Add GC profiling for ruby 1.9.

Author: metaskills

test/profile/gc_profile_case.rb

@@ -0,0 +1,68 @@
+require 'benchmark'
+require 'cases/sqlserver_helper'
+require 'models/topic'
+require 'models/reply'
+
+raise "GC allocation benchmarks only supported on Ruby 1.9!" unless RUBY_VERSION >= '1.9'
+
+class GcProfileCase < ActiveRecord::TestCase
+  
+  fixtures :topics
+  
+  def setup
+    create_mass_topics unless @created_mass_topics
+    @connection = ActiveRecord::Base.connection
+    @select_statement = "SELECT [topics].* FROM [topics]"
+  end
+  
+  def test_coercion
+    bench_allocations('coercion') do
+      Topic.all(:limit => 100).each do |t|
+        t.attributes.keys.each do |k|
+          t.send(k.to_sym)
+        end
+      end
+    end
+  end
+  
+  def test_select
+    bench_allocations('select') do
+      @connection.send :select, @select_statement
+    end
+  end
+  
+  def test_select_one
+    bench_allocations('select_one') do
+      100.times { @connection.select_one(@select_statement) }
+    end
+  end
+  
+  
+  protected
+  
+  def create_mass_topics
+    GC::Profiler.clear
+    GC::Profiler.disable
+    all_topics = Topic.all
+    100.times { all_topics.each { |t| Topic.create! t.attributes } }
+    @created_mass_topics = true
+    GC.start
+    GC::Profiler.enable
+    GC::Profiler.clear
+  end
+  
+  def bench_allocations(feature, iterations=10, &blk)
+    puts "\nGC overhead for #{feature}"
+    GC::Profiler.clear
+    GC::Profiler.enable
+    iterations.times{ blk.call }
+    GC::Profiler.report(STDOUT)
+    GC::Profiler.disable
+  end
+  
+end
+
+
+
+
+