svn commit: r880843 - in /camel/trunk/camel-core/src/main/java/org/apache/camel/impl: DefaultCamelContext.java converter/DefaultTypeConverter.java

[davsclaus]

Author: davsclaus
Date: Mon Nov 16 16:53:08 2009
New Revision: 880843

URL: http://svn.apache.org/viewvc?rev=880843&view=rev
Log:
CAMEL-2177: Loading type converters is only done exctly once. Also WARN about 
overriding type converter fixed when a race condition occured.

Modified:
    
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
    
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/converter/DefaultTypeConverter.java

Modified: 
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
URL: 
http://svn.apache.org/viewvc/camel/trunk/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java?rev=880843&r1=880842&r2=880843&view=diff
==============================================================================
--- 
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
 (original)
+++ 
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/DefaultCamelContext.java
 Mon Nov 16 16:53:08 2009
@@ -671,7 +671,11 @@
 
     public TypeConverter getTypeConverter() {
         if (typeConverter == null) {
-            typeConverter = createTypeConverter();
+            synchronized (this) {
+                // we can synchronize on this as there is only one instance
+                // of the camel context (its the container)
+                typeConverter = createTypeConverter();
+            }
         }
         return typeConverter;
     }

Modified: 
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/converter/DefaultTypeConverter.java
URL: 
http://svn.apache.org/viewvc/camel/trunk/camel-core/src/main/java/org/apache/camel/impl/converter/DefaultTypeConverter.java?rev=880843&r1=880842&r2=880843&view=diff
==============================================================================
--- 
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/converter/DefaultTypeConverter.java
 (original)
+++ 
camel/trunk/camel-core/src/main/java/org/apache/camel/impl/converter/DefaultTypeConverter.java
 Mon Nov 16 16:53:08 2009
@@ -25,6 +25,7 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.apache.camel.CamelExecutionException;
 import org.apache.camel.Exchange;
@@ -41,7 +42,6 @@
 import org.apache.commons.logging.LogFactory;
 import static org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException;
 
-
 /**
  * Default implementation of a type converter registry used for
  * <a href="http://camel.apache.org/type-converter.html";>type converters</a> 
in Camel.
@@ -56,7 +56,7 @@
     private final List<TypeConverter> fallbackConverters = new 
ArrayList<TypeConverter>();
     private Injector injector;
     private final FactoryFinder factoryFinder;
-    private boolean loaded;
+    private AtomicBoolean loaded = new AtomicBoolean();
 
     public DefaultTypeConverter(PackageScanClassResolver resolver, Injector 
injector, FactoryFinder factoryFinder) {
         this.injector = injector;
@@ -212,10 +212,14 @@
         TypeMapping key = new TypeMapping(toType, fromType);
         synchronized (typeMappings) {
             TypeConverter converter = typeMappings.get(key);
-            if (converter != null) {
-                LOG.warn("Overriding type converter from: " + converter + " 
to: " + typeConverter);
+            // only override it if its different
+            // as race conditions can lead to many threads trying to promote 
the same fallback converter
+            if (typeConverter != converter) {
+                if (converter != null) {
+                    LOG.warn("Overriding type converter from: " + converter + 
" to: " + typeConverter);
+                }
+                typeMappings.put(key, typeConverter);
             }
-            typeMappings.put(key, typeConverter);
         }
     }
 
@@ -365,8 +369,11 @@
      * Checks if the registry is loaded and if not lazily load it
      */
     protected synchronized void checkLoaded() {
-        if (!loaded) {
-            loaded = true;
+        // must be synchronized to let other threads wait for it to initialize
+        // also use a atomic boolean so its state is visible for the other 
threads
+        // this ensure that at most one thread is loading all the type 
converters
+        if (loaded.compareAndSet(false, true)) {
+            LOG.debug("Loading type converters ...");
             try {
                 for (TypeConverterLoader typeConverterLoader : 
typeConverterLoaders) {
                     typeConverterLoader.load(this);
@@ -381,6 +388,7 @@
             } catch (Exception e) {
                 throw wrapRuntimeCamelException(e);
             }
+            LOG.debug("Loading type converters done");
         }
     }