| /* |
| * 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 |
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| * |
| */ |
| |
| #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 |