| /* |
| * Copyright 1998-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| * |
| */ |
| |
| // A ConstantPoolCacheEntry describes an individual entry of the constant |
| // pool cache. There's 2 principal kinds of entries: field entries for in- |
| // stance & static field access, and method entries for invokes. Some of |
| // the entry layout is shared and looks as follows: |
| // |
| // bit number |31 0| |
| // bit length |-8--|-8--|---16----| |
| // -------------------------------- |
| // _indices [ b2 | b1 | index ] |
| // _f1 [ entry specific ] |
| // _f2 [ entry specific ] |
| // _flags [t|f|vf|v|m|h|unused|field_index] (for field entries) |
| // bit length |4|1|1 |1|1|0|---7--|----16-----] |
| // _flags [t|f|vf|v|m|h|unused|eidx|psze] (for method entries) |
| // bit length |4|1|1 |1|1|1|---7--|-8--|-8--] |
| |
| // -------------------------------- |
| // |
| // with: |
| // index = original constant pool index |
| // b1 = bytecode 1 |
| // b2 = bytecode 2 |
| // psze = parameters size (method entries only) |
| // eidx = interpreter entry index (method entries only) |
| // field_index = index into field information in holder instanceKlass |
| // The index max is 0xffff (max number of fields in constant pool) |
| // and is multiplied by (instanceKlass::next_offset) when accessing. |
| // t = TosState (see below) |
| // f = field is marked final (see below) |
| // vf = virtual, final (method entries only : is_vfinal()) |
| // v = field is volatile (see below) |
| // m = invokeinterface used for method in class Object (see below) |
| // h = RedefineClasses/Hotswap bit (see below) |
| // |
| // The flags after TosState have the following interpretation: |
| // bit 27: f flag true if field is marked final |
| // bit 26: vf flag true if virtual final method |
| // bit 25: v flag true if field is volatile (only for fields) |
| // bit 24: m flag true if invokeinterface used for method in class Object |
| // bit 23: 0 for fields, 1 for methods |
| // |
| // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the |
| // following mapping to the TosState states: |
| // |
| // btos: 0 |
| // ctos: 1 |
| // stos: 2 |
| // itos: 3 |
| // ltos: 4 |
| // ftos: 5 |
| // dtos: 6 |
| // atos: 7 |
| // vtos: 8 |
| // |
| // Entry specific: field entries: |
| // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index |
| // _f1 = field holder |
| // _f2 = field offset in words |
| // _flags = field type information, original field index in field holder |
| // (field_index section) |
| // |
| // Entry specific: method entries: |
| // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section), |
| // original constant pool index |
| // _f1 = method for all but virtual calls, unused by virtual calls |
| // (note: for interface calls, which are essentially virtual, |
| // contains klassOop for the corresponding interface. |
| // _f2 = method/vtable index for virtual calls only, unused by all other |
| // calls. The vf flag indicates this is a method pointer not an |
| // index. |
| // _flags = field type info (f section), |
| // virtual final entry (vf), |
| // interpreter entry index (eidx section), |
| // parameter size (psze section) |
| // |
| // Note: invokevirtual & invokespecial bytecodes can share the same constant |
| // pool entry and thus the same constant pool cache entry. All invoke |
| // bytecodes but invokevirtual use only _f1 and the corresponding b1 |
| // bytecode, while invokevirtual uses only _f2 and the corresponding |
| // b2 bytecode. The value of _flags is shared for both types of entries. |
| // |
| // The fields are volatile so that they are stored in the order written in the |
| // source code. The _indices field with the bytecode must be written last. |
| |
| class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC { |
| friend class VMStructs; |
| private: |
| volatile intx _indices; // constant pool index & rewrite bytecodes |
| volatile oop _f1; // entry specific oop field |
| volatile intx _f2; // entry specific int/oop field |
| volatile intx _flags; // flags |
| |
| |
| #ifdef ASSERT |
| bool same_methodOop(oop cur_f1, oop f1); |
| #endif |
| |
| void set_bytecode_1(Bytecodes::Code code); |
| void set_bytecode_2(Bytecodes::Code code); |
| void set_f1(oop f1) { |
| oop existing_f1 = _f1; // read once |
| assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change"); |
| oop_store(&_f1, f1); |
| } |
| void set_f2(intx f2) { assert(_f2 == 0 || _f2 == f2, "illegal field change"); _f2 = f2; } |
| int as_flags(TosState state, bool is_final, bool is_vfinal, bool is_volatile, |
| bool is_method_interface, bool is_method); |
| void set_flags(intx flags) { _flags = flags; } |
| |
| public: |
| // specific bit values in flag field |
| // Note: the interpreter knows this layout! |
| enum FlagBitValues { |
| hotSwapBit = 23, |
| methodInterface = 24, |
| volatileField = 25, |
| vfinalMethod = 26, |
| finalField = 27 |
| }; |
| |
| enum { field_index_mask = 0xFFFF }; |
| |
| // start of type bits in flags |
| // Note: the interpreter knows this layout! |
| enum FlagValues { |
| tosBits = 28 |
| }; |
| |
| // Initialization |
| void set_initial_state(int index); // sets entry to initial state |
| |
| void set_field( // sets entry to resolved field state |
| Bytecodes::Code get_code, // the bytecode used for reading the field |
| Bytecodes::Code put_code, // the bytecode used for writing the field |
| KlassHandle field_holder, // the object/klass holding the field |
| int orig_field_index, // the original field index in the field holder |
| int field_offset, // the field offset in words in the field holder |
| TosState field_type, // the (machine) field type |
| bool is_final, // the field is final |
| bool is_volatile // the field is volatile |
| ); |
| |
| void set_method( // sets entry to resolved method entry |
| Bytecodes::Code invoke_code, // the bytecode used for invoking the method |
| methodHandle method, // the method/prototype if any (NULL, otherwise) |
| int vtable_index // the vtable index if any, else negative |
| ); |
| |
| void set_interface_call( |
| methodHandle method, // Resolved method |
| int index // Method index into interface |
| ); |
| |
| void set_parameter_size(int value) { |
| assert(parameter_size() == 0 || parameter_size() == value, |
| "size must not change"); |
| // Setting the parameter size by itself is only safe if the |
| // current value of _flags is 0, otherwise another thread may have |
| // updated it and we don't want to overwrite that value. Don't |
| // bother trying to update it once it's nonzero but always make |
| // sure that the final parameter size agrees with what was passed. |
| if (_flags == 0) { |
| Atomic::cmpxchg_ptr((value & 0xFF), &_flags, 0); |
| } |
| guarantee(parameter_size() == value, "size must not change"); |
| } |
| |
| // Which bytecode number (1 or 2) in the index field is valid for this bytecode? |
| // Returns -1 if neither is valid. |
| static int bytecode_number(Bytecodes::Code code) { |
| switch (code) { |
| case Bytecodes::_getstatic : // fall through |
| case Bytecodes::_getfield : // fall through |
| case Bytecodes::_invokespecial : // fall through |
| case Bytecodes::_invokestatic : // fall through |
| case Bytecodes::_invokeinterface : return 1; |
| case Bytecodes::_putstatic : // fall through |
| case Bytecodes::_putfield : // fall through |
| case Bytecodes::_invokevirtual : return 2; |
| default : break; |
| } |
| return -1; |
| } |
| |
| // Has this bytecode been resolved? Only valid for invokes and get/put field/static. |
| bool is_resolved(Bytecodes::Code code) const { |
| switch (bytecode_number(code)) { |
| case 1: return (bytecode_1() == code); |
| case 2: return (bytecode_2() == code); |
| } |
| return false; // default: not resolved |
| } |
| |
| // Accessors |
| int constant_pool_index() const { return _indices & 0xFFFF; } |
| Bytecodes::Code bytecode_1() const { return Bytecodes::cast((_indices >> 16) & 0xFF); } |
| Bytecodes::Code bytecode_2() const { return Bytecodes::cast((_indices >> 24) & 0xFF); } |
| volatile oop f1() const { return _f1; } |
| intx f2() const { return _f2; } |
| int field_index() const; |
| int parameter_size() const { return _flags & 0xFF; } |
| bool is_vfinal() const { return ((_flags & (1 << vfinalMethod)) == (1 << vfinalMethod)); } |
| bool is_volatile() const { return ((_flags & (1 << volatileField)) == (1 << volatileField)); } |
| bool is_methodInterface() const { return ((_flags & (1 << methodInterface)) == (1 << methodInterface)); } |
| bool is_byte() const { return (((uintx) _flags >> tosBits) == btos); } |
| bool is_char() const { return (((uintx) _flags >> tosBits) == ctos); } |
| bool is_short() const { return (((uintx) _flags >> tosBits) == stos); } |
| bool is_int() const { return (((uintx) _flags >> tosBits) == itos); } |
| bool is_long() const { return (((uintx) _flags >> tosBits) == ltos); } |
| bool is_float() const { return (((uintx) _flags >> tosBits) == ftos); } |
| bool is_double() const { return (((uintx) _flags >> tosBits) == dtos); } |
| bool is_object() const { return (((uintx) _flags >> tosBits) == atos); } |
| TosState flag_state() const { assert( ( (_flags >> tosBits) & 0x0F ) < number_of_states, "Invalid state in as_flags"); |
| return (TosState)((_flags >> tosBits) & 0x0F); } |
| |
| // Code generation support |
| static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); } |
| static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); } |
| static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); } |
| static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); } |
| static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); } |
| |
| // GC Support |
| void oops_do(void f(oop*)); |
| void oop_iterate(OopClosure* blk); |
| void oop_iterate_m(OopClosure* blk, MemRegion mr); |
| void follow_contents(); |
| void adjust_pointers(); |
| |
| #ifndef SERIALGC |
| // Parallel Old |
| void follow_contents(ParCompactionManager* cm); |
| #endif // SERIALGC |
| |
| void update_pointers(); |
| void update_pointers(HeapWord* beg_addr, HeapWord* end_addr); |
| |
| // RedefineClasses() API support: |
| // If this constantPoolCacheEntry refers to old_method then update it |
| // to refer to 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_method_entry(methodOop old_method, methodOop new_method, |
| bool * trace_name_printed); |
| bool is_interesting_method_entry(klassOop k); |
| bool is_field_entry() const { return (_flags & (1 << hotSwapBit)) == 0; } |
| bool is_method_entry() const { return (_flags & (1 << hotSwapBit)) != 0; } |
| |
| // Debugging & Printing |
| void print (outputStream* st, int index) const; |
| void verify(outputStream* st) const; |
| |
| static void verify_tosBits() { |
| assert(tosBits == 28, "interpreter now assumes tosBits is 28"); |
| } |
| }; |
| |
| |
| // A constant pool cache is a runtime data structure set aside to a constant pool. The cache |
| // holds interpreter runtime information for all field access and invoke bytecodes. The cache |
| // is created and initialized before a class is actively used (i.e., initialized), the indivi- |
| // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*). |
| |
| class constantPoolCacheOopDesc: public arrayOopDesc { |
| friend class VMStructs; |
| private: |
| constantPoolOop _constant_pool; // the corresponding constant pool |
| |
| // Sizing |
| static int header_size() { return sizeof(constantPoolCacheOopDesc) / HeapWordSize; } |
| static int object_size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); } |
| int object_size() { return object_size(length()); } |
| |
| // Helpers |
| constantPoolOop* constant_pool_addr() { return &_constant_pool; } |
| ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); } |
| |
| friend class constantPoolCacheKlass; |
| |
| public: |
| // Initialization |
| void initialize(intArray& inverse_index_map); |
| |
| // Accessors |
| void set_constant_pool(constantPoolOop pool) { oop_store_without_check((oop*)&_constant_pool, (oop)pool); } |
| constantPoolOop constant_pool() const { return _constant_pool; } |
| ConstantPoolCacheEntry* entry_at(int i) const { assert(0 <= i && i < length(), "index out of bounds"); return base() + i; } |
| |
| // Code generation |
| static ByteSize base_offset() { return in_ByteSize(sizeof(constantPoolCacheOopDesc)); } |
| |
| // RedefineClasses() API support: |
| // If any entry of this constantPoolCache 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(methodOop* old_methods, methodOop* new_methods, |
| int methods_length, bool * trace_name_printed); |
| }; |
