Mutex benchmarks

bm_lock.cr

require "benchmark"

i1 = 0_i64
m1 = Mutex.new

spawn do
  loop do
    m1.synchronize do
      i1 += 1
    end
  end
end

Benchmark.ips do |x|
  x.report("Mutex.synchronize") do
    m1.synchronize do
      i1 -= 1
    end
  end
end

test-mutex.cr

i = 0
m = Mutex.new
ch = Channel(Nil).new
n = ARGV[0].to_i

4.times do
  spawn do
    n.times do
      m.synchronize { i += 1 }
    end
    ch.send nil
  end
end

start = Time.local
4.times { ch.receive }
finish = Time.local

puts finish - start
puts i