diff options
| -rw-r--r-- | loadtime/src/org/aspectj/weaver/loadtime/Aj.java | 148 |
1 files changed, 128 insertions, 20 deletions
diff --git a/loadtime/src/org/aspectj/weaver/loadtime/Aj.java b/loadtime/src/org/aspectj/weaver/loadtime/Aj.java index 4884d9eaa..131c13cf0 100644 --- a/loadtime/src/org/aspectj/weaver/loadtime/Aj.java +++ b/loadtime/src/org/aspectj/weaver/loadtime/Aj.java @@ -11,8 +11,13 @@ *******************************************************************************/ package org.aspectj.weaver.loadtime; +import java.lang.ref.ReferenceQueue; +import java.lang.ref.WeakReference; +import java.util.Collections; +import java.util.HashMap; +import java.util.Iterator; import java.util.Map; -import java.util.WeakHashMap; +import java.util.Set; import org.aspectj.bridge.context.CompilationAndWeavingContext; import org.aspectj.weaver.Dump; @@ -29,7 +34,14 @@ import org.aspectj.weaver.tools.WeavingAdaptor; public class Aj implements ClassPreProcessor { private IWeavingContext weavingContext; - + + /** + * References are added to this queue when their associated classloader is removed, and once on here that indicates + * that we should tidy up the adaptor map and remove the adaptor (weaver) from the map we are maintaining from + * adaptorkey > adaptor (weaver) + */ + private static ReferenceQueue adaptorQueue = new ReferenceQueue(); + private static Trace trace = TraceFactory.getTraceFactory().getTrace(Aj.class); public Aj(){ @@ -96,19 +108,127 @@ public class Aj implements ClassPreProcessor { } /** + * An AdaptorKey is a WeakReference wrapping a classloader reference that will enqueue to a specified queue when the + * classloader is GC'd. Since the AdaptorKey is used as a key into a hashmap we need to give it a non-varying + * hashcode/equals implementation, and we need that hashcode not to vary even when the internal referent has been + * GC'd. The hashcode is calculated on creation of the AdaptorKey based on the loader instance that it is wrapping. + * This means even when the referent is gone we can still use the AdaptorKey and it will 'point' to the same place + * as it always did. + */ + private static class AdaptorKey extends WeakReference { + + private int hashcode = -1; + + public AdaptorKey(ClassLoader loader) { + super(loader, adaptorQueue); + hashcode = loader.hashCode() * 37; + } + + public ClassLoader getClassLoader() { + ClassLoader instance = (ClassLoader) get(); + // Assert instance!=null - shouldn't be asked for after a GC of the referent has occurred ! + return instance; + } + + public boolean equals(Object obj) { + if (!(obj instanceof AdaptorKey)) return false; + AdaptorKey other = (AdaptorKey) obj; + return other.hashcode == hashcode; + } + + public int hashCode() { + return hashcode; + } + + } + + /** + * The reference queue is only processed when a request is made for a weaver adaptor. This means there can be one or + * two stale weavers left around. If the user knows they have finished all their weaving, they might wish to call + * removeStaleAdaptors which will process anything left on the reference queue containing adaptorKeys for garbage + * collected classloaders. + * + * @param displayProgress produce System.err info on the tidying up process + * @return number of stale weavers removed + */ + public static int removeStaleAdaptors(boolean displayProgress) { + int removed = 0; + synchronized (WeaverContainer.weavingAdaptors) { + if (displayProgress) { + System.err.println("Weaver adaptors before queue processing:"); + Map m = WeaverContainer.weavingAdaptors; + Set keys = m.keySet(); + for (Iterator iterator = keys.iterator(); iterator.hasNext();) { + Object object = (Object) iterator.next(); + System.err.println(object + " = " + WeaverContainer.weavingAdaptors.get(object)); + } + } + Object o = adaptorQueue.poll(); + while (o != null) { + if (displayProgress) System.err.println("Processing referencequeue entry " + o); + AdaptorKey wo = (AdaptorKey) o; + boolean didit = WeaverContainer.weavingAdaptors.remove(wo) != null; + if (didit) { + removed++; + } else { + throw new RuntimeException("Eh?? key="+wo); + } + if (displayProgress) System.err.println("Removed? "+didit); + o = adaptorQueue.poll(); + } + if (displayProgress) { + System.err.println("Weaver adaptors after queue processing:"); + Map m = WeaverContainer.weavingAdaptors; + Set keys = m.keySet(); + for (Iterator iterator = keys.iterator(); iterator.hasNext();) { + Object object = (Object) iterator.next(); + System.err.println(object + " = " + WeaverContainer.weavingAdaptors.get(object)); + } + } + } + return removed; + } + + /** + * @return the number of entries still in the weavingAdaptors map + */ + public static int getActiveAdaptorCount() { + return WeaverContainer.weavingAdaptors.size(); + } + + /** + * Process the reference queue that contains stale AdaptorKeys - the keys are put on the queue when their + * classloader referent is garbage collected and so the associated adaptor (weaver) should be removed from the map + */ + public static void checkQ() { + synchronized (adaptorQueue) { + Object o = adaptorQueue.poll(); + while (o != null) { + AdaptorKey wo = (AdaptorKey) o; + boolean removed = WeaverContainer.weavingAdaptors.remove(wo) != null; + // DBG System.err.println("Evicting key " + wo + " = " + didit); + o = adaptorQueue.poll(); + } + } + } + + /** * Cache of weaver * There is one weaver per classloader */ static class WeaverContainer { - private final static Map weavingAdaptors = new WeakHashMap(); + final static Map weavingAdaptors = Collections.synchronizedMap(new HashMap()); static WeavingAdaptor getWeaver(ClassLoader loader, IWeavingContext weavingContext) { ExplicitlyInitializedClassLoaderWeavingAdaptor adaptor = null; - synchronized(weavingAdaptors) { - adaptor = (ExplicitlyInitializedClassLoaderWeavingAdaptor) weavingAdaptors.get(loader); + AdaptorKey adaptorKey = new AdaptorKey(loader); + + synchronized (weavingAdaptors) { + checkQ(); + adaptor = (ExplicitlyInitializedClassLoaderWeavingAdaptor) weavingAdaptors.get(adaptorKey); if (adaptor == null) { - String loaderClassName = loader.getClass().getName(); + String loaderClassName = loader.getClass().getName(); if (loaderClassName.equals("sun.reflect.DelegatingClassLoader")) { // we don't weave reflection generated types at all! return null; @@ -117,25 +237,13 @@ public class Aj implements ClassPreProcessor { // within the synchronized block ClassLoaderWeavingAdaptor weavingAdaptor = new ClassLoaderWeavingAdaptor(); adaptor = new ExplicitlyInitializedClassLoaderWeavingAdaptor(weavingAdaptor); - weavingAdaptors.put(loader, adaptor); - } + weavingAdaptors.put(adaptorKey, adaptor); + } } } // perform the initialization return adaptor.getWeavingAdaptor(loader, weavingContext); - - // old version -// synchronized(loader) {//FIXME AV - temp fix for #99861 -// synchronized (weavingAdaptors) { -// WeavingAdaptor weavingAdaptor = (WeavingAdaptor) weavingAdaptors.get(loader); -// if (weavingAdaptor == null) { -// weavingAdaptor = new ClassLoaderWeavingAdaptor(loader, weavingContext); -// weavingAdaptors.put(loader, weavingAdaptor); -// } -// return weavingAdaptor; -// } -// } } } |