/* * Copyright (c) 1998, 2020, 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_OOPS_CPCACHE_HPP #define SHARE_OOPS_CPCACHE_HPP #include "interpreter/bytecodes.hpp" #include "memory/allocation.hpp" #include "oops/array.hpp" #include "oops/oopHandle.hpp" #include "runtime/handles.hpp" #include "utilities/align.hpp" #include "utilities/constantTag.hpp" #include "utilities/growableArray.hpp" class PSPromotionManager; // The ConstantPoolCache is not a cache! It is the resolution table that the // interpreter uses to avoid going into the runtime and a way to access resolved // values. // 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 ] index = constant_pool_index // _f1 [ entry specific ] metadata ptr (method or klass) // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr // _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries) // bit length [ 4 |1| 1 |1|1|1|1|1|1 |1 |-3-|----16-----] // _flags [tos|0|F=0|S|A|I|f|0|vf|indy_rf|000|00000|psize] (for method entries) // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--] // -------------------------------- // // with: // index = original constant pool index // b1 = bytecode 1 // b2 = bytecode 2 // psize = parameters size (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. // tos = TosState // F = the entry is for a field (or F=0 for a method) // A = call site has an appendix argument (loaded from resolved references) // I = interface call is forced virtual (must use a vtable index or vfinal) // f = field or method is final // v = field is volatile // vf = virtual but final (method entries only: is_vfinal()) // indy_rf = call site specifier method resolution failed // // The flags after TosState have the following interpretation: // bit 27: 0 for fields, 1 for methods // f flag true if field is marked final // v flag true if field is volatile (only for fields) // f2 flag true if f2 contains an oop (e.g., virtual final method) // fv flag true if invokeinterface used for method in class Object // // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 16 with the // following mapping to the TosState states: // // btos: 0 // ztos: 1 // ctos: 2 // stos: 3 // itos: 4 // ltos: 5 // ftos: 6 // dtos: 7 // atos: 8 // vtos: 9 // // Entry specific: field entries: // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index // _f1 = field holder (as a java.lang.Class, not a Klass*) // _f2 = field offset in bytes // _flags = field type information, original FieldInfo 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 non-virtual calls, unused by virtual calls. // for interface calls, which are essentially virtual but need a klass, // contains Klass* for the corresponding interface. // for invokedynamic and invokehandle, f1 contains the adapter method which // manages the actual call. The appendix is stored in the ConstantPool // resolved_references array. // (upcoming metadata changes will move the appendix to a separate array) // _f2 = vtable/itable index (or final Method*) for virtual calls only, // unused by non-virtual. The is_vfinal flag indicates this is a // method pointer for a final method, not an index. // _flags = has local signature (MHs and indy), // virtual final bit (vfinal), // parameter size (psize 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 CallInfo; class ConstantPoolCacheEntry { friend class VMStructs; friend class constantPoolCacheKlass; friend class ConstantPool; friend class InterpreterRuntime; private: volatile intx _indices; // constant pool index & rewrite bytecodes Metadata* volatile _f1; // entry specific metadata field volatile intx _f2; // entry specific int/metadata field volatile intx _flags; // flags void set_bytecode_1(Bytecodes::Code code); void set_bytecode_2(Bytecodes::Code code); void set_f1(Metadata* f1) { Metadata* existing_f1 = _f1; // read once assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change"); _f1 = f1; } void release_set_f1(Metadata* f1); void set_f2(intx f2) { intx existing_f2 = _f2; // read once assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change"); _f2 = f2; } void set_f2_as_vfinal_method(Method* f2) { assert(is_vfinal(), "flags must be set"); set_f2((intx)f2); } int make_flags(TosState state, int option_bits, int field_index_or_method_params); void set_flags(intx flags) { _flags = flags; } void set_field_flags(TosState field_type, int option_bits, int field_index) { assert((field_index & field_index_mask) == field_index, "field_index in range"); set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index)); } void set_method_flags(TosState return_type, int option_bits, int method_params) { assert((method_params & parameter_size_mask) == method_params, "method_params in range"); set_flags(make_flags(return_type, option_bits, method_params)); } public: // specific bit definitions for the flags field: // (Note: the interpreter must use these definitions to access the CP cache.) enum { // high order bits are the TosState corresponding to field type or method return type tos_state_bits = 4, tos_state_mask = right_n_bits(tos_state_bits), tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below // misc. option bits; can be any bit position in [16..27] is_field_entry_shift = 26, // (F) is it a field or a method? has_local_signature_shift = 25, // (S) does the call site have a per-site signature (sig-poly methods)? has_appendix_shift = 24, // (A) does the call site have an appendix argument? is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode? is_final_shift = 22, // (f) is the field or method final? is_volatile_shift = 21, // (v) is the field volatile? is_vfinal_shift = 20, // (vf) did the call resolve to a final method? indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ? // low order bits give field index (for FieldInfo) or method parameter size: field_index_bits = 16, field_index_mask = right_n_bits(field_index_bits), parameter_size_bits = 8, // subset of field_index_mask, range is 0..255 parameter_size_mask = right_n_bits(parameter_size_bits), option_bits_mask = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask)) }; // specific bit definitions for the indices field: enum { cp_index_bits = 2*BitsPerByte, cp_index_mask = right_n_bits(cp_index_bits), bytecode_1_shift = cp_index_bits, bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF bytecode_2_shift = cp_index_bits + BitsPerByte, bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF }; // Initialization void initialize_entry(int original_index); // initialize primary entry void initialize_resolved_reference_index(int ref_index) { assert(_f2 == 0, "set once"); // note: ref_index might be zero also _f2 = ref_index; } 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 Klass* 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 Klass* root_klass // needed by the GC to dirty the klass ); private: void set_direct_or_vtable_call( Bytecodes::Code invoke_code, // the bytecode used for invoking the method const methodHandle& method, // the method/prototype if any (NULL, otherwise) int vtable_index, // the vtable index if any, else negative bool sender_is_interface ); public: void set_direct_call( // sets entry to exact concrete method entry Bytecodes::Code invoke_code, // the bytecode used for invoking the method const methodHandle& method, // the method to call bool sender_is_interface ); void set_vtable_call( // sets entry to vtable index Bytecodes::Code invoke_code, // the bytecode used for invoking the method const methodHandle& method, // resolved method which declares the vtable index int vtable_index // the vtable index ); void set_itable_call( Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface Klass* referenced_klass, // the referenced klass in the InterfaceMethodref const methodHandle& method, // the resolved interface method int itable_index // index into itable for the method ); void set_method_handle( const constantPoolHandle& cpool, // holding constant pool (required for locking) const CallInfo &call_info // Call link information ); void set_dynamic_call( const constantPoolHandle& cpool, // holding constant pool (required for locking) const CallInfo &call_info // Call link information ); // Common code for invokedynamic and MH invocations. // The "appendix" is an optional call-site-specific parameter which is // pushed by the JVM at the end of the argument list. This argument may // be a MethodType for the MH.invokes and a CallSite for an invokedynamic // instruction. However, its exact type and use depends on the Java upcall, // which simply returns a compiled LambdaForm along with any reference // that LambdaForm needs to complete the call. If the upcall returns a // null appendix, the argument is not passed at all. // // The appendix is *not* represented in the signature of the symbolic // reference for the call site, but (if present) it *is* represented in // the Method* bound to the site. This means that static and dynamic // resolution logic needs to make slightly different assessments about the // number and types of arguments. void set_method_handle_common( const constantPoolHandle& cpool, // holding constant pool (required for locking) Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic const CallInfo &call_info // Call link information ); // Return TRUE if resolution failed and this thread got to record the failure // status. Return FALSE if another thread succeeded or failed in resolving // the method and recorded the success or failure before this thread had a // chance to record its failure. bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS); // invokedynamic and invokehandle call sites have an "appendix" item in the // resolved references array. Method* method_if_resolved(const constantPoolHandle& cpool); oop appendix_if_resolved(const constantPoolHandle& cpool); void set_parameter_size(int value); // 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::_invokehandle : // fall through case Bytecodes::_invokedynamic : // 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; // Accessors int indices() const { return _indices; } int indices_ord() const; int constant_pool_index() const { return (indices() & cp_index_mask); } Bytecodes::Code bytecode_1() const; Bytecodes::Code bytecode_2() const; Metadata* f1_ord() const; Method* f1_as_method() const; Klass* f1_as_klass() const; // Use the accessor f1() to acquire _f1's value. This is needed for // example in BytecodeInterpreter::run(), where is_f1_null() is // called to check if an invokedynamic call is resolved. This load // of _f1 must be ordered with the loads performed by // cache->main_entry_index(). bool is_f1_null() const; // classifies a CPC entry as unbound int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; } Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; } Method* f2_as_interface_method() const; intx flags_ord() const; int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); } int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); } bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; } bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; } bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; } bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; } bool indy_resolution_failed() const; bool has_appendix() const; bool has_local_signature() const; bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; } bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; } bool is_long() const { return flag_state() == ltos; } bool is_double() const { return flag_state() == dtos; } TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, ""); return (TosState)((_flags >> tos_state_shift) & tos_state_mask); } void set_indy_resolution_failed(); // Code generation support static WordSize size() { return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize); } static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); } 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); } #if INCLUDE_JVMTI // 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. void adjust_method_entry(Method* old_method, Method* new_method, bool* trace_name_printed); bool check_no_old_or_obsolete_entries(); Method* get_interesting_method_entry(); #endif // INCLUDE_JVMTI // Debugging & Printing void print (outputStream* st, int index) const; void verify(outputStream* st) const; static void verify_tos_state_shift() { // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state: assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask"); } void verify_just_initialized(bool f2_used); void reinitialize(bool f2_used); }; // 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 ConstantPoolCache: public MetaspaceObj { friend class VMStructs; friend class MetadataFactory; private: // If you add a new field that points to any metaspace object, you // must add this field to ConstantPoolCache::metaspace_pointers_do(). int _length; ConstantPool* _constant_pool; // the corresponding constant pool // The following fields need to be modified at runtime, so they cannot be // stored in the ConstantPool, which is read-only. // Array of resolved objects from the constant pool and map from resolved // object index to original constant pool index OopHandle _resolved_references; Array* _reference_map; // The narrowOop pointer to the archived resolved_references. Set at CDS dump // time when caching java heap object is supported. CDS_JAVA_HEAP_ONLY(int _archived_references_index;) // Sizing debug_only(friend class ClassVerifier;) // Constructor ConstantPoolCache(int length, const intStack& inverse_index_map, const intStack& invokedynamic_inverse_index_map, const intStack& invokedynamic_references_map); // Initialization void initialize(const intArray& inverse_index_map, const intArray& invokedynamic_inverse_index_map, const intArray& invokedynamic_references_map); public: static ConstantPoolCache* allocate(ClassLoaderData* loader_data, const intStack& cp_cache_map, const intStack& invokedynamic_cp_cache_map, const intStack& invokedynamic_references_map, TRAPS); int length() const { return _length; } void metaspace_pointers_do(MetaspaceClosure* it); MetaspaceObj::Type type() const { return ConstantPoolCacheType; } oop archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL); void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN; void clear_archived_references() NOT_CDS_JAVA_HEAP_RETURN; inline oop resolved_references(); void set_resolved_references(OopHandle s) { _resolved_references = s; } Array* reference_map() const { return _reference_map; } void set_reference_map(Array* o) { _reference_map = o; } // Assembly code support static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); } // CDS support void remove_unshareable_info(); void verify_just_initialized(); private: void walk_entries_for_initialization(bool check_only); void set_length(int length) { _length = length; } static int header_size() { return sizeof(ConstantPoolCache) / wordSize; } static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); } public: int size() const { return size(length()); } private: // Helpers ConstantPool** constant_pool_addr() { return &_constant_pool; } ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); } friend class constantPoolCacheKlass; friend class ConstantPoolCacheEntry; public: // Accessors void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; } ConstantPool* constant_pool() const { return _constant_pool; } // Fetches the entry at the given index. // In either case the index must not be encoded or byte-swapped in any way. 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(ConstantPoolCache)); } static ByteSize entry_offset(int raw_index) { int index = raw_index; return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index); } #if INCLUDE_JVMTI // 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(bool* trace_name_printed); bool check_no_old_or_obsolete_entries(); void dump_cache(); #endif // INCLUDE_JVMTI // RedefineClasses support DEBUG_ONLY(bool on_stack() { return false; }) void deallocate_contents(ClassLoaderData* data); bool is_klass() const { return false; } // Printing void print_on(outputStream* st) const; void print_value_on(outputStream* st) const; const char* internal_name() const { return "{constant pool cache}"; } // Verify void verify_on(outputStream* st); }; #endif // SHARE_OOPS_CPCACHE_HPP