GRAILS-6622 - Introduced ConcurrentLinkedHashMap to solve memory leak in DefaultUrlMappingsHolder.

Author: Marco Vermeulen

build.properties

@@ -29,6 +29,7 @@ bundlor.commons.fileupload.version=1.2.1
 bundlor.commons.io.version=1.4.0
 bundlor.commons.collections.version=3.2.1
 bundlor.commons.validator.version=1.3.1
+bundlor.concurrentlinkedhashmap.version=1.0
 
 grails.src=src/java
 grails.test=src/test

dependencies.txt

@@ -17,6 +17,11 @@ The following libraries are included in Grails because they are required either
 - CGLIB 2.1_3 with ObjectWeb ASM 1.5.3 (http://cglib.sourceforge.net) Apache 1.1 License
 - required for running Grails applications (Spring AOP & Hibernate)
 
+* clhm-release-1.0-lru.jar
+- ConcurrentLinkedHashMap policy: least-recently-used, jdk: 6 (https://code.google.com/p/concurrentlinkedhashmap) Apache License 2.0
+- required for building Grails core
+- required for running Grails applications
+
 * commons-beanutils-1.8.0.jar
 - Commons BeanUtils 1.8.0 (http://commons.apache.org/beanutils/) Apache 2.0 License
 - required for running Grails applications 

ivy.xml

@@ -34,6 +34,7 @@
 		<dependency org="antlr" name="antlr" rev="2.7.6"/>
 		<dependency org="jaxen" name="jaxen" rev="1.1-beta-11"/>				 							
 		<dependency org="bsf" name="bsf" rev="2.3.0"/>				 									
-		<dependency org="hibernate" name="hibernate" rev="3.2"/>	   
+		<dependency org="hibernate" name="hibernate" rev="3.2"/>	
+		<dependency org="com.googlecode.concurrentlinkedhashmap" name="concurrentlinkedhashmap-lru" rev="1.0"/>   
     </dependencies>
 </ivy-module>

lib/clhm-release-1.0-lru.jar

@@ -38,6 +38,8 @@ Import-Template:
   org.w3c.dom.*;version="0",
   org.xml.sax.*;version="0",
   org.xmlpull.v1.*;version="${xpp.version:[=.=.=, +1.0.0)}",
-  org.springframework.*;version="${spring.version:[=.=.=, +1.0.0)}"
+  org.springframework.*;version="${spring.version:[=.=.=, +1.0.0)}",
+  com.googlecode.concurrentlinkedhashmap.*;version="${concurrentlinkedhashmap.version:[=.=.=, +1.0)}"
+
 
 

maven/grails-web.mf

@@ -108,6 +108,12 @@
 
 <!-- Runtime Dependencies -->
 
+        <!-- ConcurrentLinkedHashmap used by DefaultUrlMappingsHolder -->
+        <dependency>
+            <groupId>com.googlecode.concurrentlinkedhashmap</groupId>
+            <artifactId>concurrentlinkedhashmap-lru</artifactId>
+            <version>1.0</version>
+        </dependency>
 
 
 <!-- Test Dependencies -->

maven/grails-web.pom.in

@@ -26,6 +26,10 @@ grails.mime.types = [ html: ['text/html','application/xhtml+xml'],
                       form: 'application/x-www-form-urlencoded',
                       multipartForm: 'multipart/form-data'
                     ]
+
+// URL Mapping Cache Max Size, defaults to 5000
+//grails.urlmapping.cache.maxsize = 1000
+
 // The default codec used to encode data with ${}
 grails.views.default.codec = "none" // none, html, base64
 grails.views.gsp.encoding = "UTF-8"

src/grails/grails-app/conf/Config.groovy

@@ -237,7 +237,8 @@ class IvyDependencyManager extends AbstractIvyDependencyManager implements Depen
                       "org.grails:grails-web:$grailsVersion",
                       "org.slf4j:slf4j-api:1.5.8",
                       "org.slf4j:slf4j-log4j12:1.5.8",
-                      "org.springframework:org.springframework.test:3.0.3.RELEASE"
+                      "org.springframework:org.springframework.test:3.0.3.RELEASE",
+                      "com.googlecode.concurrentlinkedhashmap:concurrentlinkedhashmap-lru:1.0"
 
                 docs   "org.xhtmlrenderer:core-renderer:R8",
                        "com.lowagie:itext:2.0.8",
@@ -257,6 +258,7 @@ class IvyDependencyManager extends AbstractIvyDependencyManager implements Depen
                 }
 
                 "${compileTimeDependenciesMethod}"("aopalliance:aopalliance:1.0",
+                        "com.googlecode.concurrentlinkedhashmap:concurrentlinkedhashmap-lru:1.0",
                         "commons-codec:commons-codec:1.3",
                         "commons-collections:commons-collections:3.2.1",
                         "commons-io:commons-io:1.4",

src/java/org/codehaus/groovy/grails/resolve/IvyDependencyManager.groovy

@@ -26,17 +26,18 @@
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
-import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.codehaus.groovy.grails.commons.GrailsControllerClass;
 import org.codehaus.groovy.grails.validation.ConstrainedProperty;
 import org.springframework.core.style.ToStringCreator;
 
+import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
+
 /**
  * Default implementation of the UrlMappingsHolder interface that takes a list of mappings and
- * then sorts them according to their precdence rules as defined in the implementation of Comparable.
+ * then sorts them according to their precedence rules as defined in the implementation of Comparable.
  *
  * @see org.codehaus.groovy.grails.web.mapping.UrlMapping
  * @see Comparable
@@ -48,9 +49,11 @@
 public class DefaultUrlMappingsHolder implements UrlMappingsHolder {
 
     private static final transient Log LOG = LogFactory.getLog(DefaultUrlMappingsHolder.class);
+    private static final int DEFAULT_MAX_WEIGHTED_CAPACITY = 5000;
 
-    private Map<String, UrlMappingInfo> cachedMatches = new ConcurrentHashMap<String, UrlMappingInfo>();
-    private Map<String, List<UrlMappingInfo>> cachedListMatches = new ConcurrentHashMap<String, List<UrlMappingInfo>>();
+    private int maxWeightedCacheCapacity;
+    private Map<String, UrlMappingInfo> cachedMatches;
+    private Map<String, List<UrlMappingInfo>> cachedListMatches;
 
     private List<UrlMapping> urlMappings = new ArrayList<UrlMapping>();
     private UrlMapping[] mappings;
@@ -68,18 +71,34 @@ public class DefaultUrlMappingsHolder implements UrlMappingsHolder {
 
     public DefaultUrlMappingsHolder(List<UrlMapping> mappings) {
         urlMappings = mappings;
+        this.maxWeightedCacheCapacity = DEFAULT_MAX_WEIGHTED_CAPACITY;
         initialize();
     }
 
     public DefaultUrlMappingsHolder(List<UrlMapping> mappings, List excludePatterns) {
         urlMappings = mappings;
         this.excludePatterns = excludePatterns;
+        this.maxWeightedCacheCapacity = DEFAULT_MAX_WEIGHTED_CAPACITY;
         initialize();
     }
-
+    
+    public DefaultUrlMappingsHolder(List<UrlMapping> mappings, List excludePatterns, int maxWeightedUrlCacheSize){
+        urlMappings = mappings;
+        this.excludePatterns = excludePatterns;
+        this.maxWeightedCacheCapacity = maxWeightedUrlCacheSize;
+        initialize();
+    }
+    
     private void initialize() {
         sortMappings();
 
+        cachedMatches = new ConcurrentLinkedHashMap.Builder<String, UrlMappingInfo>()
+            .maximumWeightedCapacity(maxWeightedCacheCapacity)
+            .build();
+        cachedListMatches = new ConcurrentLinkedHashMap.Builder<String, List<UrlMappingInfo>>()
+            .maximumWeightedCapacity(maxWeightedCacheCapacity)
+            .build();
+        
         mappings = urlMappings.toArray(new UrlMapping[urlMappings.size()]);
 
         for (UrlMapping mapping : mappings) {
@@ -346,12 +365,13 @@ public String toString() {
     /**
      * A class used as a key to lookup a UrlMapping based on controller, action and parameter names
      */
+    @SuppressWarnings("unchecked")
     class UrlMappingKey implements Comparable {
         String controller;
         String action;
-        Set paramNames = Collections.EMPTY_SET;
+        Set<String> paramNames = Collections.EMPTY_SET;
 
-        public UrlMappingKey(String controller, String action, Set paramNames) {
+        public UrlMappingKey(String controller, String action, Set<String> paramNames) {
             this.controller = controller;
             this.action = action;
             this.paramNames = paramNames;

src/java/org/codehaus/groovy/grails/web/mapping/DefaultUrlMappingsHolder.java

@@ -18,6 +18,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Properties;
 
 import javax.servlet.ServletContext;
 
@@ -39,7 +40,7 @@
  * @since 0.5
  */
 public class UrlMappingsHolderFactoryBean implements FactoryBean<UrlMappingsHolder>, InitializingBean, GrailsApplicationAware, ServletContextAware {
-
+    private static final String URL_MAPPING_CACHE_MAX_SIZE = "grails.urlmapping.cache.maxsize";
     private GrailsApplication grailsApplication;
     private UrlMappingsHolder urlMappingsHolder;
     private UrlMappingEvaluator mappingEvaluator;
@@ -83,8 +84,16 @@ public void afterPropertiesSet() throws Exception {
                 excludePatterns.addAll(mappingClass.getExcludePatterns());
             }
         }
-
-        urlMappingsHolder = new DefaultUrlMappingsHolder(urlMappings, excludePatterns);
+        
+        Properties props = grailsApplication.getConfig().toProperties();
+        String maxUrlCacheSize = props.getProperty(URL_MAPPING_CACHE_MAX_SIZE);
+        if(maxUrlCacheSize == null){
+            urlMappingsHolder = new DefaultUrlMappingsHolder(urlMappings, excludePatterns);
+        
+        } else {
+            int cacheSize = Integer.valueOf(maxUrlCacheSize);
+            urlMappingsHolder = new DefaultUrlMappingsHolder(urlMappings, excludePatterns, cacheSize);
+        }
     }
 
     public void setGrailsApplication(GrailsApplication grailsApplication) {