ruby-mdbx/experiments/thread_usage.rb

#!/usr/bin/env ruby
#

require 'mdbx'
require 'benchmark'
require 'fileutils'

include FileUtils

at_exit do
	rm_r 'tmpdb'
end

THREAD_COUNT = 10
WRITES_PER   = 1000

puts "#{THREAD_COUNT} simultaneous threads, #{WRITES_PER} writes each:"

def run_bench( db, msg )
	mtx = Mutex.new
	Benchmark.bm( 10 ) do |x|
		puts msg
		puts '-' * 60

		x.report( " txn per write:" ) do
			threads = []
			THREAD_COUNT.times do |i|
				threads << Thread.new do
					mtx.synchronize do
						WRITES_PER.times do
							key = "%02d-%d" % [ i, rand(1000) ]
							db[ key ] = rand(1000)
						end
					end
				end
			end
			threads.map( &:join )
		end

		# Long running transactions require a mutex across threads.
		#
		x.report( "txn per thread:" ) do
			threads = []
			THREAD_COUNT.times do |i|
				threads << Thread.new do
					mtx.synchronize do
						db.transaction do
							WRITES_PER.times do
								key = "%02d-%d" % [ i, rand(1000) ]
								db[ key ] = rand(1000)
							end
						end
					end
				end
			end
			threads.map( &:join )
		end

		x.report( "    unthreaded:" ) do
			db.transaction do
				( THREAD_COUNT * WRITES_PER ).times do
					key = "000-%d" % [ rand(1000) ]
					db[ key ] = rand(1000)
				end
			end
		end
	end

	db.close
	puts
end


db = MDBX::Database.open( 'tmpdb' )
run_bench( db, "Default database flags:" )

db = MDBX::Database.open( 'tmpdb', no_metasync: true )
run_bench( db, "Disabled metasync:" )