reentrancy-benchmark-jruby.rb

require 'benchmark'
require 'thread'
require 'monitor'

mutex = Mutex.new
monitor = Monitor.new
nop = proc{}
range = 1..1_000_000

for j in 1..20
  puts "Warmup ##{j}/20"
  for i in range; mutex.synchronize   &nop end
  for i in range; monitor.synchronize &nop end
end
puts

Benchmark.bm(10) do |x|
  x.report('Mutex')  { for i in range; mutex.synchronize   &nop end }
  x.report('Monitor'){ for i in range; monitor.synchronize &nop end }
end

reentrancy-benchmark.rb

require 'benchmark'
require 'thread'
require 'monitor'

mutex = Mutex.new
monitor = Monitor.new
nop = proc{}
range = 1..1_000_000

Benchmark.bm(10) do |x|
  x.report('Mutex')  { for i in range; mutex.synchronize   &nop end }
  x.report('Monitor'){ for i in range; monitor.synchronize &nop end }
end

reentrancy-monitor.rb

require 'monitor'

m= Monitor.new
m.synchronize {
  m.synchronize {
    puts "Monitor is reentrant."
  }
}

reentrancy-mutex.rb

require 'thread'

m= Mutex.new
m.synchronize {
  m.synchronize {
    puts "Mutex is reentrant."
  }
}