# HG changeset patch # User Thomas Wuerthinger # Date 1485310916 -3600 # Node ID 33421fb951da28839e05c3ae0e8f2118f1c5f84b # Parent 6d2c72b822b01cfe52a9c47f5d402755a3635e8f Fix footprint issue in HotSpotResolvedObjectTypeImpl by reducing use of java.util.HashMap. diff -r 6d2c72b822b0 -r 33421fb951da jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedObjectTypeImpl.java --- a/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedObjectTypeImpl.java Tue Jan 24 13:03:27 2017 +0100 +++ b/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedObjectTypeImpl.java Wed Jan 25 03:21:56 2017 +0100 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2011, 2016, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -35,8 +35,6 @@ import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.nio.ByteOrder; -import java.util.ArrayList; -import java.util.Arrays; import java.util.HashMap; import jdk.vm.ci.common.JVMCIError; @@ -58,12 +56,15 @@ */ final class HotSpotResolvedObjectTypeImpl extends HotSpotResolvedJavaType implements HotSpotResolvedObjectType, MetaspaceWrapperObject { + private static final HotSpotResolvedJavaField[] NO_FIELDS = new HotSpotResolvedJavaField[0]; + private static final int METHOD_CACHE_ARRAY_CAPACITY = 8; + /** * The Java class this type represents. */ private final Class javaClass; - private HashMap fieldCache; - private HashMap methodCache; + private HotSpotResolvedJavaMethodImpl[] methodCacheArray; + private HashMap methodCacheHashMap; private HotSpotResolvedJavaField[] instanceFields; private HotSpotResolvedObjectTypeImpl[] interfaces; private HotSpotConstantPool constantPool; @@ -478,18 +479,38 @@ } synchronized HotSpotResolvedJavaMethod createMethod(long metaspaceMethod) { - HotSpotResolvedJavaMethodImpl method = null; - if (methodCache == null) { - methodCache = new HashMap<>(8); - } else { - method = methodCache.get(metaspaceMethod); + // Maintain cache as array. + if (methodCacheArray == null) { + methodCacheArray = new HotSpotResolvedJavaMethodImpl[METHOD_CACHE_ARRAY_CAPACITY]; } - if (method == null) { - method = new HotSpotResolvedJavaMethodImpl(this, metaspaceMethod); - methodCache.put(metaspaceMethod, method); - context.add(method); + + int i = 0; + for (; i < methodCacheArray.length; ++i) { + HotSpotResolvedJavaMethodImpl curMethod = methodCacheArray[i]; + if (curMethod == null) { + HotSpotResolvedJavaMethodImpl newMethod = new HotSpotResolvedJavaMethodImpl(this, metaspaceMethod); + methodCacheArray[i] = newMethod; + context.add(newMethod); + return newMethod; + } else if (curMethod.getMetaspacePointer() == metaspaceMethod) { + return curMethod; + } } - return method; + + // Fall-back to hash table. + if (methodCacheHashMap == null) { + methodCacheHashMap = new HashMap<>(); + } + + HotSpotResolvedJavaMethodImpl lookupResult = methodCacheHashMap.get(metaspaceMethod); + if (lookupResult == null) { + HotSpotResolvedJavaMethodImpl newMethod = new HotSpotResolvedJavaMethodImpl(this, metaspaceMethod); + methodCacheHashMap.put(metaspaceMethod, newMethod); + context.add(lookupResult); + return newMethod; + } else { + return lookupResult; + } } public int getVtableLength() { @@ -504,36 +525,7 @@ } synchronized HotSpotResolvedJavaField createField(String fieldName, JavaType type, long offset, int rawFlags) { - HotSpotResolvedJavaField result = null; - - final int flags = rawFlags & HotSpotModifiers.jvmFieldModifiers(); - - final long id = offset + ((long) flags << 32); - - // Must cache the fields, because the local load elimination only works if the - // objects from two field lookups are identical. - if (fieldCache == null) { - fieldCache = new HashMap<>(8); - } else { - result = fieldCache.get(id); - } - - if (result == null) { - result = new HotSpotResolvedJavaFieldImpl(this, fieldName, type, offset, rawFlags); - fieldCache.put(id, result); - } else { - assert result.getName().equals(fieldName); - /* - * Comparing the types directly is too strict, because the type in the cache could be - * resolved while the incoming type is unresolved. The name comparison is sufficient - * because the type will always be resolved in the context of the holder. - */ - assert result.getType().getName().equals(type.getName()); - assert result.offset() == offset; - assert result.getModifiers() == flags; - } - - return result; + return new HotSpotResolvedJavaFieldImpl(this, fieldName, type, offset, rawFlags); } @Override @@ -660,61 +652,31 @@ } } - @SuppressFBWarnings(value = "SE_COMPARATOR_SHOULD_BE_SERIALIZABLE", justification = "comparator is only used transiently") - private static class OffsetComparator implements java.util.Comparator { - @Override - public int compare(HotSpotResolvedJavaField o1, HotSpotResolvedJavaField o2) { - return o1.offset() - o2.offset(); - } - } - @Override public ResolvedJavaField[] getInstanceFields(boolean includeSuperclasses) { if (instanceFields == null) { if (isArray() || isInterface()) { - instanceFields = new HotSpotResolvedJavaField[0]; + instanceFields = NO_FIELDS; } else { - final int fieldCount = getFieldCount(); - ArrayList fieldsArray = new ArrayList<>(fieldCount); - - for (int i = 0; i < fieldCount; i++) { - FieldInfo field = new FieldInfo(i); - - // We are only interested in instance fields. - if (!field.isStatic()) { - HotSpotResolvedJavaField resolvedJavaField = createField(field.getName(), field.getType(), field.getOffset(), field.getAccessFlags()); - fieldsArray.add(resolvedJavaField); - } + HotSpotResolvedJavaField[] prepend = NO_FIELDS; + if (getSuperclass() != null) { + prepend = (HotSpotResolvedJavaField[]) getSuperclass().getInstanceFields(true); } - - fieldsArray.sort(new OffsetComparator()); - - HotSpotResolvedJavaField[] myFields = fieldsArray.toArray(new HotSpotResolvedJavaField[0]); - - if (mirror() != Object.class) { - HotSpotResolvedJavaField[] superFields = (HotSpotResolvedJavaField[]) getSuperclass().getInstanceFields(true); - HotSpotResolvedJavaField[] fields = Arrays.copyOf(superFields, superFields.length + myFields.length); - System.arraycopy(myFields, 0, fields, superFields.length, myFields.length); - instanceFields = fields; - } else { - assert myFields.length == 0 : "java.lang.Object has fields!"; - instanceFields = myFields; - } - + instanceFields = getFields(false, prepend); } } - if (!includeSuperclasses) { - int myFieldsStart = 0; - while (myFieldsStart < instanceFields.length && !instanceFields[myFieldsStart].getDeclaringClass().equals(this)) { - myFieldsStart++; + if (!includeSuperclasses && getSuperclass() != null) { + int superClassFieldCount = getSuperclass().getInstanceFields(true).length; + if (superClassFieldCount == instanceFields.length) { + // This class does not have any instance fields of its own. + return NO_FIELDS; + } else if (superClassFieldCount != 0) { + HotSpotResolvedJavaField[] result = new HotSpotResolvedJavaField[instanceFields.length - superClassFieldCount]; + System.arraycopy(instanceFields, superClassFieldCount, result, 0, result.length); + return result; + } else { + // The super classes of this class do not have any instance fields. } - if (myFieldsStart == 0) { - return instanceFields; - } - if (myFieldsStart == instanceFields.length) { - return new HotSpotResolvedJavaField[0]; - } - return Arrays.copyOfRange(instanceFields, myFieldsStart, instanceFields.length); } return instanceFields; } @@ -724,21 +686,7 @@ if (isArray()) { return new HotSpotResolvedJavaField[0]; } else { - final int fieldCount = getFieldCount(); - ArrayList fieldsArray = new ArrayList<>(fieldCount); - - for (int i = 0; i < fieldCount; i++) { - FieldInfo field = new FieldInfo(i); - - // We are only interested in static fields. - if (field.isStatic()) { - HotSpotResolvedJavaField resolvedJavaField = createField(field.getName(), field.getType(), field.getOffset(), field.getAccessFlags()); - fieldsArray.add(resolvedJavaField); - } - } - - fieldsArray.sort(new OffsetComparator()); - return fieldsArray.toArray(new HotSpotResolvedJavaField[fieldsArray.size()]); + return getFields(true, NO_FIELDS); } } @@ -749,20 +697,53 @@ *

* See {@code FieldStreamBase::init_generic_signature_start_slot} */ - private int getFieldCount() { + private HotSpotResolvedJavaField[] getFields(boolean retrieveStaticFields, HotSpotResolvedJavaField[] prepend) { HotSpotVMConfig config = config(); final long metaspaceFields = UNSAFE.getAddress(getMetaspaceKlass() + config.instanceKlassFieldsOffset); int metaspaceFieldsLength = UNSAFE.getInt(metaspaceFields + config.arrayU1LengthOffset); - int fieldCount = 0; - - for (int i = 0, index = 0; i < metaspaceFieldsLength; i += config.fieldInfoFieldSlots, index++) { + int resultCount = 0; + int index = 0; + for (int i = 0; i < metaspaceFieldsLength; i += config.fieldInfoFieldSlots, index++) { FieldInfo field = new FieldInfo(index); if (field.hasGenericSignature()) { metaspaceFieldsLength--; } - fieldCount++; + + if (field.isStatic() == retrieveStaticFields) { + resultCount++; + } + } + + if (resultCount == 0) { + return prepend; + } + + int prependLength = prepend.length; + resultCount += prependLength; + + HotSpotResolvedJavaField[] result = new HotSpotResolvedJavaField[resultCount]; + if (prependLength != 0) { + System.arraycopy(prepend, 0, result, 0, prependLength); } - return fieldCount; + + int resultIndex = prependLength; + for (int i = 0; i < index; ++i) { + FieldInfo field = new FieldInfo(i); + if (field.isStatic() == retrieveStaticFields) { + int offset = field.getOffset(); + HotSpotResolvedJavaField resolvedJavaField = createField(field.getName(), field.getType(), offset, field.getAccessFlags()); + + // Make sure the result is sorted by offset. + int j; + for (j = resultIndex - 1; j >= prependLength && result[j].offset() > offset; j--) { + result[j + 1] = result[j]; + } + result[j + 1] = resolvedJavaField; + resultIndex++; + } + } + + return result; } @Override