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src/hotspot/share/oops/oop.hpp

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*** 26,45 **** --- 26,82 ---- #define SHARE_OOPS_OOP_HPP #include "memory/iterator.hpp" #include "memory/memRegion.hpp" #include "oops/access.hpp" + #include "oops/arrayStorageProperties.hpp" #include "oops/metadata.hpp" #include "runtime/atomic.hpp" #include "utilities/macros.hpp" // oopDesc is the top baseclass for objects classes. The {name}Desc classes describe // the format of Java objects so the fields can be accessed from C++. // oopDesc is abstract. // (see oopHierarchy for complete oop class hierarchy) // // no virtual functions allowed + // + // oopDesc::_mark - the "oop mark word" encoding to be found separately in markOop.hpp + // + // oopDesc::_metadata - encodes both the object's klass pointer and potentially + // "storage properties" (currently confined to arrays in the form of + // ArrayStorageProperties). Storage properties are peculiar to the + // *instance*, and not necessarily the "type". + // + // The overall size of the _metadata field is dependent on "UseCompressedClassPointers", + // hence the terms "narrow" (32 bits) vs "wide" (64 bits). + // + // "Wide" encoding of _metadata: + // bit number |63 0| + // bit length |--3|-----61-----| + // -------------------------------------- + // _klass [xxx| Klass* ] + // _wide_storage_props [ sp| ] + // -------------------------------------- + // with: + // xxx = klass_mask(), Klass* = Klass pointer to be masked + // sp = storage properties, bit number: wide_storage_props_shift + // + // "Narrow" encoding of _metadata: + // bit number |31 0| + // bit length |--3|-----29-----| + // ---------------------------------------- + // _compressed_klass [xxx| narrowKlass] + // _narrow_storage_props [ sp| ] + // ---------------------------------------- + // with: + // xxx = compressed_klass_mask(), narrowKlass = compressed Klass pointer to be masked + // narrowKlass may be further decoded (Klass::decode_klass()) to produce Klass* + // sp = storage properties, bit number: narrow_storage_props_shift + // + // Storage properties encodings are current confined to arrayStorageProperties.hpp + extern bool always_do_update_barrier; // Forward declarations. class OopClosure;
*** 57,66 **** --- 94,105 ---- private: volatile markOop _mark; union _metadata { Klass* _klass; narrowKlass _compressed_klass; + uintptr_t _wide_storage_props; + uint32_t _narrow_storage_props; } _metadata; public: inline markOop mark() const; inline markOop mark_raw() const;
*** 77,86 **** --- 116,136 ---- // Used only to re-initialize the mark word (e.g., of promoted // objects during a GC) -- requires a valid klass pointer inline void init_mark(); inline void init_mark_raw(); + enum { + storage_props_nof_bits = LogKlassAlignmentInBytes, // This alignment gives us some "free bits" + narrow_storage_props_shift = (sizeof(narrowKlass) << 3) - storage_props_nof_bits, + wide_storage_props_shift = (sizeof(Klass*) << 3) - storage_props_nof_bits + }; + + static inline narrowKlass compressed_klass_mask(); + static inline narrowKlass compressed_klass_masked(narrowKlass raw); + static inline uintptr_t klass_mask(); + static inline Klass* klass_masked(uintptr_t raw); + inline Klass* klass() const; inline Klass* klass_or_null() const volatile; inline Klass* klass_or_null_acquire() const volatile; static inline Klass** klass_addr(HeapWord* mem); static inline narrowKlass* compressed_klass_addr(HeapWord* mem);
*** 88,97 **** --- 138,154 ---- inline narrowKlass* compressed_klass_addr(); inline void set_klass(Klass* k); static inline void release_set_klass(HeapWord* mem, Klass* klass); + // Extra container metadata specific to arrays (encoded into high bits of _metadata) + static inline uintptr_t* wide_metadata_addr(HeapWord* mem); + inline ArrayStorageProperties array_storage_properties() const; + inline void set_metadata(ArrayStorageProperties storage_props, Klass* k); + static inline void release_set_metadata(HeapWord* mem, ArrayStorageProperties storage_props, Klass* klass); + + // For klass field compression inline int klass_gap() const; inline void set_klass_gap(int z); static inline void set_klass_gap(HeapWord* mem, int z); // For when the klass pointer is being used as a linked list "next" field.
*** 114,129 **** --- 171,190 ---- // type test operations (inlined in oop.inline.hpp) inline bool is_instance() const; inline bool is_array() const; inline bool is_objArray() const; inline bool is_typeArray() const; + inline bool is_value() const; + inline bool is_valueArray() const; // type test operations that don't require inclusion of oop.inline.hpp. bool is_instance_noinline() const; bool is_array_noinline() const; bool is_objArray_noinline() const; bool is_typeArray_noinline() const; + bool is_value_noinline() const; + bool is_valueArray_noinline() const; protected: inline oop as_oop() const { return const_cast<oopDesc*>(this); } public:
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