Enable early lookup of Lambda and LambdaForm classes in the SCC

This patch adds:
- a unique ID to the generated Lambda and LambdaForm class names
- MethodHandleNatives functions for checking if a Lambda or LambdaForm
class is in the SCC based on the unique ID
- early SCC-lookup for both Lambda and LambdaForm classes

Signed-off-by: Nathan Henderson [email protected]

Author: ThanHenderson

src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java

@@ -23,6 +23,12 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2024, 2024 All Rights Reserved
+ * ===========================================================================
+ */
+
 package java.lang.invoke;
 
 import jdk.internal.org.objectweb.asm.*;
@@ -163,7 +169,29 @@ public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
         implMethodName = implInfo.getName();
         implMethodDesc = implInfo.getMethodType().toMethodDescriptorString();
         constructorType = invokedType.changeReturnType(Void.TYPE);
-        lambdaClassName = targetClass.getName().replace('.', '/') + "$$Lambda$" + counter.incrementAndGet();
+        String rawUniqueID = targetClass.getName()
+                        + invokedType.toString()
+                        + samMethodName
+                        + samMethodType.toString()
+                        + instantiatedMethodType.toString()
+                        + implMethodClassName
+                        + implMethodName
+                        + implMethodDesc;
+        StringBuilder encodedUniqueID = new StringBuilder();
+        String parentheses = "(){}[]<>";
+        for (int i = 0; i < rawUniqueID.length(); i++) {
+            char currentChar = rawUniqueID.charAt(i);
+            if (Character.isLetterOrDigit(currentChar)) {
+                encodedUniqueID.append(currentChar);
+            } else {
+                if (parentheses.indexOf(currentChar) != -1) {
+                    encodedUniqueID.append("__");
+                } else {
+                    encodedUniqueID.append('_');
+                }
+            }
+        }
+        lambdaClassName = targetClass.getName().replace('.', '/') + "$$Lambda$" + encodedUniqueID.toString();
         cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
         int parameterCount = invokedType.parameterCount();
         if (parameterCount > 0) {
@@ -252,6 +280,10 @@ public Constructor<?>[] run() {
      * is not found
      */
     private Class<?> spinInnerClass() throws LambdaConversionException {
+        Class<?> innerClass = MethodHandleNatives.findLambdaInSCC(lambdaClassName, targetClass);
+        if (innerClass != null) {
+            return innerClass;
+        }
         String[] interfaces;
         String samIntf = samBase.getName().replace('.', '/');
         boolean accidentallySerializable = !isSerializable && Serializable.class.isAssignableFrom(samBase);

src/java.base/share/classes/java/lang/invoke/InvokerBytecodeGenerator.java

@@ -23,6 +23,13 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2024, 2024 All Rights Reserved
+ * ===========================================================================
+ */
+
+
 package java.lang.invoke;
 
 import jdk.internal.org.objectweb.asm.ClassWriter;
@@ -111,7 +118,22 @@ private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
         if (DUMP_CLASS_FILES) {
             className = makeDumpableClassName(className);
         }
-        this.className  = className;
+        String rawUniqueID = className + invokerName + invokerType.toString() + lambdaForm.toString();
+        StringBuilder encodedUniqueID = new StringBuilder();
+        String parentheses = "(){}[]<>";
+        for (int i = 0; i < rawUniqueID.length(); i++) {
+            char currentChar = rawUniqueID.charAt(i);
+            if (Character.isLetterOrDigit(currentChar)) {
+                encodedUniqueID.append(currentChar);
+            } else {
+                if (parentheses.indexOf(currentChar) != -1) {
+                    encodedUniqueID.append("__");
+                } else {
+                    encodedUniqueID.append('_');
+                }
+            }
+        }
+        this.className = className + "$" + encodedUniqueID.toString();
         this.lambdaForm = lambdaForm;
         this.invokerName = invokerName;
         this.invokerType = invokerType;
@@ -690,6 +712,10 @@ static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType
         if (pregenerated != null)  return pregenerated; // pre-generated bytecode
 
         InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
+        Class<?> customized = MethodHandleNatives.findLambdaFormInSCC(CLASS_PREFIX + g.className, HOST_CLASS);
+        if (customized != null) {
+            return resolveInvokerMember(customized, g.invokerName, g.invokerType);
+        }
         return g.loadMethod(g.generateCustomizedCodeBytes());
     }
 
@@ -1766,6 +1792,10 @@ static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
         MethodType type = mt;  // includes leading argument
         type = type.changeParameterType(0, MethodHandle.class);
         InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
+        Class<?> customized = MethodHandleNatives.findLambdaFormInSCC(CLASS_PREFIX + g.className, HOST_CLASS);
+        if (customized != null) {
+            return resolveInvokerMember(customized, g.invokerName, g.invokerType);
+        }
         return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
     }
 
@@ -1825,6 +1855,10 @@ static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
         MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
         String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
         InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
+        Class<?> customized = MethodHandleNatives.findLambdaFormInSCC(CLASS_PREFIX + g.className, HOST_CLASS);
+        if (customized != null) {
+            return resolveInvokerMember(customized, g.invokerName, g.invokerType);
+        }
         return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
     }
 

src/java.base/share/classes/java/lang/invoke/MethodHandleNatives.java

@@ -23,6 +23,12 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2024, 2024 All Rights Reserved
+ * ===========================================================================
+ */
+
 package java.lang.invoke;
 
 import jdk.internal.ref.CleanerFactory;
@@ -49,6 +55,8 @@ private MethodHandleNatives() { } // static only
 
     static native void init(MemberName self, Object ref);
     static native void expand(MemberName self);
+    static native Class<?> findLambdaFormInSCC(String classname, Class<?> hostClass);
+    static native Class<?> findLambdaInSCC(String classname, Class<?> hostClass);
     static native MemberName resolve(MemberName self, Class<?> caller,
             boolean speculativeResolve) throws LinkageError, ClassNotFoundException;
     static native int getMembers(Class<?> defc, String matchName, String matchSig,