--- old/src/share/classes/java/lang/invoke/BoundMethodHandle.java 2015-11-30 11:39:52.000000000 +0100 +++ new/src/share/classes/java/lang/invoke/BoundMethodHandle.java 2015-11-30 11:39:52.000000000 +0100 @@ -34,14 +34,16 @@ import java.lang.invoke.MethodHandles.Lookup; import java.lang.reflect.Field; import java.util.Arrays; -import java.util.HashMap; +import java.util.function.Function; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.ConcurrentHashMap; +import jdk.internal.org.objectweb.asm.FieldVisitor; import sun.invoke.util.ValueConversions; import sun.invoke.util.Wrapper; import jdk.internal.org.objectweb.asm.ClassWriter; import jdk.internal.org.objectweb.asm.MethodVisitor; -import jdk.internal.org.objectweb.asm.Type; /** * The flavor of method handle which emulates an invoke instruction @@ -217,7 +219,7 @@ /*non-public*/ int fieldCount() { return 1; } - /*non-public*/ static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("L", Species_L.class); + /*non-public*/ static final SpeciesData SPECIES_DATA = new SpeciesData("L", Species_L.class); /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) { return new Species_L(mt, lf, argL0); } @@ -335,7 +337,7 @@ static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class); - private SpeciesData(String types, Class clazz) { + SpeciesData(String types, Class clazz) { this.typeChars = types; this.typeCodes = basicTypes(types); this.clazz = clazz; @@ -355,26 +357,14 @@ assert(!INIT_DONE); if (constructor() == null) { String types = typeChars; + CACHE.put(types, this); Factory.makeCtors(clazz, types, this.constructor); Factory.makeGetters(clazz, types, this.getters); Factory.makeNominalGetters(types, this.nominalGetters, this.getters); } } - private SpeciesData(String typeChars) { - // Placeholder only. - this.typeChars = typeChars; - this.typeCodes = basicTypes(typeChars); - this.clazz = null; - this.constructor = null; - this.getters = null; - this.nominalGetters = null; - this.extensions = null; - } - private boolean isPlaceholder() { return clazz == null; } - - private static final HashMap CACHE = new HashMap<>(); - static { CACHE.put("", EMPTY); } // make bootstrap predictable + private static final ConcurrentMap CACHE = new ConcurrentHashMap<>(); private static final boolean INIT_DONE; // set after finishes... SpeciesData extendWith(byte type) { @@ -390,62 +380,52 @@ } private static SpeciesData get(String types) { - // Acquire cache lock for query. - SpeciesData d = lookupCache(types); - if (!d.isPlaceholder()) - return d; - synchronized (d) { - // Use synch. on the placeholder to prevent multiple instantiation of one species. - // Creating this class forces a recursive call to getForClass. - if (lookupCache(types).isPlaceholder()) - Factory.generateConcreteBMHClass(types); - } - // Reacquire cache lock. - d = lookupCache(types); - // Class loading must have upgraded the cache. - assert(d != null && !d.isPlaceholder()); - return d; - } - static SpeciesData getForClass(String types, Class clazz) { - // clazz is a new class which is initializing its SPECIES_DATA field - return updateCache(types, new SpeciesData(types, clazz)); - } - private static synchronized SpeciesData lookupCache(String types) { - SpeciesData d = CACHE.get(types); - if (d != null) return d; - d = new SpeciesData(types); - assert(d.isPlaceholder()); - CACHE.put(types, d); - return d; - } - private static synchronized SpeciesData updateCache(String types, SpeciesData d) { - SpeciesData d2; - assert((d2 = CACHE.get(types)) == null || d2.isPlaceholder()); - assert(!d.isPlaceholder()); - CACHE.put(types, d); - return d; + return CACHE.computeIfAbsent(types, new Function() { + @Override + public SpeciesData apply(String types) { + Class bmhcl = Factory.getConcreteBMHClass(types); + // SpeciesData instantiation may throw VirtualMachineError because of + // code cache overflow... + SpeciesData speciesData = new SpeciesData(types, bmhcl); + // CHM.computeIfAbsent ensures only one SpeciesData will be set + // successfully on the concrete BMH class if ever + Factory.setSpeciesDataToConcreteBMHClass(bmhcl, speciesData); + // the concrete BMH class is published via SpeciesData instance + // returned here only after it's SPECIES_DATA field is set + return speciesData; + } + }); } - static { - // pre-fill the BMH speciesdata cache with BMH's inner classes - final Class rootCls = BoundMethodHandle.class; + /** + * This is to be called when assertions are enabled. It checks whether SpeciesData for all of the statically + * defined species subclasses of BoundMethodHandle has been added to the SpeciesData cache. See below in the + * static initializer for + */ + static boolean speciesDataCachePopulated() { + Class rootCls = BoundMethodHandle.class; try { for (Class c : rootCls.getDeclaredClasses()) { if (rootCls.isAssignableFrom(c)) { final Class cbmh = c.asSubclass(BoundMethodHandle.class); - SpeciesData d = Factory.speciesDataFromConcreteBMHClass(cbmh); + SpeciesData d = Factory.getSpeciesDataFromConcreteBMHClass(cbmh); assert(d != null) : cbmh.getName(); assert(d.clazz == cbmh); - assert(d == lookupCache(d.typeChars)); + assert(CACHE.get(d.typeChars) == d); } } } catch (Throwable e) { throw newInternalError(e); } + return true; + } - for (SpeciesData d : CACHE.values()) { - d.initForBootstrap(); - } + static { + // Pre-fill the BMH species-data cache with EMPTY and all BMH's inner subclasses. + EMPTY.initForBootstrap(); + Species_L.SPECIES_DATA.initForBootstrap(); + // check that all static SpeciesData instances have been initialized + assert speciesDataCachePopulated(); // Note: Do not simplify this, because INIT_DONE must not be // a compile-time constant during bootstrapping. INIT_DONE = Boolean.TRUE; @@ -479,6 +459,7 @@ static final String BMH_SIG = "L"+BMH+";"; static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData"; static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";"; + static final String STABLE_SIG = "Ljava/lang/invoke/Stable;"; static final String SPECIES_PREFIX_NAME = "Species_"; static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME; @@ -493,6 +474,26 @@ static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" }; + static final ConcurrentMap> CLASS_CACHE = new ConcurrentHashMap<>(); + + /** + * Get a concrete subclass of BMH for a given combination of bound types. + * + * @param types the type signature, wherein reference types are erased to 'L' + * @return the concrete BMH class + */ + static Class getConcreteBMHClass(String types) { + // CHM.computeIfAbsent ensures generateConcreteBMHClass is called + // only once per key. + return CLASS_CACHE.computeIfAbsent( + types, new Function>() { + @Override + public Class apply(String types) { + return generateConcreteBMHClass(types); + } + }); + } + /** * Generate a concrete subclass of BMH for a given combination of bound types. * @@ -529,7 +530,7 @@ * } * final SpeciesData speciesData() { return SPECIES_DATA; } * final int fieldCount() { return 3; } - * static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LLI", Species_LLI.class); + * @Stable static SpeciesData SPECIES_DATA; // injected afterwards * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) { * return new Species_LLI(mt, lf, argL0, argL1, argI2); * } @@ -568,7 +569,9 @@ cw.visitSource(sourceFile, null); // emit static types and SPECIES_DATA fields - cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null).visitEnd(); + FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null); + fw.visitAnnotation(STABLE_SIG, true); + fw.visitEnd(); // emit bound argument fields for (int i = 0; i < types.length(); ++i) { @@ -694,17 +697,6 @@ mv.visitEnd(); } - // emit class initializer - mv = cw.visitMethod(NOT_ACC_PUBLIC | ACC_STATIC, "", VOID_SIG, null, null); - mv.visitCode(); - mv.visitLdcInsn(types); - mv.visitLdcInsn(Type.getObjectType(className)); - mv.visitMethodInsn(INVOKESTATIC, SPECIES_DATA, "getForClass", BMHSPECIES_DATA_GFC_SIG, false); - mv.visitFieldInsn(PUTSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); - mv.visitInsn(RETURN); - mv.visitMaxs(0, 0); - mv.visitEnd(); - cw.visitEnd(); // load class @@ -715,7 +707,6 @@ UNSAFE.defineClass(className, classFile, 0, classFile.length, BoundMethodHandle.class.getClassLoader(), null) .asSubclass(BoundMethodHandle.class); - UNSAFE.ensureClassInitialized(bmhClass); return bmhClass; } @@ -785,7 +776,7 @@ // Auxiliary methods. // - static SpeciesData speciesDataFromConcreteBMHClass(Class cbmh) { + static SpeciesData getSpeciesDataFromConcreteBMHClass(Class cbmh) { try { Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); return (SpeciesData) F_SPECIES_DATA.get(null); @@ -794,6 +785,16 @@ } } + static void setSpeciesDataToConcreteBMHClass(Class cbmh, SpeciesData speciesData) { + try { + Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); + assert F_SPECIES_DATA.getDeclaredAnnotation(Stable.class) != null; + F_SPECIES_DATA.set(null, speciesData); + } catch (ReflectiveOperationException ex) { + throw newInternalError(ex); + } + } + /** * Field names in concrete BMHs adhere to this pattern: * arg + type + index