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Alex, here is the basic patch that is working well before you leave for the weekend ;-) I'll let Matthew post it officially to bugzilla since it was his idea. The earlier return from !enabled is a small addition I made that seems to help further. It would be great to have this in HEAD so I can report performance numbers based on it in part 2 of my article on developerworks ;-) Hope you are enjoying your new addition! Thanks! Index: ClassLoaderWeavingAdaptor.java =================================================================== RCS file: /home/technology/org.aspectj/modules/loadtime/src/org/aspectj/weaver/loadtim e/ClassLoaderWeavingAdaptor.java,v retrieving revision 1.18 diff -u -r1.18 ClassLoaderWeavingAdaptor.java --- ClassLoaderWeavingAdaptor.java 19 Oct 2005 13:11:36 -0000 1.18 +++ ClassLoaderWeavingAdaptor.java 21 Oct 2005 16:04:41 -0000 @@ -107,8 +107,13 @@ // register the definitions registerDefinitions(weaver, loader); + if (!enabled) { + return; + } messageHandler = bcelWorld.getMessageHandler(); + bcelWorld.setResolutionLoader((ClassLoader)null);//loader.getParent()); + // after adding aspects weaver.prepareForWeave(); } @@ -148,7 +153,11 @@ definitions.add(DocumentParser.parse(xml)); } } - + if (definitions.isEmpty()) { + enabled = false; + return; + } + // still go thru if definitions is empty since we will configure // the default message handler in there registerOptions(weaver, loader, definitions);
commited this one (TomcatGlassBox startup 28s -> 21s) please attach next for World sharing on java.* things
RC1
*** Bug 112817 has been marked as a duplicate of this bug. ***
using P2 to track things for RC1 (P3 or below will not make the cut...)
The reflection delegates code is now requiring a special type of world, a ReflectionWorld, which causes my previously working optimization that used reflection delegates when loading bootstrap classes to fail. This will also cause problems with any attempt to use reflection-based proxies to optimize instead of using BCEL proxies... In ReflectionBasedReferenceTypeDelegate this method fails now: protected ReflectionWorld getReflectionWorld() { return (ReflectionWorld) this.world; } My changed code that supported this is in BcelWorld. I think Matthew's right that it is going to be better to replace BCEL delegates with reflection-based proxies by weaving into classloaders. However, either way, I think it's going to be important to support reflection-based proxies for load-time weaving. protected ReferenceTypeDelegate resolveDelegate(ReferenceType ty) { String name = ty.getName(); JavaClass jc = null; if (hasResolutionLoader) { try { String asRes = name.replace ('.', '/').concat(".class"); // will I resolve this by delegating to my parent? java.net.URL parentURL = parent.getResource(asRes); if (parentURL != null && parentURL.equals(resolutionLoader.getResource(asRes))) { Class resultBoot = Class.forName (name, false, parent); if (resultBoot != null) { return new ReflectionBasedReferenceTypeDelegate(resultBoot, this, ty); } } Class resultBoot = Class.forName(name, false, null); if (resultBoot != null) { return new ReflectionBasedReferenceTypeDelegate(resultBoot, this, ty); } } catch (Throwable e) { // proceed with normal } }
Notes from a conversation with Adrian 10/11/05 We need to reduce startup time and latent foot print. There are 3 things we can do: 1. Only weave when we need to. We have already identified the “enbled” flag as a way to avoid using a weaver when no aop.xml is present. This could be extended to include situations where no aspects are actually declared or defined. 2. Use reflection instead of byte-code when it is safe to do so. We can introduce a new LTW World & Weaver which is constructed with a class loader and uses both BCEL/byte-code as well as reflection to resolve types. 3. Replace byte-code when we are certain that a class has been successfully defined. Woven byte-code must be retained in memory because it is difficult and expensive to recreate. However once a class has been defined the byte-code can be replaced by the Class object. There are 3 levels of optimization possible: a. Intercept successful calls to defineClass(), either though custom class loaders or weaving, and call back into the weaver. b. Cascade define events from parent loaders for types used in resolution but not defined locally c. Use weak references to allow the ResolvedMembers associated with a delegate to be dropped and further reduce latent footprint. Certain environments make these optimizations difficult. It is not possible to share resources reliably between weaver worlds because the relationship between the class loaders with which they are associated cannot always be determined e.g. OSGi. Using reflection may only be safe when using the boot loader due to non-delegating web application class loaders. Byte-code must continue to be used for aspects as their meta-data is not available through reflection pre-Java 5. However they will represent a small proportion of types in the system and a hybrid delegate could be introduced used where reflection is used for Java meta-data and byte-code for AspectJ meta-data. Many of these enhancements will be targeted post 1.5.0 therefore I suggest closing this bug as resolved because it addresses the simple enhancement to use the enabled flag. We should raise a separate enhancement for each possible optimization (I have already opened bug 114083 to cover an LTWWorld) to help stage their introduction and wider testing. Using this bug as a long running “bucket” will just be confusing.
Closing as per matthew's last comment. Ron :- note that the reflection world issue has been fixed under a separate bug report and your optimization should hopefully be working again now.
I updated bug #114083 with an improved optimization. Unfortunately, it isn't so simple to integrate even just the bootstrap loader performance improvement because it results in ClassCastExceptions from code like this: public static ResolvedMember createResolvedMethod(Method aMethod, World inWorld) { ReflectionBasedResolvedMemberImpl ret = new ReflectionBasedResolvedMemberImpl(org.aspectj.weaver.Member.METHOD, toResolvedType(aMethod.getDeclaringClass(),(ReflectionWorld)inWorld), aMethod.getModifiers(), toResolvedType(aMethod.getReturnType(),(ReflectionWorld)inWorld), Sample stack trace (from the debugger the method being resolved is public native int java.lang.Object.hashCode()): java.lang.ClassCastException: org.aspectj.weaver.ltw.LTWWorld at org.aspectj.weaver.reflect.ReflectionBasedReferenceTypeDelegateFactory.createResolvedMethod(ReflectionBasedReferenceTypeDelegateFactory.java:83) at org.aspectj.weaver.reflect.ReflectionBasedReferenceTypeDelegateFactory.createResolvedMember(ReflectionBasedReferenceTypeDelegateFactory.java:73) at org.aspectj.weaver.reflect.ReflectionBasedReferenceTypeDelegate.getDeclaredMethods(ReflectionBasedReferenceTypeDelegate.java:232) at org.aspectj.weaver.ReferenceType.getDeclaredMethods(ReferenceType.java:412) at org.aspectj.weaver.ResolvedType.getDeclaredAdvice(ResolvedType.java:682) at org.aspectj.weaver.ResolvedType.getDeclaredShadowMungers(ResolvedType.java:719) at org.aspectj.weaver.ResolvedType.collectShadowMungers(ResolvedType.java:559) at org.aspectj.weaver.ResolvedType.collectCrosscuttingMembers(ResolvedType.java:488) at org.aspectj.weaver.CrosscuttingMembersSet.addOrReplaceAspect(CrosscuttingMembersSet.java:58) at org.aspectj.weaver.bcel.BcelWeaver.addLibraryAspect(BcelWeaver.java:172) at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.registerAspects(ClassLoaderWeavingAdaptor.java:330) at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.registerDefinitions(ClassLoaderWeavingAdaptor.java:188) at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.initialize(ClassLoaderWeavingAdaptor.java:125) at org.aspectj.weaver.loadtime.Aj$ExplicitlyInitializedClassLoaderWeavingAdaptor.initialize(Aj.java:130) at org.aspectj.weaver.loadtime.Aj$ExplicitlyInitializedClassLoaderWeavingAdaptor.getWeavingAdaptor(Aj.java:135) at org.aspectj.weaver.loadtime.Aj$WeaverContainer.getWeaver(Aj.java:101) at org.aspectj.weaver.loadtime.Aj.preProcess(Aj.java:65)
