Add pool_concurrency_test manual spec

Add MT connection count without Mutex

spec/manual/pool_concurrency_test.cr

@@ -0,0 +1,68 @@
+# This file is to be executed as:
+#
+# % crystal run --release [-Dpreview_mt] ./spec/manual/pool_concurrency_test.cr -- --options="max_pool_size=5" --duration=30 --concurrency=4
+#
+#
+
+require "option_parser"
+require "../dummy_driver"
+require "../../src/db"
+
+options = ""
+duration = 3
+concurrency = 4
+
+OptionParser.parse do |parser|
+  parser.banner = "Usage: pool_concurrency_test [arguments]"
+  parser.on("-o", "--options=VALUE", "Connection string options") { |v| options = v }
+  parser.on("-d", "--duration=SECONDS", "Specifies the duration in seconds") { |v| duration = v.to_i }
+  parser.on("-c", "--concurrency=VALUE", "Specifies the concurrent requests to perform") { |v| concurrency = v.to_i }
+  parser.on("-h", "--help", "Show this help") do
+    puts parser
+    exit
+  end
+  parser.invalid_option do |flag|
+    STDERR.puts "ERROR: #{flag} is not a valid option."
+    STDERR.puts parser
+    exit(1)
+  end
+end
+
+multi_threaded = {% if flag?(:preview_mt) %} ENV["CRYSTAL_WORKERS"]?.try(&.to_i?) || 4 {% else %} false {% end %}
+release = {% if flag?(:release) %} true {% else %} false {% end %}
+
+if !release
+  puts "WARNING: This should be run in release mode."
+end
+
+db = DB.open "dummy://host?#{options}"
+
+start_time = Time.monotonic
+
+puts "Starting test for #{duration} seconds..."
+
+concurrency.times do
+  spawn do
+    loop do
+      db.scalar "1"
+      Fiber.yield
+    end
+  end
+end
+
+sleep duration.seconds
+
+end_time = Time.monotonic
+
+puts "          Options : #{options}"
+puts "   Duration (sec) : #{duration} (actual #{end_time - start_time})"
+puts "      Concurrency : #{concurrency}"
+puts "   Multi Threaded : #{multi_threaded ? "Yes (#{multi_threaded})" : "No"}"
+puts "Total Connections : #{DummyDriver::DummyConnection.connections_count}"
+puts " Total Statements : #{DummyDriver::DummyStatement.statements_count}"
+puts "    Total Queries : #{DummyDriver::DummyStatement.statements_exec_count}"
+puts "Throughtput (q/s) : #{DummyDriver::DummyStatement.statements_exec_count / duration}"
+
+if !release
+  puts "WARNING: This should be run in release mode."
+end