| /* | |
| * Copyright (c) 2010, 2019, 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 | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
| * 2 along with this work; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| package jdk.vm.ci.code; | |
| import java.util.Collections; | |
| import java.util.IdentityHashMap; | |
| import java.util.Set; | |
| import jdk.vm.ci.common.JVMCIError; | |
| import jdk.vm.ci.meta.JavaKind; | |
| import jdk.vm.ci.meta.JavaValue; | |
| import jdk.vm.ci.meta.ResolvedJavaField; | |
| import jdk.vm.ci.meta.ResolvedJavaType; | |
| /** | |
| * An instance of this class represents an object whose allocation was removed by escape analysis. | |
| * The information stored in the {@link VirtualObject} is used during deoptimization to recreate the | |
| * object. | |
| */ | |
| public final class VirtualObject implements JavaValue { | |
| private final ResolvedJavaType type; | |
| private JavaValue[] values; | |
| private JavaKind[] slotKinds; | |
| private final int id; | |
| private boolean isAutoBox; | |
| /** | |
| * Creates a new {@link VirtualObject} for the given type, with the given fields. If | |
| * {@code type} is an instance class then {@code values} provides the values for the fields | |
| * returned by {@link ResolvedJavaType#getInstanceFields(boolean) getInstanceFields(true)}. If | |
| * {@code type} is an array then the length of the values array determines the reallocated array | |
| * length. | |
| * | |
| * @param type the type of the object whose allocation was removed during compilation. This can | |
| * be either an instance of an array type. | |
| * @param id a unique id that identifies the object within the debug information for one | |
| * position in the compiled code. | |
| * @return a new {@link VirtualObject} instance. | |
| */ | |
| public static VirtualObject get(ResolvedJavaType type, int id) { | |
| return new VirtualObject(type, id, false); | |
| } | |
| /** | |
| * Creates a new {@link VirtualObject} for the given type, with the given fields. If | |
| * {@code type} is an instance class then {@code values} provides the values for the fields | |
| * returned by {@link ResolvedJavaType#getInstanceFields(boolean) getInstanceFields(true)}. If | |
| * {@code type} is an array then the length of the values array determines the reallocated array | |
| * length. | |
| * | |
| * @param type the type of the object whose allocation was removed during compilation. This can | |
| * be either an instance of an array type. | |
| * @param id a unique id that identifies the object within the debug information for one | |
| * position in the compiled code. | |
| * @param isAutoBox a flag that tells the runtime that the object may be a boxed primitive and | |
| * that it possibly needs to be obtained from the box cache instead of creating a new | |
| * instance. | |
| * @return a new {@link VirtualObject} instance. | |
| */ | |
| public static VirtualObject get(ResolvedJavaType type, int id, boolean isAutoBox) { | |
| return new VirtualObject(type, id, isAutoBox); | |
| } | |
| private VirtualObject(ResolvedJavaType type, int id, boolean isAutoBox) { | |
| this.type = type; | |
| this.id = id; | |
| this.isAutoBox = isAutoBox; | |
| } | |
| private static StringBuilder appendValue(StringBuilder buf, JavaValue value, Set<VirtualObject> visited) { | |
| if (value instanceof VirtualObject) { | |
| VirtualObject vo = (VirtualObject) value; | |
| buf.append("vobject:").append(vo.type.toJavaName(false)).append(':').append(vo.id); | |
| if (!visited.contains(vo)) { | |
| visited.add(vo); | |
| buf.append('{'); | |
| if (vo.values == null) { | |
| buf.append("<uninitialized>"); | |
| } else { | |
| if (vo.type.isArray()) { | |
| for (int i = 0; i < vo.values.length; i++) { | |
| if (i != 0) { | |
| buf.append(','); | |
| } | |
| buf.append(i).append('='); | |
| appendValue(buf, vo.values[i], visited); | |
| } | |
| } else { | |
| ResolvedJavaField[] fields = vo.type.getInstanceFields(true); | |
| int fieldIndex = 0; | |
| for (int i = 0; i < vo.values.length; i++, fieldIndex++) { | |
| if (i != 0) { | |
| buf.append(','); | |
| } | |
| if (fieldIndex >= fields.length) { | |
| buf.append("<missing field>"); | |
| } else { | |
| ResolvedJavaField field = fields[fieldIndex]; | |
| buf.append(field.getName()); | |
| if (vo.slotKinds[i].getSlotCount() == 2 && field.getType().getJavaKind().getSlotCount() == 1) { | |
| if (fieldIndex + 1 >= fields.length) { | |
| buf.append("/<missing field>"); | |
| } else { | |
| ResolvedJavaField field2 = fields[++fieldIndex]; | |
| buf.append('/').append(field2.getName()); | |
| } | |
| } | |
| } | |
| buf.append('='); | |
| appendValue(buf, vo.values[i], visited); | |
| } | |
| // Extra fields | |
| for (; fieldIndex < fields.length; fieldIndex++) { | |
| buf.append(fields[fieldIndex].getName()).append("=<missing value>"); | |
| } | |
| } | |
| } | |
| buf.append('}'); | |
| } | |
| } else { | |
| buf.append(value); | |
| } | |
| return buf; | |
| } | |
| public interface LayoutVerifier { | |
| int getOffset(ResolvedJavaField field); | |
| default JavaKind getStorageKind(ResolvedJavaField field) { | |
| return field.getType().getJavaKind(); | |
| } | |
| } | |
| public void verifyLayout(LayoutVerifier verifier) { | |
| if (!type.isArray()) { | |
| ResolvedJavaField[] fields = type.getInstanceFields(true); | |
| int fieldIndex = 0; | |
| for (int i = 0; i < values.length; i++, fieldIndex++) { | |
| JavaKind slotKind = slotKinds[i]; | |
| if (fieldIndex >= fields.length) { | |
| throw new JVMCIError("Not enough fields for the values provided for %s", toString()); | |
| } else { | |
| ResolvedJavaField field = fields[fieldIndex]; | |
| JavaKind fieldKind = verifier.getStorageKind(field); | |
| if (slotKind.getSlotCount() == 2 && fieldKind == JavaKind.Int) { | |
| int offset = verifier.getOffset(field); | |
| if (offset % 8 != 0) { | |
| throw new JVMCIError("Double word value stored across two ints must be aligned %s", toString()); | |
| } | |
| if (fieldIndex + 1 >= fields.length) { | |
| throw new JVMCIError("Missing second field for double word value stored in two ints %s", toString()); | |
| } | |
| ResolvedJavaField field2 = fields[fieldIndex + 1]; | |
| if (field2.getType().getJavaKind() != JavaKind.Int) { | |
| throw new JVMCIError("Second field for double word value stored in two ints must be int but got %s in %s", field2.getType().getJavaKind(), toString()); | |
| } | |
| int offset2 = verifier.getOffset(field2); | |
| if (offset + 4 != offset2) { | |
| throw new JVMCIError("Double word value stored across two ints must be sequential %s", toString()); | |
| } | |
| fieldIndex++; | |
| } else if (fieldKind.getStackKind() != slotKind.getStackKind()) { | |
| throw new JVMCIError("Expected value of kind %s but got %s for field %s in %s", fieldKind, slotKind, field, toString()); | |
| } | |
| } | |
| } | |
| // Extra fields | |
| if (fieldIndex < fields.length) { | |
| throw new JVMCIError("Not enough values provided for fields in %s", this); | |
| } | |
| } else if (type.getComponentType().getJavaKind() == JavaKind.Byte) { | |
| for (int i = 0; i < values.length;) { | |
| JavaKind slotkind = slotKinds[i]; | |
| if (slotkind != JavaKind.Byte) { | |
| if (!slotkind.isPrimitive()) { | |
| throw new JVMCIError("Storing a non-primitive in a byte array: %s %s", slotkind, toString()); | |
| } | |
| int byteCount = 1; | |
| while (++i < values.length && slotKinds[i] == JavaKind.Illegal) { | |
| byteCount++; | |
| } | |
| /* | |
| * Checks: a) The byte count is a valid count (ie: power of two), b) if the kind | |
| * was not erased to int (happens for regular byte array accesses), check that | |
| * the count is correct, c) No writes spanning more than a long. | |
| */ | |
| if (!CodeUtil.isPowerOf2(byteCount) || (slotkind.getStackKind() != JavaKind.Int && byteCount != slotkind.getByteCount()) || byteCount > JavaKind.Long.getByteCount()) { | |
| throw new JVMCIError("Invalid number of illegals to reconstruct a byte array: %s in %s", byteCount, toString()); | |
| } | |
| continue; | |
| } | |
| i++; | |
| } | |
| } | |
| } | |
| @Override | |
| public String toString() { | |
| Set<VirtualObject> visited = Collections.newSetFromMap(new IdentityHashMap<VirtualObject, Boolean>()); | |
| return appendValue(new StringBuilder(), this, visited).toString(); | |
| } | |
| /** | |
| * Returns the type of the object whose allocation was removed during compilation. This can be | |
| * either an instance of an array type. | |
| */ | |
| public ResolvedJavaType getType() { | |
| return type; | |
| } | |
| /** | |
| * Returns the array containing all the values to be stored into the object when it is | |
| * recreated. This field is intentional exposed as a mutable array that a compiler may modify | |
| * (e.g. during register allocation). | |
| */ | |
| @SuppressFBWarnings(value = "EI_EXPOSE_REP", justification = "`values` is intentional mutable")// | |
| public JavaValue[] getValues() { | |
| return values; | |
| } | |
| /** | |
| * Returns the kind of the value at {@code index}. | |
| */ | |
| public JavaKind getSlotKind(int index) { | |
| return slotKinds[index]; | |
| } | |
| /** | |
| * Returns the unique id that identifies the object within the debug information for one | |
| * position in the compiled code. | |
| */ | |
| public int getId() { | |
| return id; | |
| } | |
| /** | |
| * Returns true if the object is a box. For boxes the deoptimization would check if the value of | |
| * the box is in the cache range and try to return a cached object. | |
| */ | |
| public boolean isAutoBox() { | |
| return isAutoBox; | |
| } | |
| /** | |
| * Overwrites the current set of values with a new one. | |
| * | |
| * @param values an array containing all the values to be stored into the object when it is | |
| * recreated. | |
| * @param slotKinds an array containing the Java kinds of the values. This must have the same | |
| * length as {@code values}. This array is now owned by this object and must not be | |
| * mutated by the caller. | |
| */ | |
| @SuppressFBWarnings(value = "EI_EXPOSE_REP2", justification = "caller transfers ownership of `slotKinds`") | |
| public void setValues(JavaValue[] values, JavaKind[] slotKinds) { | |
| assert values.length == slotKinds.length; | |
| this.values = values; | |
| this.slotKinds = slotKinds; | |
| } | |
| @Override | |
| public int hashCode() { | |
| return 42 + type.hashCode(); | |
| } | |
| @Override | |
| public boolean equals(Object o) { | |
| if (o == this) { | |
| return true; | |
| } | |
| if (o instanceof VirtualObject) { | |
| VirtualObject l = (VirtualObject) o; | |
| if (!l.type.equals(type) || l.values.length != values.length) { | |
| return false; | |
| } | |
| for (int i = 0; i < values.length; i++) { | |
| /* | |
| * Virtual objects can form cycles. Calling equals() could therefore lead to | |
| * infinite recursion. | |
| */ | |
| if (!same(values[i], l.values[i])) { | |
| return false; | |
| } | |
| } | |
| return true; | |
| } | |
| return false; | |
| } | |
| private static boolean same(Object o1, Object o2) { | |
| return o1 == o2; | |
| } | |
| } |