From: "José Ignacio" <joseignacio.fernandez@...>
Date: 2008-09-02T23:05:06+09:00
Subject: Re: Undo Object.extend

Benchmarks come to save us:

require 'benchmark'
module Mod; def method; 3*50+1; end; end
a = A.new; a.extend Mod
b = A.new; b.extend Mod
Benchmark.bm(30) do |x|
  x.report('Removing & extending (1)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (2)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (3)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (4)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (5)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (7)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (8)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (9)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('Removing & extending (10)') { 1000.times {b.remove(Mod); 
b.extend(Mod)} }
  x.report('a.method') { 5000000.times {a.method} }
  x.report('b.method') { 5000000.times {b.method} }
end

Output:
                                    user     system      total 
real
Removing & extending (1)        0.040000   0.000000   0.040000 ( 
0.044988)
Removing & extending (2)        0.090000   0.000000   0.090000 ( 
0.093711)
Removing & extending (3)        0.130000   0.000000   0.130000 ( 
0.132898)
Removing & extending (4)        0.170000   0.000000   0.170000 ( 
0.168743)
Removing & extending (5)        0.210000   0.000000   0.210000 ( 
0.214160)
Removing & extending (7)        0.260000   0.010000   0.270000 ( 
0.266014)
Removing & extending (8)        0.330000   0.000000   0.330000 ( 
0.327045)
Removing & extending (9)        0.400000   0.000000   0.400000 ( 
0.404618)
Removing & extending (10)       0.520000   0.000000   0.520000 ( 
0.519781)
a.method                        5.290000   1.140000   6.430000 ( 
6.428015)
b.method                        5.080000   1.130000   6.210000 ( 
6.390391)

It's suprising, but removing and extending slows down increasingly, 
though there is no slow down in the method call (i.e. a & b have the 
same performance).

I've tried to repeat the tests commenting out "super mod_clone" in 
Behaviourable.extend and now there's no slow down, so the performance 
issue is related with Object.extend.
-- 
Posted via http://www.ruby-forum.com/.