performance comparison of basic volatile updates

result.md

Test run using:

• JRuby 1.7.20
• Java 1.8.0_45
• OSX 10.10.3
• MBP 13r 2.8 GHz Intel Core i7

Calculating -------------------------------------
         synchronize   190.964k i/100ms
                lock   198.430k i/100ms
              atomic   197.997k i/100ms
              direct   278.351k i/100ms
-------------------------------------------------
         synchronize      4.635M (± 5.9%) i/s -    138.449M
                lock      5.402M (± 5.9%) i/s -    161.522M
              atomic      5.464M (± 5.8%) i/s -    163.348M
              direct     15.324M (± 8.1%) i/s -    456.217M

Comparison:
              direct: 15324498.3 i/s
              atomic:  5463820.7 i/s - 2.80x slower
                lock:  5401972.6 i/s - 2.84x slower
         synchronize:  4634833.2 i/s - 3.31x slower

volatile.rb

require "bundler/setup"
require "benchmark/ips"
require "concurrent_ruby"


@data = true
@mutex = Mutex.new
@atomic = Concurrent::AtomicBoolean.new(true)


def mutex_synchronize
  @mutex.synchronize{@data}
end

def mutex_lock
  @mutex.lock
  @data
ensure
  @mutex.unlock
end

def atomic
  @atomic.value
end

def direct
  @data
end

Benchmark.ips do |x|
  x.warmup = 30
  x.time = 30

  mutex = Mutex.new
  data = true

  x.report("synchronize") do
    mutex_synchronize
  end

  x.report("lock") do
    mutex_lock
  end

  x.report("atomic") do
    atomic
  end

  x.report("direct") do
    direct
  end

  x.compare!
end