Issue checkstyle#4370: Add multi thread mode to checkstyle launcher

config/import-control.xml

@@ -93,6 +93,7 @@
     <allow class="com.google.common.collect.ImmutableMap" local-only="true"/>
 
     <allow class="com.puppycrawl.tools.checkstyle.Checker" local-only="true"/>
+    <allow class="com.puppycrawl.tools.checkstyle.MultiThreadModeSettings" local-only="true"/>
     <!-- allowed till https://github.com/checkstyle/checkstyle/issues/3817 -->
     <allow pkg="com.puppycrawl.tools.checkstyle.utils"/>
   </subpackage>

pom.xml

@@ -1916,7 +1916,7 @@
             <configuration>
               <targetClasses>
                 <param>com.puppycrawl.tools.checkstyle.AuditEventDefaultFormatter</param>
-                <param>com.puppycrawl.tools.checkstyle.ConfigurationLoader</param>
+                <param>com.puppycrawl.tools.checkstyle.ConfigurationLoader*</param>
                 <param>com.puppycrawl.tools.checkstyle.PackageNamesLoader</param>
                 <param>com.puppycrawl.tools.checkstyle.DefaultConfiguration</param>
                 <param>com.puppycrawl.tools.checkstyle.DefaultContext</param>
@@ -1929,6 +1929,8 @@
                 <param>com.puppycrawl.tools.checkstyle.Checker</param>
                 <param>com.puppycrawl.tools.checkstyle.ant.*</param>
                 <param>com.puppycrawl.tools.checkstyle.doclets.*</param>
+                <param>com.puppycrawl.tools.checkstyle.MultiThreadModuleResolver</param>
+                <param>com.puppycrawl.tools.checkstyle.MultiThreadModeSettings</param>
               </targetClasses>
               <targetTests>
                 <param>com.puppycrawl.tools.checkstyle.AuditEventDefaultFormatterTest</param>
@@ -1944,6 +1946,8 @@
                 <param>com.puppycrawl.tools.checkstyle.CheckerTest</param>
                 <param>com.puppycrawl.tools.checkstyle.ant.*</param>
                 <param>com.puppycrawl.tools.checkstyle.doclets.*</param>
+                <param>com.puppycrawl.tools.checkstyle.MultiThreadModuleResolverTest</param>
+                <param>com.puppycrawl.tools.checkstyle.MultiThreadModeConfigurationTest</param>
               </targetTests>
               <excludedMethods>
                 <!-- till https://github.com/hcoles/pitest/issues/353 -->

src/it/java/com/google/checkstyle/test/base/BaseCheckTestSupport.java

@@ -44,6 +44,7 @@
 import com.puppycrawl.tools.checkstyle.Checker;
 import com.puppycrawl.tools.checkstyle.ConfigurationLoader;
 import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.MultiThreadModuleResolver;
 import com.puppycrawl.tools.checkstyle.PropertiesExpander;
 import com.puppycrawl.tools.checkstyle.TreeWalker;
 import com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter;
@@ -70,8 +71,10 @@ public class BaseCheckTestSupport {
      */
     protected static Configuration getConfiguration() throws CheckstyleException {
         if (configuration == null) {
+            final MultiThreadModuleResolver moduleResolver =
+                MultiThreadModuleResolver.singleThreadMode();
             configuration = ConfigurationLoader.loadConfiguration(XML_NAME, new PropertiesExpander(
-                    System.getProperties()));
+                    System.getProperties()), moduleResolver);
         }
 
         return configuration;

src/main/java/com/puppycrawl/tools/checkstyle/ConfigurationLoader.java

@@ -97,29 +97,41 @@ public final class ConfigurationLoader {
 
     /** Property resolver. **/
     private final PropertyResolver overridePropsResolver;
+
+    /** Module resolver. */
+    private final ModuleResolver moduleResolver;
+
     /** The loaded configurations. **/
     private final Deque<DefaultConfiguration> configStack = new ArrayDeque<>();
 
     /** Flags if modules with the severity 'ignore' should be omitted. */
     private final boolean omitIgnoredModules;
 
+    /** The multi thread mode configuration. */
+    private final MultiThreadModeSettings multiThreadModeSettings;
+
     /** The Configuration that is being built. */
     private Configuration configuration;
 
     /**
      * Creates a new {@code ConfigurationLoader} instance.
      * @param overrideProps resolver for overriding properties
+     * @param moduleResolver resolver for overriding module names
      * @param omitIgnoredModules {@code true} if ignored modules should be
      *         omitted
+     * @param multiThreadModeSettings the multi thread mode configuration
      * @throws ParserConfigurationException if an error occurs
      * @throws SAXException if an error occurs
      */
     private ConfigurationLoader(final PropertyResolver overrideProps,
-                                final boolean omitIgnoredModules)
+            final ModuleResolver moduleResolver, final boolean omitIgnoredModules,
+            final MultiThreadModeSettings multiThreadModeSettings)
             throws ParserConfigurationException, SAXException {
         saxHandler = new InternalLoader();
         overridePropsResolver = overrideProps;
         this.omitIgnoredModules = omitIgnoredModules;
+        this.multiThreadModeSettings = multiThreadModeSettings;
+        this.moduleResolver = moduleResolver;
     }
 
     /**
@@ -159,27 +171,96 @@ private void parseInputSource(InputSource source)
      */
     public static Configuration loadConfiguration(String config,
             PropertyResolver overridePropsResolver) throws CheckstyleException {
-        return loadConfiguration(config, overridePropsResolver, false);
+        return loadConfiguration(config, overridePropsResolver, null, false);
+    }
+
+    /**
+     * Returns the module configurations in a specified file.
+     * @param config location of config file, can be either a URL or a filename
+     * @param overridePropsResolver overriding properties
+     * @param moduleResolver overriding module
+     * @return the check configurations
+     * @throws CheckstyleException if an error occurs
+     */
+    public static Configuration loadConfiguration(String config,
+            PropertyResolver overridePropsResolver, ModuleResolver moduleResolver)
+            throws CheckstyleException {
+        return loadConfiguration(config, overridePropsResolver, moduleResolver, false);
+    }
+
+    /**
+     * Returns the module configurations in a specified file.
+     * @param config location of config file, can be either a URL or a filename
+     * @param overridePropsResolver overriding properties
+     * @param moduleResolver overriding properties
+     * @param multiThreadModeSettings the multi thread mode configuration
+     * @return the check configurations
+     * @throws CheckstyleException if an error occurs
+     */
+    public static Configuration loadConfiguration(String config,
+            PropertyResolver overridePropsResolver, ModuleResolver moduleResolver,
+            MultiThreadModeSettings multiThreadModeSettings) throws CheckstyleException {
+        return loadConfiguration(config, overridePropsResolver, moduleResolver,
+                false, multiThreadModeSettings);
+    }
+
+    /**
+     * Returns the module configurations in a specified file.
+     *
+     * @param config location of config file, can be either a URL or a filename
+     * @param overridePropsResolver overriding properties
+     * @param omitIgnoredModules {@code true} if modules with severity
+     *            'ignore' should be omitted, {@code false} otherwise
+     * @return the check configurations
+     * @throws CheckstyleException if an error occurs
+     */
+    public static Configuration loadConfiguration(String config,
+            PropertyResolver overridePropsResolver, boolean omitIgnoredModules)
+            throws CheckstyleException {
+        return loadConfiguration(config, overridePropsResolver,
+                MultiThreadModuleResolver.singleThreadMode(), omitIgnoredModules);
     }
 
     /**
      * Returns the module configurations in a specified file.
      *
      * @param config location of config file, can be either a URL or a filename
      * @param overridePropsResolver overriding properties
+     * @param moduleResolver overriding modules
      * @param omitIgnoredModules {@code true} if modules with severity
      *            'ignore' should be omitted, {@code false} otherwise
      * @return the check configurations
      * @throws CheckstyleException if an error occurs
      */
     public static Configuration loadConfiguration(String config,
-        PropertyResolver overridePropsResolver, boolean omitIgnoredModules)
+            PropertyResolver overridePropsResolver, ModuleResolver moduleResolver,
+            boolean omitIgnoredModules)
+            throws CheckstyleException {
+        return loadConfiguration(config, overridePropsResolver, moduleResolver,
+                omitIgnoredModules, MultiThreadModeSettings.getSingleThreadMode());
+    }
+
+    /**
+     * Returns the module configurations in a specified file.
+     *
+     * @param config location of config file, can be either a URL or a filename
+     * @param overridePropsResolver overriding properties
+     * @param moduleResolver overriding modules
+     * @param omitIgnoredModules {@code true} if modules with severity
+     *            'ignore' should be omitted, {@code false} otherwise
+     * @param multiThreadModeSettings the multi thread mode configuration
+     * @return the check configurations
+     * @throws CheckstyleException if an error occurs
+     */
+    public static Configuration loadConfiguration(String config,
+            PropertyResolver overridePropsResolver, ModuleResolver moduleResolver,
+            boolean omitIgnoredModules, MultiThreadModeSettings multiThreadModeSettings)
             throws CheckstyleException {
         // figure out if this is a File or a URL
         final URI uri = CommonUtils.getUriByFilename(config);
         final InputSource source = new InputSource(uri.toString());
-        return loadConfiguration(source, overridePropsResolver,
-                omitIgnoredModules);
+        return loadConfiguration(source, overridePropsResolver, moduleResolver,
+                omitIgnoredModules, multiThreadModeSettings);
     }
 
     /**
@@ -188,23 +269,25 @@ public static Configuration loadConfiguration(String config,
      *
      * @param configStream the input stream to the Checkstyle configuration
      * @param overridePropsResolver overriding properties
+     * @param moduleResolver overriding modules
      * @param omitIgnoredModules {@code true} if modules with severity
      *            'ignore' should be omitted, {@code false} otherwise
      * @return the check configurations
      * @throws CheckstyleException if an error occurs
      *
      * @deprecated As this method does not provide a valid system ID,
      *     preventing resolution of external entities, a
-     *     {@link #loadConfiguration(InputSource,PropertyResolver,boolean)
+     *     {@link #loadConfiguration(InputSource, PropertyResolver, ModuleResolver, boolean)
      *          version using an InputSource}
      *     should be used instead
      */
     @Deprecated
     public static Configuration loadConfiguration(InputStream configStream,
-        PropertyResolver overridePropsResolver, boolean omitIgnoredModules)
+            PropertyResolver overridePropsResolver, ModuleResolver moduleResolver,
+            boolean omitIgnoredModules)
             throws CheckstyleException {
-        return loadConfiguration(new InputSource(configStream),
-                                 overridePropsResolver, omitIgnoredModules);
+        return loadConfiguration(new InputSource(configStream), overridePropsResolver,
+                moduleResolver, omitIgnoredModules);
     }
 
     /**
@@ -214,18 +297,42 @@ public static Configuration loadConfiguration(InputStream configStream,
      *
      * @param configSource the input stream to the Checkstyle configuration
      * @param overridePropsResolver overriding properties
+     * @param moduleResolver overriding modules
      * @param omitIgnoredModules {@code true} if modules with severity
      *            'ignore' should be omitted, {@code false} otherwise
      * @return the check configurations
      * @throws CheckstyleException if an error occurs
      */
     public static Configuration loadConfiguration(InputSource configSource,
-            PropertyResolver overridePropsResolver, boolean omitIgnoredModules)
+            PropertyResolver overridePropsResolver, ModuleResolver moduleResolver,
+            boolean omitIgnoredModules)
+            throws CheckstyleException {
+        return loadConfiguration(configSource, overridePropsResolver, moduleResolver,
+                omitIgnoredModules, MultiThreadModeSettings.getSingleThreadMode());
+    }
+
+    /**
+     * Returns the module configurations from a specified input source.
+     * Note that if the source does wrap an open byte or character
+     * stream, clients are required to close that stream by themselves
+     *
+     * @param configSource the input stream to the Checkstyle configuration
+     * @param overridePropsResolver overriding properties
+     * @param moduleResolver resolver for overriding modules
+     * @param omitIgnoredModules {@code true} if modules with severity
+     *            'ignore' should be omitted, {@code false} otherwise
+     * @param multiThreadModeSettings the multi thread mode configuration
+     * @return the check configurations
+     * @throws CheckstyleException if an error occurs
+     */
+    public static Configuration loadConfiguration(InputSource configSource,
+        PropertyResolver overridePropsResolver, ModuleResolver moduleResolver,
+        boolean omitIgnoredModules, MultiThreadModeSettings multiThreadModeSettings)
             throws CheckstyleException {
         try {
             final ConfigurationLoader loader =
-                new ConfigurationLoader(overridePropsResolver,
-                                        omitIgnoredModules);
+                new ConfigurationLoader(overridePropsResolver, moduleResolver,
+                    omitIgnoredModules, multiThreadModeSettings);
             loader.parseInputSource(configSource);
             return loader.configuration;
         }
@@ -411,9 +518,16 @@ public void startElement(String uri,
                 throws SAXException {
             if (qName.equals(MODULE)) {
                 //create configuration
-                final String name = attributes.getValue(NAME);
+                final String originalName = attributes.getValue(NAME);
+                final String name;
+                if (moduleResolver == null) {
+                    name = originalName;
+                }
+                else {
+                    name = moduleResolver.resolveName(originalName);
+                }
                 final DefaultConfiguration conf =
-                    new DefaultConfiguration(name);
+                    new DefaultConfiguration(name, multiThreadModeSettings);
 
                 if (configuration == null) {
                     configuration = conf;

src/main/java/com/puppycrawl/tools/checkstyle/DefaultConfiguration.java

@@ -48,12 +48,26 @@ public final class DefaultConfiguration implements Configuration {
     /** The map containing custom messages. */
     private final Map<String, String> messages = new HashMap<>();
 
+    /** The multi thread mode configuration. */
+    private final MultiThreadModeSettings multiThreadModeSettings;
+
     /**
      * Instantiates a DefaultConfiguration.
      * @param name the name for this DefaultConfiguration.
      */
     public DefaultConfiguration(String name) {
+        this(name, MultiThreadModeSettings.getSingleThreadMode());
+    }
+
+    /**
+     * Instantiates a DefaultConfiguration.
+     * @param name the name for this DefaultConfiguration.
+     * @param multiThreadModeSettings the multi thread mode configuration.
+     */
+    public DefaultConfiguration(String name,
+        MultiThreadModeSettings multiThreadModeSettings) {
         this.name = name;
+        this.multiThreadModeSettings = multiThreadModeSettings;
     }
 
     @Override
@@ -131,4 +145,13 @@ public void addMessage(String key, String value) {
     public ImmutableMap<String, String> getMessages() {
         return ImmutableMap.copyOf(messages);
     }
+
+    /**
+     * Gets the multi thread mode configuration.
+     * @return the multi thread mode configuration.
+     */
+    @Override
+    public MultiThreadModeSettings getMultiThreadModeSettings() {
+        return multiThreadModeSettings;
+    }
 }