Optimize class loading

In our project we found out that during the build up of the spring context
the class loading takes a very long time.
Root cause is the huge amount of file I/O during pointcut class loading.
We are taking about ~250k file loads.

With these changes we managed to cut down the starting time by around 50%.

What we found out is that IMHO - the clear method of the ClassLoaderRepository
is called far too often -> in our settings this resulted in not a single cache
hit as the cache got cleared permanently.
Therefore we de-actived the cache clear calls inside the ClassLoaderRepository.

Secondly we changed the Java15AnnotationFinder in a way to not always create
new objects for the ClassLoaderRepository but re-use one static instance.
Otherwise we experienced >100k objects being created.

Last but not least we introduced a cache for unavailable classes so that
they do not have to be looked up using file I/O over and over again.

The whole behavior is configurable via
+ org.aspectj.apache.bcel.useSingleRepositoryInstance (default: true)
+ org.aspectj.apache.bcel.useUnavailableClassesCache (default: true)
+ org.aspectj.apache.bcel.ignoreCacheClearRequests (default: true)

Signed-off-by: Stefan Starke <stefan@starkeweb.org>
Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

1 files changed, 39 insertions, 14 deletions

diff --git a/weaver/src/main/java/org/aspectj/weaver/reflect/Java15AnnotationFinder.java b/weaver/src/main/java/org/aspectj/weaver/reflect/Java15AnnotationFinder.java
index dfddd18da..ef437b724 100644
--- a/weaver/src/main/java/org/aspectj/weaver/reflect/Java15AnnotationFinder.java
+++ b/weaver/src/main/java/org/aspectj/weaver/reflect/Java15AnnotationFinder.java
@@ -42,9 +42,17 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 
 	private Repository bcelRepository;
 	private BcelWeakClassLoaderReference classLoaderRef;
+
+	private static Repository staticBcelRepository;
+	private static BcelWeakClassLoaderReference staticClassLoaderRef;
+
 	private World world;
 	private static boolean useCachingClassLoaderRepository;
 
+	//Use single instance of Repository and ClassLoader
+	public static final boolean useSingleInstances =
+		System.getProperty("org.aspectj.apache.bcel.useSingleRepositoryInstance", "true").equalsIgnoreCase("true");
+
 	static {
 		try {
 			useCachingClassLoaderRepository = System.getProperty("Xset:bcelRepositoryCaching","true").equalsIgnoreCase("true");
@@ -58,14 +66,31 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 	}
 
 	public void setClassLoader(ClassLoader aLoader) {
-		this.classLoaderRef = new BcelWeakClassLoaderReference(aLoader);
+		//Set class loader ref
+		if (useSingleInstances && staticClassLoaderRef == null)
+			staticClassLoaderRef = new BcelWeakClassLoaderReference(aLoader);
+		else
+			this.classLoaderRef = new BcelWeakClassLoaderReference(aLoader);
+
+		//Set repository
 		if (useCachingClassLoaderRepository) {
-			this.bcelRepository = new ClassLoaderRepository(classLoaderRef);
-		} else {
-			this.bcelRepository = new NonCachingClassLoaderRepository(classLoaderRef);
+			if (useSingleInstances && staticBcelRepository == null)
+				staticBcelRepository = new ClassLoaderRepository(getClassLoader());
+			else
+				this.bcelRepository = new ClassLoaderRepository(getClassLoader());
+		}
+		else {
+			if (useSingleInstances && staticBcelRepository == null)
+				staticBcelRepository = new NonCachingClassLoaderRepository(getClassLoader());
+			else
+				this.bcelRepository = new NonCachingClassLoaderRepository(getClassLoader());
 		}
 	}
 
+	private Repository getBcelRepository() {
+		return useSingleInstances ? staticBcelRepository : bcelRepository;
+	}
+
 	public void setWorld(World aWorld) {
 		this.world = aWorld;
 	}
@@ -112,7 +137,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 	}
 
 	private ClassLoader getClassLoader() {
-		return classLoaderRef.getClassLoader();
+		return useSingleInstances ? staticClassLoaderRef.getClassLoader() : classLoaderRef.getClassLoader();
 	}
 
 	public AnnotationAJ getAnnotationOfType(UnresolvedType ofType, Member onMember) {
@@ -145,7 +170,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 				anns = bcelField.getAnnotations();
 			}
 			// the answer is cached and we don't want to hold on to memory
-			bcelRepository.clear();
+			getBcelRepository().clear();
 			// OPTIMIZE make constant 0 size array for sharing
 			if (anns == null)
 				anns = AnnotationGen.NO_ANNOTATIONS;
@@ -164,7 +189,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 
 	public String getAnnotationDefaultValue(Member onMember) {
 		try {
-			JavaClass jc = bcelRepository.loadClass(onMember.getDeclaringClass());
+			JavaClass jc = getBcelRepository().loadClass(onMember.getDeclaringClass());
 			if (onMember instanceof Method) {
 				org.aspectj.apache.bcel.classfile.Method bcelMethod = jc.getMethod((Method) onMember);
 
@@ -200,7 +225,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 		// we can just use reflection.
 		if (!areRuntimeAnnotationsSufficient) {
 			try {
-				JavaClass jc = bcelRepository.loadClass(onMember.getDeclaringClass());
+				JavaClass jc = getBcelRepository().loadClass(onMember.getDeclaringClass());
 				org.aspectj.apache.bcel.classfile.annotation.AnnotationGen[] anns = null;
 				if (onMember instanceof Method) {
 					org.aspectj.apache.bcel.classfile.Method bcelMethod = jc.getMethod((Method) onMember);
@@ -215,7 +240,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 					anns = bcelField.getAnnotations();
 				}
 				// the answer is cached and we don't want to hold on to memory
-				bcelRepository.clear();
+				getBcelRepository().clear();
 				if (anns == null || anns.length == 0) {
 					return ResolvedType.NONE;
 				}
@@ -246,9 +271,9 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 		// annotations so we bail out to Bcel and then chuck away the JavaClass so that we
 		// don't hog memory.
 		try {
-			JavaClass jc = bcelRepository.loadClass(forClass);
+			JavaClass jc = getBcelRepository().loadClass(forClass);
 			org.aspectj.apache.bcel.classfile.annotation.AnnotationGen[] anns = jc.getAnnotations();
-			bcelRepository.clear();
+			getBcelRepository().clear();
 			if (anns == null) {
 				return ResolvedType.NONE;
 			} else {
@@ -276,7 +301,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 			return null;
 
 		try {
-			JavaClass jc = bcelRepository.loadClass(forMember.getDeclaringClass());
+			JavaClass jc = getBcelRepository().loadClass(forMember.getDeclaringClass());
 			LocalVariableTable lvt = null;
 			int numVars = 0;
 			if (forMember instanceof Method) {
@@ -320,7 +345,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 		// don't hog
 		// memory.
 		try {
-			JavaClass jc = bcelRepository.loadClass(onMember.getDeclaringClass());
+			JavaClass jc = getBcelRepository().loadClass(onMember.getDeclaringClass());
 			org.aspectj.apache.bcel.classfile.annotation.AnnotationGen[][] anns = null;
 			if (onMember instanceof Method) {
 				org.aspectj.apache.bcel.classfile.Method bcelMethod = jc.getMethod((Method) onMember);
@@ -340,7 +365,7 @@ public class Java15AnnotationFinder implements AnnotationFinder, ArgNameFinder {
 				// anns = null;
 			}
 			// the answer is cached and we don't want to hold on to memory
-			bcelRepository.clear();
+			getBcelRepository().clear();
 			if (anns == null)
 				return NO_PARAMETER_ANNOTATIONS;
 			ResolvedType[][] result = new ResolvedType[anns.length][];