| /* |
| * Copyright (c) 1997, 2013, 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_KLASS_HPP |
| #define SHARE_VM_OOPS_KLASS_HPP |
| |
| #include "memory/genOopClosures.hpp" |
| #include "memory/iterator.hpp" |
| #include "memory/memRegion.hpp" |
| #include "memory/specialized_oop_closures.hpp" |
| #include "oops/klassPS.hpp" |
| #include "oops/metadata.hpp" |
| #include "oops/oop.hpp" |
| #include "runtime/orderAccess.hpp" |
| #include "trace/traceMacros.hpp" |
| #include "utilities/accessFlags.hpp" |
| #include "utilities/macros.hpp" |
| #if INCLUDE_ALL_GCS |
| #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp" |
| #include "gc_implementation/g1/g1OopClosures.hpp" |
| #include "gc_implementation/parNew/parOopClosures.hpp" |
| #endif // INCLUDE_ALL_GCS |
| |
| // |
| // A Klass provides: |
| // 1: language level class object (method dictionary etc.) |
| // 2: provide vm dispatch behavior for the object |
| // Both functions are combined into one C++ class. |
| |
| // One reason for the oop/klass dichotomy in the implementation is |
| // that we don't want a C++ vtbl pointer in every object. Thus, |
| // normal oops don't have any virtual functions. Instead, they |
| // forward all "virtual" functions to their klass, which does have |
| // a vtbl and does the C++ dispatch depending on the object's |
| // actual type. (See oop.inline.hpp for some of the forwarding code.) |
| // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! |
| |
| // Klass layout: |
| // [C++ vtbl ptr ] (contained in Metadata) |
| // [layout_helper ] |
| // [super_check_offset ] for fast subtype checks |
| // [name ] |
| // [secondary_super_cache] for fast subtype checks |
| // [secondary_supers ] array of 2ndary supertypes |
| // [primary_supers 0] |
| // [primary_supers 1] |
| // [primary_supers 2] |
| // ... |
| // [primary_supers 7] |
| // [java_mirror ] |
| // [super ] |
| // [subklass ] first subclass |
| // [next_sibling ] link to chain additional subklasses |
| // [next_link ] |
| // [class_loader_data] |
| // [modifier_flags] |
| // [access_flags ] |
| // [last_biased_lock_bulk_revocation_time] (64 bits) |
| // [prototype_header] |
| // [biased_lock_revocation_count] |
| // [_modified_oops] |
| // [_accumulated_modified_oops] |
| // [trace_id] |
| |
| |
| // Forward declarations. |
| template <class T> class Array; |
| template <class T> class GrowableArray; |
| class ClassLoaderData; |
| class klassVtable; |
| class ParCompactionManager; |
| class KlassSizeStats; |
| |
| class Klass : public Metadata { |
| friend class VMStructs; |
| protected: |
| // note: put frequently-used fields together at start of klass structure |
| // for better cache behavior (may not make much of a difference but sure won't hurt) |
| enum { _primary_super_limit = 8 }; |
| |
| // The "layout helper" is a combined descriptor of object layout. |
| // For klasses which are neither instance nor array, the value is zero. |
| // |
| // For instances, layout helper is a positive number, the instance size. |
| // This size is already passed through align_object_size and scaled to bytes. |
| // The low order bit is set if instances of this class cannot be |
| // allocated using the fastpath. |
| // |
| // For arrays, layout helper is a negative number, containing four |
| // distinct bytes, as follows: |
| // MSB:[tag, hsz, ebt, log2(esz)]:LSB |
| // where: |
| // tag is 0x80 if the elements are oops, 0xC0 if non-oops |
| // hsz is array header size in bytes (i.e., offset of first element) |
| // ebt is the BasicType of the elements |
| // esz is the element size in bytes |
| // This packed word is arranged so as to be quickly unpacked by the |
| // various fast paths that use the various subfields. |
| // |
| // The esz bits can be used directly by a SLL instruction, without masking. |
| // |
| // Note that the array-kind tag looks like 0x00 for instance klasses, |
| // since their length in bytes is always less than 24Mb. |
| // |
| // Final note: This comes first, immediately after C++ vtable, |
| // because it is frequently queried. |
| jint _layout_helper; |
| |
| // The fields _super_check_offset, _secondary_super_cache, _secondary_supers |
| // and _primary_supers all help make fast subtype checks. See big discussion |
| // in doc/server_compiler/checktype.txt |
| // |
| // Where to look to observe a supertype (it is &_secondary_super_cache for |
| // secondary supers, else is &_primary_supers[depth()]. |
| juint _super_check_offset; |
| |
| // Class name. Instance classes: java/lang/String, etc. Array classes: [I, |
| // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. |
| Symbol* _name; |
| |
| // Cache of last observed secondary supertype |
| Klass* _secondary_super_cache; |
| // Array of all secondary supertypes |
| Array<Klass*>* _secondary_supers; |
| // Ordered list of all primary supertypes |
| Klass* _primary_supers[_primary_super_limit]; |
| // java/lang/Class instance mirroring this class |
| oop _java_mirror; |
| // Superclass |
| Klass* _super; |
| // First subclass (NULL if none); _subklass->next_sibling() is next one |
| Klass* _subklass; |
| // Sibling link (or NULL); links all subklasses of a klass |
| Klass* _next_sibling; |
| |
| // All klasses loaded by a class loader are chained through these links |
| Klass* _next_link; |
| |
| // The VM's representation of the ClassLoader used to load this class. |
| // Provide access the corresponding instance java.lang.ClassLoader. |
| ClassLoaderData* _class_loader_data; |
| |
| jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. |
| AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. |
| |
| // Biased locking implementation and statistics |
| // (the 64-bit chunk goes first, to avoid some fragmentation) |
| jlong _last_biased_lock_bulk_revocation_time; |
| markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type |
| jint _biased_lock_revocation_count; |
| |
| TRACE_DEFINE_KLASS_TRACE_ID; |
| |
| // Remembered sets support for the oops in the klasses. |
| jbyte _modified_oops; // Card Table Equivalent (YC/CMS support) |
| jbyte _accumulated_modified_oops; // Mod Union Equivalent (CMS support) |
| |
| // Constructor |
| Klass(); |
| |
| void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw(); |
| |
| public: |
| bool is_klass() const volatile { return true; } |
| |
| // super |
| Klass* super() const { return _super; } |
| void set_super(Klass* k) { _super = k; } |
| |
| // initializes _super link, _primary_supers & _secondary_supers arrays |
| void initialize_supers(Klass* k, TRAPS); |
| void initialize_supers_impl1(Klass* k); |
| void initialize_supers_impl2(Klass* k); |
| |
| // klass-specific helper for initializing _secondary_supers |
| virtual GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots); |
| |
| // java_super is the Java-level super type as specified by Class.getSuperClass. |
| virtual Klass* java_super() const { return NULL; } |
| |
| juint super_check_offset() const { return _super_check_offset; } |
| void set_super_check_offset(juint o) { _super_check_offset = o; } |
| |
| Klass* secondary_super_cache() const { return _secondary_super_cache; } |
| void set_secondary_super_cache(Klass* k) { _secondary_super_cache = k; } |
| |
| Array<Klass*>* secondary_supers() const { return _secondary_supers; } |
| void set_secondary_supers(Array<Klass*>* k) { _secondary_supers = k; } |
| |
| // Return the element of the _super chain of the given depth. |
| // If there is no such element, return either NULL or this. |
| Klass* primary_super_of_depth(juint i) const { |
| assert(i < primary_super_limit(), "oob"); |
| Klass* super = _primary_supers[i]; |
| assert(super == NULL || super->super_depth() == i, "correct display"); |
| return super; |
| } |
| |
| // Can this klass be a primary super? False for interfaces and arrays of |
| // interfaces. False also for arrays or classes with long super chains. |
| bool can_be_primary_super() const { |
| const juint secondary_offset = in_bytes(secondary_super_cache_offset()); |
| return super_check_offset() != secondary_offset; |
| } |
| virtual bool can_be_primary_super_slow() const; |
| |
| // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. |
| juint super_depth() const { |
| if (!can_be_primary_super()) { |
| return primary_super_limit(); |
| } else { |
| juint d = (super_check_offset() - in_bytes(primary_supers_offset())) / sizeof(Klass*); |
| assert(d < primary_super_limit(), "oob"); |
| assert(_primary_supers[d] == this, "proper init"); |
| return d; |
| } |
| } |
| |
| // store an oop into a field of a Klass |
| void klass_oop_store(oop* p, oop v); |
| void klass_oop_store(volatile oop* p, oop v); |
| |
| // java mirror |
| oop java_mirror() const { return _java_mirror; } |
| void set_java_mirror(oop m) { klass_oop_store(&_java_mirror, m); } |
| |
| // modifier flags |
| jint modifier_flags() const { return _modifier_flags; } |
| void set_modifier_flags(jint flags) { _modifier_flags = flags; } |
| |
| // size helper |
| int layout_helper() const { return _layout_helper; } |
| void set_layout_helper(int lh) { _layout_helper = lh; } |
| |
| // Note: for instances layout_helper() may include padding. |
| // Use InstanceKlass::contains_field_offset to classify field offsets. |
| |
| // sub/superklass links |
| InstanceKlass* superklass() const; |
| Klass* subklass() const; |
| Klass* next_sibling() const; |
| void append_to_sibling_list(); // add newly created receiver to superklass' subklass list |
| |
| void set_next_link(Klass* k) { _next_link = k; } |
| Klass* next_link() const { return _next_link; } // The next klass defined by the class loader. |
| |
| // class loader data |
| ClassLoaderData* class_loader_data() const { return _class_loader_data; } |
| void set_class_loader_data(ClassLoaderData* loader_data) { _class_loader_data = loader_data; } |
| |
| // The Klasses are not placed in the Heap, so the Card Table or |
| // the Mod Union Table can't be used to mark when klasses have modified oops. |
| // The CT and MUT bits saves this information for the individual Klasses. |
| void record_modified_oops() { _modified_oops = 1; } |
| void clear_modified_oops() { _modified_oops = 0; } |
| bool has_modified_oops() { return _modified_oops == 1; } |
| |
| void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = 1; } |
| void clear_accumulated_modified_oops() { _accumulated_modified_oops = 0; } |
| bool has_accumulated_modified_oops() { return _accumulated_modified_oops == 1; } |
| |
| protected: // internal accessors |
| Klass* subklass_oop() const { return _subklass; } |
| Klass* next_sibling_oop() const { return _next_sibling; } |
| void set_subklass(Klass* s); |
| void set_next_sibling(Klass* s); |
| |
| public: |
| |
| // Compiler support |
| static ByteSize super_offset() { return in_ByteSize(offset_of(Klass, _super)); } |
| static ByteSize super_check_offset_offset() { return in_ByteSize(offset_of(Klass, _super_check_offset)); } |
| static ByteSize primary_supers_offset() { return in_ByteSize(offset_of(Klass, _primary_supers)); } |
| static ByteSize secondary_super_cache_offset() { return in_ByteSize(offset_of(Klass, _secondary_super_cache)); } |
| static ByteSize secondary_supers_offset() { return in_ByteSize(offset_of(Klass, _secondary_supers)); } |
| static ByteSize java_mirror_offset() { return in_ByteSize(offset_of(Klass, _java_mirror)); } |
| static ByteSize modifier_flags_offset() { return in_ByteSize(offset_of(Klass, _modifier_flags)); } |
| static ByteSize layout_helper_offset() { return in_ByteSize(offset_of(Klass, _layout_helper)); } |
| static ByteSize access_flags_offset() { return in_ByteSize(offset_of(Klass, _access_flags)); } |
| |
| // Unpacking layout_helper: |
| enum { |
| _lh_neutral_value = 0, // neutral non-array non-instance value |
| _lh_instance_slow_path_bit = 0x01, |
| _lh_log2_element_size_shift = BitsPerByte*0, |
| _lh_log2_element_size_mask = BitsPerLong-1, |
| _lh_element_type_shift = BitsPerByte*1, |
| _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask |
| _lh_header_size_shift = BitsPerByte*2, |
| _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask |
| _lh_array_tag_bits = 2, |
| _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, |
| _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 |
| _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 |
| }; |
| |
| static int layout_helper_size_in_bytes(jint lh) { |
| assert(lh > (jint)_lh_neutral_value, "must be instance"); |
| return (int) lh & ~_lh_instance_slow_path_bit; |
| } |
| static bool layout_helper_needs_slow_path(jint lh) { |
| assert(lh > (jint)_lh_neutral_value, "must be instance"); |
| return (lh & _lh_instance_slow_path_bit) != 0; |
| } |
| static bool layout_helper_is_instance(jint lh) { |
| return (jint)lh > (jint)_lh_neutral_value; |
| } |
| static bool layout_helper_is_array(jint lh) { |
| return (jint)lh < (jint)_lh_neutral_value; |
| } |
| static bool layout_helper_is_typeArray(jint lh) { |
| // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); |
| return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift); |
| } |
| static bool layout_helper_is_objArray(jint lh) { |
| // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); |
| return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift); |
| } |
| static int layout_helper_header_size(jint lh) { |
| assert(lh < (jint)_lh_neutral_value, "must be array"); |
| int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; |
| assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); |
| return hsize; |
| } |
| static BasicType layout_helper_element_type(jint lh) { |
| assert(lh < (jint)_lh_neutral_value, "must be array"); |
| int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; |
| assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); |
| return (BasicType) btvalue; |
| } |
| static int layout_helper_log2_element_size(jint lh) { |
| assert(lh < (jint)_lh_neutral_value, "must be array"); |
| int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; |
| assert(l2esz <= LogBitsPerLong, |
| err_msg("sanity. l2esz: 0x%x for lh: 0x%x", (uint)l2esz, (uint)lh)); |
| return l2esz; |
| } |
| static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { |
| return (tag << _lh_array_tag_shift) |
| | (hsize << _lh_header_size_shift) |
| | ((int)etype << _lh_element_type_shift) |
| | (log2_esize << _lh_log2_element_size_shift); |
| } |
| static jint instance_layout_helper(jint size, bool slow_path_flag) { |
| return (size << LogHeapWordSize) |
| | (slow_path_flag ? _lh_instance_slow_path_bit : 0); |
| } |
| static int layout_helper_to_size_helper(jint lh) { |
| assert(lh > (jint)_lh_neutral_value, "must be instance"); |
| // Note that the following expression discards _lh_instance_slow_path_bit. |
| return lh >> LogHeapWordSize; |
| } |
| // Out-of-line version computes everything based on the etype: |
| static jint array_layout_helper(BasicType etype); |
| |
| // What is the maximum number of primary superclasses any klass can have? |
| #ifdef PRODUCT |
| static juint primary_super_limit() { return _primary_super_limit; } |
| #else |
| static juint primary_super_limit() { |
| assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); |
| return FastSuperclassLimit; |
| } |
| #endif |
| |
| // vtables |
| virtual klassVtable* vtable() const { return NULL; } |
| virtual int vtable_length() const { return 0; } |
| |
| // subclass check |
| bool is_subclass_of(const Klass* k) const; |
| // subtype check: true if is_subclass_of, or if k is interface and receiver implements it |
| bool is_subtype_of(Klass* k) const { |
| juint off = k->super_check_offset(); |
| Klass* sup = *(Klass**)( (address)this + off ); |
| const juint secondary_offset = in_bytes(secondary_super_cache_offset()); |
| if (sup == k) { |
| return true; |
| } else if (off != secondary_offset) { |
| return false; |
| } else { |
| return search_secondary_supers(k); |
| } |
| } |
| bool search_secondary_supers(Klass* k) const; |
| |
| // Find LCA in class hierarchy |
| Klass *LCA( Klass *k ); |
| |
| // Check whether reflection/jni/jvm code is allowed to instantiate this class; |
| // if not, throw either an Error or an Exception. |
| virtual void check_valid_for_instantiation(bool throwError, TRAPS); |
| |
| // array copying |
| virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); |
| |
| // tells if the class should be initialized |
| virtual bool should_be_initialized() const { return false; } |
| // initializes the klass |
| virtual void initialize(TRAPS); |
| // lookup operation for MethodLookupCache |
| friend class MethodLookupCache; |
| virtual Method* uncached_lookup_method(Symbol* name, Symbol* signature) const; |
| public: |
| Method* lookup_method(Symbol* name, Symbol* signature) const { |
| return uncached_lookup_method(name, signature); |
| } |
| |
| // array class with specific rank |
| Klass* array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } |
| |
| // array class with this klass as element type |
| Klass* array_klass(TRAPS) { return array_klass_impl(false, THREAD); } |
| |
| // These will return NULL instead of allocating on the heap: |
| // NB: these can block for a mutex, like other functions with TRAPS arg. |
| Klass* array_klass_or_null(int rank); |
| Klass* array_klass_or_null(); |
| |
| virtual oop protection_domain() const = 0; |
| |
| oop class_loader() const; |
| |
| virtual oop klass_holder() const { return class_loader(); } |
| |
| protected: |
| virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS); |
| virtual Klass* array_klass_impl(bool or_null, TRAPS); |
| |
| public: |
| // CDS support - remove and restore oops from metadata. Oops are not shared. |
| virtual void remove_unshareable_info(); |
| virtual void restore_unshareable_info(TRAPS); |
| |
| protected: |
| // computes the subtype relationship |
| virtual bool compute_is_subtype_of(Klass* k); |
| public: |
| // subclass accessor (here for convenience; undefined for non-klass objects) |
| virtual bool is_leaf_class() const { fatal("not a class"); return false; } |
| public: |
| // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP |
| // These functions describe behavior for the oop not the KLASS. |
| |
| // actual oop size of obj in memory |
| virtual int oop_size(oop obj) const = 0; |
| |
| // Size of klass in word size. |
| virtual int size() const = 0; |
| #if INCLUDE_SERVICES |
| virtual void collect_statistics(KlassSizeStats *sz) const; |
| #endif |
| |
| // Returns the Java name for a class (Resource allocated) |
| // For arrays, this returns the name of the element with a leading '['. |
| // For classes, this returns the name with the package separators |
| // turned into '.'s. |
| const char* external_name() const; |
| // Returns the name for a class (Resource allocated) as the class |
| // would appear in a signature. |
| // For arrays, this returns the name of the element with a leading '['. |
| // For classes, this returns the name with a leading 'L' and a trailing ';' |
| // and the package separators as '/'. |
| virtual const char* signature_name() const; |
| |
| // garbage collection support |
| virtual void oop_follow_contents(oop obj) = 0; |
| virtual int oop_adjust_pointers(oop obj) = 0; |
| |
| // Parallel Scavenge and Parallel Old |
| PARALLEL_GC_DECLS_PV |
| |
| // type testing operations |
| protected: |
| virtual bool oop_is_instance_slow() const { return false; } |
| virtual bool oop_is_array_slow() const { return false; } |
| virtual bool oop_is_objArray_slow() const { return false; } |
| virtual bool oop_is_typeArray_slow() const { return false; } |
| public: |
| virtual bool oop_is_instanceMirror() const { return false; } |
| virtual bool oop_is_instanceRef() const { return false; } |
| |
| // Fast non-virtual versions |
| #ifndef ASSERT |
| #define assert_same_query(xval, xcheck) xval |
| #else |
| private: |
| static bool assert_same_query(bool xval, bool xslow) { |
| assert(xval == xslow, "slow and fast queries agree"); |
| return xval; |
| } |
| public: |
| #endif |
| inline bool oop_is_instance() const { return assert_same_query( |
| layout_helper_is_instance(layout_helper()), |
| oop_is_instance_slow()); } |
| inline bool oop_is_array() const { return assert_same_query( |
| layout_helper_is_array(layout_helper()), |
| oop_is_array_slow()); } |
| inline bool oop_is_objArray() const { return assert_same_query( |
| layout_helper_is_objArray(layout_helper()), |
| oop_is_objArray_slow()); } |
| inline bool oop_is_typeArray() const { return assert_same_query( |
| layout_helper_is_typeArray(layout_helper()), |
| oop_is_typeArray_slow()); } |
| #undef assert_same_query |
| |
| // Access flags |
| AccessFlags access_flags() const { return _access_flags; } |
| void set_access_flags(AccessFlags flags) { _access_flags = flags; } |
| |
| bool is_public() const { return _access_flags.is_public(); } |
| bool is_final() const { return _access_flags.is_final(); } |
| bool is_interface() const { return _access_flags.is_interface(); } |
| bool is_abstract() const { return _access_flags.is_abstract(); } |
| bool is_super() const { return _access_flags.is_super(); } |
| bool is_synthetic() const { return _access_flags.is_synthetic(); } |
| void set_is_synthetic() { _access_flags.set_is_synthetic(); } |
| bool has_finalizer() const { return _access_flags.has_finalizer(); } |
| bool has_final_method() const { return _access_flags.has_final_method(); } |
| void set_has_finalizer() { _access_flags.set_has_finalizer(); } |
| void set_has_final_method() { _access_flags.set_has_final_method(); } |
| bool is_cloneable() const { return _access_flags.is_cloneable(); } |
| void set_is_cloneable() { _access_flags.set_is_cloneable(); } |
| bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } |
| void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } |
| bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } |
| void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } |
| |
| // Biased locking support |
| // Note: the prototype header is always set up to be at least the |
| // prototype markOop. If biased locking is enabled it may further be |
| // biasable and have an epoch. |
| markOop prototype_header() const { return _prototype_header; } |
| // NOTE: once instances of this klass are floating around in the |
| // system, this header must only be updated at a safepoint. |
| // NOTE 2: currently we only ever set the prototype header to the |
| // biasable prototype for instanceKlasses. There is no technical |
| // reason why it could not be done for arrayKlasses aside from |
| // wanting to reduce the initial scope of this optimization. There |
| // are potential problems in setting the bias pattern for |
| // JVM-internal oops. |
| inline void set_prototype_header(markOop header); |
| static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); } |
| |
| int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } |
| // Atomically increments biased_lock_revocation_count and returns updated value |
| int atomic_incr_biased_lock_revocation_count(); |
| void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } |
| jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } |
| void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } |
| |
| TRACE_DEFINE_KLASS_METHODS; |
| |
| // garbage collection support |
| virtual void oops_do(OopClosure* cl); |
| |
| // Iff the class loader (or mirror for anonymous classes) is alive the |
| // Klass is considered alive. |
| // The is_alive closure passed in depends on the Garbage Collector used. |
| bool is_loader_alive(BoolObjectClosure* is_alive); |
| |
| static void clean_weak_klass_links(BoolObjectClosure* is_alive); |
| |
| // Prefetch within oop iterators. This is a macro because we |
| // can't guarantee that the compiler will inline it. In 64-bit |
| // it generally doesn't. Signature is |
| // |
| // static void prefetch_beyond(oop* const start, |
| // oop* const end, |
| // const intx foffset, |
| // const Prefetch::style pstyle); |
| #define prefetch_beyond(start, end, foffset, pstyle) { \ |
| const intx foffset_ = (foffset); \ |
| const Prefetch::style pstyle_ = (pstyle); \ |
| assert(foffset_ > 0, "prefetch beyond, not behind"); \ |
| if (pstyle_ != Prefetch::do_none) { \ |
| oop* ref = (start); \ |
| if (ref < (end)) { \ |
| switch (pstyle_) { \ |
| case Prefetch::do_read: \ |
| Prefetch::read(*ref, foffset_); \ |
| break; \ |
| case Prefetch::do_write: \ |
| Prefetch::write(*ref, foffset_); \ |
| break; \ |
| default: \ |
| ShouldNotReachHere(); \ |
| break; \ |
| } \ |
| } \ |
| } \ |
| } |
| |
| // iterators |
| virtual int oop_oop_iterate(oop obj, ExtendedOopClosure* blk) = 0; |
| virtual int oop_oop_iterate_v(oop obj, ExtendedOopClosure* blk) { |
| return oop_oop_iterate(obj, blk); |
| } |
| |
| #if INCLUDE_ALL_GCS |
| // In case we don't have a specialized backward scanner use forward |
| // iteration. |
| virtual int oop_oop_iterate_backwards_v(oop obj, ExtendedOopClosure* blk) { |
| return oop_oop_iterate_v(obj, blk); |
| } |
| #endif // INCLUDE_ALL_GCS |
| |
| // Iterates "blk" over all the oops in "obj" (of type "this") within "mr". |
| // (I don't see why the _m should be required, but without it the Solaris |
| // C++ gives warning messages about overridings of the "oop_oop_iterate" |
| // defined above "hiding" this virtual function. (DLD, 6/20/00)) */ |
| virtual int oop_oop_iterate_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) = 0; |
| virtual int oop_oop_iterate_v_m(oop obj, ExtendedOopClosure* blk, MemRegion mr) { |
| return oop_oop_iterate_m(obj, blk, mr); |
| } |
| |
| // Versions of the above iterators specialized to particular subtypes |
| // of OopClosure, to avoid closure virtual calls. |
| #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ |
| virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \ |
| /* Default implementation reverts to general version. */ \ |
| return oop_oop_iterate(obj, blk); \ |
| } \ |
| \ |
| /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \ |
| (I don't see why the _m should be required, but without it the Solaris \ |
| C++ gives warning messages about overridings of the "oop_oop_iterate" \ |
| defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \ |
| virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \ |
| OopClosureType* blk, \ |
| MemRegion mr) { \ |
| return oop_oop_iterate_m(obj, blk, mr); \ |
| } |
| |
| SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) |
| SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) |
| |
| #if INCLUDE_ALL_GCS |
| #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ |
| virtual int oop_oop_iterate_backwards##nv_suffix(oop obj, \ |
| OopClosureType* blk) { \ |
| /* Default implementation reverts to general version. */ \ |
| return oop_oop_iterate_backwards_v(obj, blk); \ |
| } |
| |
| SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) |
| SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) |
| #endif // INCLUDE_ALL_GCS |
| |
| virtual void array_klasses_do(void f(Klass* k)) {} |
| |
| // Return self, except for abstract classes with exactly 1 |
| // implementor. Then return the 1 concrete implementation. |
| Klass *up_cast_abstract(); |
| |
| // klass name |
| Symbol* name() const { return _name; } |
| void set_name(Symbol* n); |
| |
| public: |
| // jvm support |
| virtual jint compute_modifier_flags(TRAPS) const; |
| |
| // JVMTI support |
| virtual jint jvmti_class_status() const; |
| |
| // Printing |
| virtual void print_on(outputStream* st) const; |
| |
| virtual void oop_print_value_on(oop obj, outputStream* st); |
| virtual void oop_print_on (oop obj, outputStream* st); |
| |
| virtual const char* internal_name() const = 0; |
| |
| // Verification |
| virtual void verify_on(outputStream* st, bool check_dictionary); |
| void verify(bool check_dictionary = true) { verify_on(tty, check_dictionary); } |
| |
| #ifndef PRODUCT |
| bool verify_vtable_index(int index); |
| bool verify_itable_index(int index); |
| #endif |
| |
| virtual void oop_verify_on(oop obj, outputStream* st); |
| |
| static bool is_null(narrowKlass obj); |
| static bool is_null(Klass* obj); |
| |
| // klass encoding for klass pointer in objects. |
| static narrowKlass encode_klass_not_null(Klass* v); |
| static narrowKlass encode_klass(Klass* v); |
| |
| static Klass* decode_klass_not_null(narrowKlass v); |
| static Klass* decode_klass(narrowKlass v); |
| |
| private: |
| // barriers used by klass_oop_store |
| void klass_update_barrier_set(oop v); |
| void klass_update_barrier_set_pre(void* p, oop v); |
| }; |
| |
| #endif // SHARE_VM_OOPS_KLASS_HPP |