--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/klassVtable.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,353 @@
+/*
+ * Copyright (c) 1997, 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
+ * 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_KLASSVTABLE_HPP
+#define SHARE_VM_OOPS_KLASSVTABLE_HPP
+
+#include "memory/allocation.hpp"
+#include "oops/oopsHierarchy.hpp"
+#include "runtime/handles.hpp"
+#include "utilities/growableArray.hpp"
+
+// A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass
+// and ArrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable,
+// not to actually hold the vtable data.
+// Note: the klassVtable should not be accessed before the class has been verified
+// (until that point, the vtable is uninitialized).
+
+// Currently a klassVtable contains a direct reference to the vtable data, and is therefore
+// not preserved across GCs.
+
+class vtableEntry;
+
+class klassVtable VALUE_OBJ_CLASS_SPEC {
+ Klass* _klass; // my klass
+ int _tableOffset; // offset of start of vtable data within klass
+ int _length; // length of vtable (number of entries)
+#ifndef PRODUCT
+ int _verify_count; // to make verify faster
+#endif
+
+ // Ordering important, so greater_than (>) can be used as an merge operator.
+ enum AccessType {
+ acc_private = 0,
+ acc_package_private = 1,
+ acc_publicprotected = 2
+ };
+
+ public:
+ klassVtable(Klass* klass, void* base, int length) : _klass(klass) {
+ _tableOffset = (address)base - (address)klass; _length = length;
+ }
+
+ // accessors
+ vtableEntry* table() const { return (vtableEntry*)(address(_klass) + _tableOffset); }
+ Klass* klass() const { return _klass; }
+ int length() const { return _length; }
+ inline Method* method_at(int i) const;
+ inline Method* unchecked_method_at(int i) const;
+ inline Method** adr_method_at(int i) const;
+
+ // searching; all methods return -1 if not found
+ int index_of(Method* m) const { return index_of(m, _length); }
+ int index_of_miranda(Symbol* name, Symbol* signature);
+
+ void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass
+
+ // CDS/RedefineClasses support - clear vtables so they can be reinitialized
+ // at dump time. Clearing gives us an easy way to tell if the vtable has
+ // already been reinitialized at dump time (see dump.cpp). Vtables can
+ // be initialized at run time by RedefineClasses so dumping the right order
+ // is necessary.
+ void clear_vtable();
+ bool is_initialized();
+
+ // computes vtable length (in words) and the number of miranda methods
+ static void compute_vtable_size_and_num_mirandas(int* vtable_length,
+ int* num_new_mirandas,
+ GrowableArray<Method*>* all_mirandas,
+ const Klass* super,
+ Array<Method*>* methods,
+ AccessFlags class_flags,
+ u2 major_version,
+ Handle classloader,
+ Symbol* classname,
+ Array<Klass*>* local_interfaces,
+ TRAPS);
+
+#if INCLUDE_JVMTI
+ // RedefineClasses() API support:
+ // If any entry of this vtable points to any of old_methods,
+ // replace it with the corresponding new_method.
+ // trace_name_printed is set to true if the current call has
+ // printed the klass name so that other routines in the adjust_*
+ // group don't print the klass name.
+ bool adjust_default_method(int vtable_index, Method* old_method, Method* new_method);
+ void adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed);
+ bool check_no_old_or_obsolete_entries();
+ void dump_vtable();
+#endif // INCLUDE_JVMTI
+
+ // Debugging code
+ void print() PRODUCT_RETURN;
+ void verify(outputStream* st, bool force = false);
+ static void print_statistics() PRODUCT_RETURN;
+
+ protected:
+ friend class vtableEntry;
+
+ public:
+ // Transitive overridng rules for class files < JDK1_7 use the older JVMS rules.
+ // Overriding is determined as we create the vtable, so we use the class file version
+ // of the class whose vtable we are calculating.
+ enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;
+
+ private:
+ void copy_vtable_to(vtableEntry* start);
+ int initialize_from_super(Klass* super);
+ int index_of(Method* m, int len) const; // same as index_of, but search only up to len
+ void put_method_at(Method* m, int index);
+ static bool needs_new_vtable_entry(const methodHandle& m,
+ const Klass* super,
+ Handle classloader,
+ Symbol* classname,
+ AccessFlags access_flags,
+ u2 major_version,
+ TRAPS);
+
+ bool update_inherited_vtable(InstanceKlass* klass, const methodHandle& target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);
+ InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, const methodHandle& target_method, int vtable_index,
+ Handle target_loader, Symbol* target_classname, Thread* THREAD);
+
+ // support for miranda methods
+ bool is_miranda_entry_at(int i);
+ int fill_in_mirandas(int initialized);
+ static bool is_miranda(Method* m, Array<Method*>* class_methods,
+ Array<Method*>* default_methods, const Klass* super);
+ static void add_new_mirandas_to_lists(
+ GrowableArray<Method*>* new_mirandas,
+ GrowableArray<Method*>* all_mirandas,
+ Array<Method*>* current_interface_methods,
+ Array<Method*>* class_methods,
+ Array<Method*>* default_methods,
+ const Klass* super);
+ static void get_mirandas(
+ GrowableArray<Method*>* new_mirandas,
+ GrowableArray<Method*>* all_mirandas,
+ const Klass* super,
+ Array<Method*>* class_methods,
+ Array<Method*>* default_methods,
+ Array<Klass*>* local_interfaces);
+ void verify_against(outputStream* st, klassVtable* vt, int index);
+ inline InstanceKlass* ik() const;
+ // When loading a class from CDS archive at run time, and no class redefintion
+ // has happened, it is expected that the class's itable/vtables are
+ // laid out exactly the same way as they had been during dump time.
+ // Therefore, in klassVtable::initialize_[iv]table, we do not layout the
+ // tables again. Instead, we only rerun the process to create/check
+ // the class loader constraints. In non-product builds, we add asserts to
+ // guarantee that the table's layout would be the same as at dump time.
+ //
+ // If JVMTI redefines any class, the read-only shared memory are remapped
+ // as read-write. A shared class' vtable/itable are re-initialized and
+ // might have different layout due to class redefinition of the shared class
+ // or its super types.
+ bool is_preinitialized_vtable();
+};
+
+
+// private helper class for klassVtable
+// description of entry points:
+// destination is interpreted:
+// from_compiled_code_entry_point -> c2iadapter
+// from_interpreter_entry_point -> interpreter entry point
+// destination is compiled:
+// from_compiled_code_entry_point -> nmethod entry point
+// from_interpreter_entry_point -> i2cadapter
+class vtableEntry VALUE_OBJ_CLASS_SPEC {
+ friend class VMStructs;
+ friend class JVMCIVMStructs;
+
+ public:
+ // size in words
+ static int size() { return sizeof(vtableEntry) / wordSize; }
+ static int size_in_bytes() { return sizeof(vtableEntry); }
+
+ static int method_offset_in_bytes() { return offset_of(vtableEntry, _method); }
+ Method* method() const { return _method; }
+ Method** method_addr() { return &_method; }
+
+ private:
+ Method* _method;
+ void set(Method* method) { assert(method != NULL, "use clear"); _method = method; }
+ void clear() { _method = NULL; }
+ void print() PRODUCT_RETURN;
+ void verify(klassVtable* vt, outputStream* st);
+
+ friend class klassVtable;
+};
+
+
+inline Method* klassVtable::method_at(int i) const {
+ assert(i >= 0 && i < _length, "index out of bounds");
+ assert(table()[i].method() != NULL, "should not be null");
+ assert(((Metadata*)table()[i].method())->is_method(), "should be method");
+ return table()[i].method();
+}
+
+inline Method* klassVtable::unchecked_method_at(int i) const {
+ assert(i >= 0 && i < _length, "index out of bounds");
+ return table()[i].method();
+}
+
+inline Method** klassVtable::adr_method_at(int i) const {
+ // Allow one past the last entry to be referenced; useful for loop bounds.
+ assert(i >= 0 && i <= _length, "index out of bounds");
+ return (Method**)(address(table() + i) + vtableEntry::method_offset_in_bytes());
+}
+
+// --------------------------------------------------------------------------------
+class klassItable;
+class itableMethodEntry;
+
+class itableOffsetEntry VALUE_OBJ_CLASS_SPEC {
+ private:
+ Klass* _interface;
+ int _offset;
+ public:
+ Klass* interface_klass() const { return _interface; }
+ Klass**interface_klass_addr() { return &_interface; }
+ int offset() const { return _offset; }
+
+ static itableMethodEntry* method_entry(Klass* k, int offset) { return (itableMethodEntry*)(((address)k) + offset); }
+ itableMethodEntry* first_method_entry(Klass* k) { return method_entry(k, _offset); }
+
+ void initialize(Klass* interf, int offset) { _interface = interf; _offset = offset; }
+
+ // Static size and offset accessors
+ static int size() { return sizeof(itableOffsetEntry) / wordSize; } // size in words
+ static int interface_offset_in_bytes() { return offset_of(itableOffsetEntry, _interface); }
+ static int offset_offset_in_bytes() { return offset_of(itableOffsetEntry, _offset); }
+
+ friend class klassItable;
+};
+
+
+class itableMethodEntry VALUE_OBJ_CLASS_SPEC {
+ private:
+ Method* _method;
+
+ public:
+ Method* method() const { return _method; }
+ Method**method_addr() { return &_method; }
+
+ void clear() { _method = NULL; }
+
+ void initialize(Method* method);
+
+ // Static size and offset accessors
+ static int size() { return sizeof(itableMethodEntry) / wordSize; } // size in words
+ static int method_offset_in_bytes() { return offset_of(itableMethodEntry, _method); }
+
+ friend class klassItable;
+};
+
+//
+// Format of an itable
+//
+// ---- offset table ---
+// Klass* of interface 1 \
+// offset to vtable from start of oop / offset table entry
+// ...
+// Klass* of interface n \
+// offset to vtable from start of oop / offset table entry
+// --- vtable for interface 1 ---
+// Method* \
+// compiler entry point / method table entry
+// ...
+// Method* \
+// compiler entry point / method table entry
+// -- vtable for interface 2 ---
+// ...
+//
+class klassItable VALUE_OBJ_CLASS_SPEC {
+ private:
+ InstanceKlass* _klass; // my klass
+ int _table_offset; // offset of start of itable data within klass (in words)
+ int _size_offset_table; // size of offset table (in itableOffset entries)
+ int _size_method_table; // size of methodtable (in itableMethodEntry entries)
+
+ void initialize_itable_for_interface(int method_table_offset, Klass* interf_h, bool checkconstraints, TRAPS);
+ public:
+ klassItable(InstanceKlass* klass);
+
+ itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds");
+ return &((itableOffsetEntry*)vtable_start())[i]; }
+
+ itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds");
+ return &((itableMethodEntry*)method_start())[i]; }
+
+ int size_offset_table() { return _size_offset_table; }
+
+ // Initialization
+ void initialize_itable(bool checkconstraints, TRAPS);
+
+#if INCLUDE_JVMTI
+ // RedefineClasses() API support:
+ // if any entry of this itable points to any of old_methods,
+ // replace it with the corresponding new_method.
+ // trace_name_printed is set to true if the current call has
+ // printed the klass name so that other routines in the adjust_*
+ // group don't print the klass name.
+ void adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed);
+ bool check_no_old_or_obsolete_entries();
+ void dump_itable();
+#endif // INCLUDE_JVMTI
+
+ // Setup of itable
+ static int assign_itable_indices_for_interface(Klass* klass);
+ static int method_count_for_interface(Klass* klass);
+ static int compute_itable_size(Array<Klass*>* transitive_interfaces);
+ static void setup_itable_offset_table(InstanceKlass* klass);
+
+ // Resolving of method to index
+ static Method* method_for_itable_index(Klass* klass, int itable_index);
+
+ // Debugging/Statistics
+ static void print_statistics() PRODUCT_RETURN;
+ private:
+ intptr_t* vtable_start() const { return ((intptr_t*)_klass) + _table_offset; }
+ intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
+
+ // Helper methods
+ static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
+
+ // Statistics
+ NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables
+ NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables
+
+ static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
+};
+
+#endif // SHARE_VM_OOPS_KLASSVTABLE_HPP