tester.rb in grntest-1.6.1

- old
+ new

@@ -197,11 +197,12 @@
                   "This option can be used multiple times") do |name|
           tester.exclude_test_suite_patterns << parse_name_or_pattern(name)
         end
 
         parser.on("--n-workers=N", Integer,
-                  "Use N workers to run tests") do |n|
+                  "Use N workers to run tests",
+                  "(#{tester.n_workers})") do |n|
           tester.n_workers = n
         end
 
         parser.on("--gdb[=COMMAND]",
                   "Run Groonga on gdb and use COMMAND as gdb",
@@ -380,11 +381,11 @@
       @output_type = "json"
       @testee = "groonga"
       @base_directory = Pathname(".")
       @database_path = nil
       @reporter = nil
-      @n_workers = 1
+      @n_workers = guess_n_cores
       @output = $stdout
       @keep_database = false
       @use_color = nil
       @stop_on_failure = false
       @suppress_omit_log = true
@@ -540,9 +541,31 @@
     end
 
     def run_test_suites(test_suites)
       runner = TestSuitesRunner.new(self)
       runner.run(test_suites)
+    end
+
+    def guess_n_cores
+      begin
+        if command_exist?("nproc")
+          # Linux
+          Integer(`nproc`.strip, 10)
+        elsif command_exist?("sysctl")
+          # macOS
+          Integer(`sysctl -n hw.logicalcpu`.strip, 10)
+        else
+          # Windows
+          value = ENV["NUMBER_OF_PROCESSORS"]
+          if value
+            Integer(value, 10)
+          else
+            1
+          end
+        end
+      rescue ArgumentError
+        1
+      end
     end
 
     def detect_suitable_diff
       if command_exist?("cut-diff")
         @diff = "cut-diff"