
end
Blue area gets
interrupted
Red area does not.
Slide 51
Slide 51 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Module Prepending
●
Sometimes you want to add setup / teardown
of a method defined elswhere.
module ActiveRecordHelper
def save
???
end
end
Wanna setup/teardown
but how do we do that?
Slide 52
Slide 52 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Module Prepending
module AR::Helper
def save
foo
super
baz
end
end
Foo.new.save
class Foo < AR::Base
prepend AR::Helper
def save
bar
end
end
Slide 53
Slide 53 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Module Prepending
●
This is how we solved Rails' “alias method
chain” situation. AMC is no longer needed.
Slide 54
Slide 54 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Lazy Enumerator
●
Ruby's foo.bar.baz. … style (so-called being
“fuent”) sometimes requires unnecessary
temporary object to pass around, which can
theoretically be avoided by lazy evaluations.
Slide 55
Slide 55 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Lazy Enumerator
File.open(path) {|fp|
fp.each_line. \
select {|line|
/regexp/ =~ line
}. \
each_with_index.map {|line, no|
sprintf("%d: %s\n", no, line)
}. \
first(10).each {|str|
puts(str)
}
}
Generates temporary array
Generates temporary array
Generates temporary array
Slide 56
Slide 56 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Lazy Enumerator
File.open(path) {|fp|
fp.each_line.lazy \
select {|line|
/regexp/ =~ line
}. \
each_with_index.map {|line, no|
sprintf("%d: %s\n", no, line)
}. \
first(10).each {|str|
puts(str)
}
}
No temporary array
No temporary array
No temporary array
Doesn't even read until EOF
Slide 57
Slide 57 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Lazy Enumerator
●
Interesting application: infinite enumerator
# Leibniz formula for π
(0..Float::INFINITY).lazy.map {|i|
((-1) ** i) / (2*i + 1).to_f
}.take(65536).reduce(:+) * 4
Slide 58
Slide 58 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Other new methods
●
Kernel.__dir__: directory name of __FILE__
●
Kernel#to_h: ubiquitous Hash conversion
●
Random class(1.9+): repeatable PRNG
●
IO#wait_writable: wait until it gets writable
●
Refinements: experimental.
Slide 59
Slide 59 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Standard Library updates
for Ruby 2.0
February 22nd, 2013.
URABE, Shyouhei.
PFSYS Dept., GPS Div.,
DeNA Co., Ltd.
Slide 60
Slide 60 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
CGI
●
CGI is now HTML5 ready.
Slide 61
Slide 61 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
net/http
●
Now supports SNI (Server Name Indication)
Slide 62
Slide 62 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Zlib binding
●
Zlib now runs out of the interpreter lock. This
means zlib runs faster than before on multi-
threaded situations.
Slide 63
Slide 63 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Updated stdlibs
●
Rubygems 2.0.0
●
JSON 1.7.7
●
Rake 0.9.5
●
Rdoc 4.0
●
And others (REXML, yaml, openssl, …)
Slide 64
Slide 64 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Conclusion
Slide 65
Slide 65 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
What's NOT new in Ruby 2
●
Almost everything.
●
“100% backward compatible”, said matz.
●
(for instance) Rails runs as-is.
●
Don't be afraid! Just start using 2.0.0!
Slide 66
Slide 66 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
That being said,
●
New things are added
●
Also lots of internal improvements
●
Even if you are already confident about your
current environment, 2.0.0 is worth looking at.
Slide 67
Slide 67 text
Copyright (C) 2013 DeNA Co.,Ltd. All Rights Reserved.
Use Ruby Today!