Add a quickie benchmarker.

FossilOrigin-Name: d29068edd8e72591d850c69b1454bd0b9567c0f10185be80aa1f8abaec618192

experiments/thread_usage.rb

@@ -0,0 +1,69 @@
+#!/usr/bin/env ruby
+#
+
+require 'mdbx'
+require 'benchmark'
+require 'fileutils'
+
+include FileUtils
+
+
+db = MDBX::Database.open( 'tmpdb' )
+mtx = Mutex.new
+
+at_exit do
+	rm_r 'tmpdb'
+end
+
+THREAD_COUNT = 10
+WRITES_PER   = 1000
+
+puts "#{THREAD_COUNT} simultaneous threads, #{WRITES_PER} writes each:"
+
+Benchmark.bm( 10 ) do |x|
+	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
+
+