--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/fieldInfo.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2011, 2015, 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.
+ *
+ */
+
+#ifndef SHARE_VM_OOPS_FIELDINFO_HPP
+#define SHARE_VM_OOPS_FIELDINFO_HPP
+
+#include "oops/constantPool.hpp"
+#include "oops/typeArrayOop.hpp"
+#include "classfile/vmSymbols.hpp"
+
+// This class represents the field information contained in the fields
+// array of an InstanceKlass. Currently it's laid on top an array of
+// Java shorts but in the future it could simply be used as a real
+// array type. FieldInfo generally shouldn't be used directly.
+// Fields should be queried either through InstanceKlass or through
+// the various FieldStreams.
+class FieldInfo VALUE_OBJ_CLASS_SPEC {
+ friend class fieldDescriptor;
+ friend class JavaFieldStream;
+ friend class ClassFileParser;
+
+ public:
+ // fields
+ // Field info extracted from the class file and stored
+ // as an array of 6 shorts.
+
+#define FIELDINFO_TAG_SIZE 2
+#define FIELDINFO_TAG_BLANK 0
+#define FIELDINFO_TAG_OFFSET 1
+#define FIELDINFO_TAG_TYPE_PLAIN 2
+#define FIELDINFO_TAG_TYPE_CONTENDED 3
+#define FIELDINFO_TAG_MASK 3
+
+ // Packed field has the tag, and can be either of:
+ // hi bits <--------------------------- lo bits
+ // |---------high---------|---------low---------|
+ // ..........................................00 - blank
+ // [------------------offset----------------]01 - real field offset
+ // ......................[-------type-------]10 - plain field with type
+ // [--contention_group--][-------type-------]11 - contended field with type and contention group
+ enum FieldOffset {
+ access_flags_offset = 0,
+ name_index_offset = 1,
+ signature_index_offset = 2,
+ initval_index_offset = 3,
+ low_packed_offset = 4,
+ high_packed_offset = 5,
+ field_slots = 6
+ };
+
+ private:
+ u2 _shorts[field_slots];
+
+ void set_name_index(u2 val) { _shorts[name_index_offset] = val; }
+ void set_signature_index(u2 val) { _shorts[signature_index_offset] = val; }
+ void set_initval_index(u2 val) { _shorts[initval_index_offset] = val; }
+
+ u2 name_index() const { return _shorts[name_index_offset]; }
+ u2 signature_index() const { return _shorts[signature_index_offset]; }
+ u2 initval_index() const { return _shorts[initval_index_offset]; }
+
+ public:
+ static FieldInfo* from_field_array(Array<u2>* fields, int index) {
+ return ((FieldInfo*)fields->adr_at(index * field_slots));
+ }
+ static FieldInfo* from_field_array(u2* fields, int index) {
+ return ((FieldInfo*)(fields + index * field_slots));
+ }
+
+ void initialize(u2 access_flags,
+ u2 name_index,
+ u2 signature_index,
+ u2 initval_index) {
+ _shorts[access_flags_offset] = access_flags;
+ _shorts[name_index_offset] = name_index;
+ _shorts[signature_index_offset] = signature_index;
+ _shorts[initval_index_offset] = initval_index;
+ _shorts[low_packed_offset] = 0;
+ _shorts[high_packed_offset] = 0;
+ }
+
+ u2 access_flags() const { return _shorts[access_flags_offset]; }
+ u4 offset() const {
+ u2 lo = _shorts[low_packed_offset];
+ switch(lo & FIELDINFO_TAG_MASK) {
+ case FIELDINFO_TAG_OFFSET:
+ return build_int_from_shorts(_shorts[low_packed_offset], _shorts[high_packed_offset]) >> FIELDINFO_TAG_SIZE;
+#ifndef PRODUCT
+ case FIELDINFO_TAG_TYPE_PLAIN:
+ fatal("Asking offset for the plain type field");
+ case FIELDINFO_TAG_TYPE_CONTENDED:
+ fatal("Asking offset for the contended type field");
+ case FIELDINFO_TAG_BLANK:
+ fatal("Asking offset for the blank field");
+#endif
+ }
+ ShouldNotReachHere();
+ return 0;
+ }
+
+ bool is_contended() const {
+ u2 lo = _shorts[low_packed_offset];
+ switch(lo & FIELDINFO_TAG_MASK) {
+ case FIELDINFO_TAG_TYPE_PLAIN:
+ return false;
+ case FIELDINFO_TAG_TYPE_CONTENDED:
+ return true;
+#ifndef PRODUCT
+ case FIELDINFO_TAG_OFFSET:
+ fatal("Asking contended flag for the field with offset");
+ case FIELDINFO_TAG_BLANK:
+ fatal("Asking contended flag for the blank field");
+#endif
+ }
+ ShouldNotReachHere();
+ return false;
+ }
+
+ u2 contended_group() const {
+ u2 lo = _shorts[low_packed_offset];
+ switch(lo & FIELDINFO_TAG_MASK) {
+ case FIELDINFO_TAG_TYPE_PLAIN:
+ return 0;
+ case FIELDINFO_TAG_TYPE_CONTENDED:
+ return _shorts[high_packed_offset];
+#ifndef PRODUCT
+ case FIELDINFO_TAG_OFFSET:
+ fatal("Asking the contended group for the field with offset");
+ case FIELDINFO_TAG_BLANK:
+ fatal("Asking the contended group for the blank field");
+#endif
+ }
+ ShouldNotReachHere();
+ return 0;
+ }
+
+ u2 allocation_type() const {
+ u2 lo = _shorts[low_packed_offset];
+ switch(lo & FIELDINFO_TAG_MASK) {
+ case FIELDINFO_TAG_TYPE_PLAIN:
+ case FIELDINFO_TAG_TYPE_CONTENDED:
+ return (lo >> FIELDINFO_TAG_SIZE);
+#ifndef PRODUCT
+ case FIELDINFO_TAG_OFFSET:
+ fatal("Asking the field type for field with offset");
+ case FIELDINFO_TAG_BLANK:
+ fatal("Asking the field type for the blank field");
+#endif
+ }
+ ShouldNotReachHere();
+ return 0;
+ }
+
+ bool is_offset_set() const {
+ return (_shorts[low_packed_offset] & FIELDINFO_TAG_MASK) == FIELDINFO_TAG_OFFSET;
+ }
+
+ Symbol* name(const constantPoolHandle& cp) const {
+ int index = name_index();
+ if (is_internal()) {
+ return lookup_symbol(index);
+ }
+ return cp->symbol_at(index);
+ }
+
+ Symbol* signature(const constantPoolHandle& cp) const {
+ int index = signature_index();
+ if (is_internal()) {
+ return lookup_symbol(index);
+ }
+ return cp->symbol_at(index);
+ }
+
+ void set_access_flags(u2 val) { _shorts[access_flags_offset] = val; }
+ void set_offset(u4 val) {
+ val = val << FIELDINFO_TAG_SIZE; // make room for tag
+ _shorts[low_packed_offset] = extract_low_short_from_int(val) | FIELDINFO_TAG_OFFSET;
+ _shorts[high_packed_offset] = extract_high_short_from_int(val);
+ }
+
+ void set_allocation_type(int type) {
+ u2 lo = _shorts[low_packed_offset];
+ switch(lo & FIELDINFO_TAG_MASK) {
+ case FIELDINFO_TAG_BLANK:
+ _shorts[low_packed_offset] = ((type << FIELDINFO_TAG_SIZE)) & 0xFFFF;
+ _shorts[low_packed_offset] &= ~FIELDINFO_TAG_MASK;
+ _shorts[low_packed_offset] |= FIELDINFO_TAG_TYPE_PLAIN;
+ return;
+#ifndef PRODUCT
+ case FIELDINFO_TAG_TYPE_PLAIN:
+ case FIELDINFO_TAG_TYPE_CONTENDED:
+ case FIELDINFO_TAG_OFFSET:
+ fatal("Setting the field type with overwriting");
+#endif
+ }
+ ShouldNotReachHere();
+ }
+
+ void set_contended_group(u2 val) {
+ u2 lo = _shorts[low_packed_offset];
+ switch(lo & FIELDINFO_TAG_MASK) {
+ case FIELDINFO_TAG_TYPE_PLAIN:
+ _shorts[low_packed_offset] |= FIELDINFO_TAG_TYPE_CONTENDED;
+ _shorts[high_packed_offset] = val;
+ return;
+#ifndef PRODUCT
+ case FIELDINFO_TAG_TYPE_CONTENDED:
+ fatal("Overwriting contended group");
+ case FIELDINFO_TAG_BLANK:
+ fatal("Setting contended group for the blank field");
+ case FIELDINFO_TAG_OFFSET:
+ fatal("Setting contended group for field with offset");
+#endif
+ }
+ ShouldNotReachHere();
+ }
+
+ bool is_internal() const {
+ return (access_flags() & JVM_ACC_FIELD_INTERNAL) != 0;
+ }
+
+ bool is_stable() const {
+ return (access_flags() & JVM_ACC_FIELD_STABLE) != 0;
+ }
+ void set_stable(bool z) {
+ if (z) _shorts[access_flags_offset] |= JVM_ACC_FIELD_STABLE;
+ else _shorts[access_flags_offset] &= ~JVM_ACC_FIELD_STABLE;
+ }
+
+ Symbol* lookup_symbol(int symbol_index) const {
+ assert(is_internal(), "only internal fields");
+ return vmSymbols::symbol_at((vmSymbols::SID)symbol_index);
+ }
+};
+
+#endif // SHARE_VM_OOPS_FIELDINFO_HPP