/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
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* published by the Free Software Foundation.
*
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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#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/klassOop.hpp"
#include "oops/klassPS.hpp"
#include "oops/oop.hpp"
#include "runtime/orderAccess.hpp"
#include "trace/traceMacros.hpp"
#include "utilities/accessFlags.hpp"
#ifndef SERIALGC
#include "gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp"
#include "gc_implementation/g1/g1OopClosures.hpp"
#include "gc_implementation/parNew/parOopClosures.hpp"
#endif
// A Klass is the part of the klassOop that 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. The toplevel class "Klass"
// implements purpose 1 whereas all subclasses provide extra virtual functions
// for purpose 2.
// 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:
// [header ] klassOop
// [klass pointer ] klassOop
// [C++ vtbl ptr ] (contained in Klass_vtbl)
// [layout_helper ]
// [super_check_offset ] for fast subtype checks
// [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 ]
// [name ]
// [first subklass]
// [next_sibling ] link to chain additional subklasses
// [modifier_flags]
// [access_flags ]
// [verify_count ] - not in product
// [alloc_count ]
// [last_biased_lock_bulk_revocation_time] (64 bits)
// [prototype_header]
// [biased_lock_revocation_count]
// [trace_id]
// Forward declarations.
class klassVtable;
class KlassHandle;
class OrderAccess;
// Holder (or cage) for the C++ vtable of each kind of Klass.
// We want to tightly constrain the location of the C++ vtable in the overall layout.
class Klass_vtbl {
protected:
// The following virtual exists only to force creation of a C++ vtable,
// so that this class truly is the location of the vtable of all Klasses.
virtual void unused_initial_virtual() { }
public:
// The following virtual makes Klass_vtbl play a second role as a
// factory protocol for subclasses of Klass ("sub-Klasses").
// Here's how it works....
//
// This VM uses metaobjects as factories for their instances.
//
// In order to initialize the C++ vtable of a new instance, its
// metaobject is forced to use the C++ placed new operator to
// allocate the instance. In a typical C++-based system, each
// sub-class would have its own factory routine which
// directly uses the placed new operator on the desired class,
// and then calls the appropriate chain of C++ constructors.
//
// However, this system uses shared code to performs the first
// allocation and initialization steps for all sub-Klasses.
// (See base_create_klass() and base_create_array_klass().)
// This does not factor neatly into a hierarchy of C++ constructors.
// Each caller of these shared "base_create" routines knows
// exactly which sub-Klass it is creating, but the shared routine
// does not, even though it must perform the actual allocation.
//
// Therefore, the caller of the shared "base_create" must wrap
// the specific placed new call in a virtual function which
// performs the actual allocation and vtable set-up. That
// virtual function is here, Klass_vtbl::allocate_permanent.
//
// The arguments to Universe::allocate_permanent() are passed
// straight through the placed new operator, which in turn
// obtains them directly from this virtual call.
//
// This virtual is called on a temporary "example instance" of the
// sub-Klass being instantiated, a C++ auto variable. The "real"
// instance created by this virtual is on the VM heap, where it is
// equipped with a klassOopDesc header.
//
// It is merely an accident of implementation that we use "example
// instances", but that is why the virtual function which implements
// each sub-Klass factory happens to be defined by the same sub-Klass
// for which it creates instances.
//
// The vtbl_value() call (see below) is used to strip away the
// accidental Klass-ness from an "example instance" and present it as
// a factory. Think of each factory object as a mere container of the
// C++ vtable for the desired sub-Klass. Since C++ does not allow
// direct references to vtables, the factory must also be delegated
// the task of allocating the instance, but the essential point is
// that the factory knows how to initialize the C++ vtable with the
// right pointer value. All other common initializations are handled
// by the shared "base_create" subroutines.
//
virtual void* allocate_permanent(KlassHandle& klass, int size, TRAPS) const = 0;
void post_new_init_klass(KlassHandle& klass, klassOop obj, int size) const;
// Every subclass on which vtbl_value is called must include this macro.
// Delay the installation of the klassKlass pointer until after the
// the vtable for a new klass has been installed (after the call to new()).
#define DEFINE_ALLOCATE_PERMANENT(thisKlass) \
void* allocate_permanent(KlassHandle& klass_klass, int size, TRAPS) const { \
void* result = new(klass_klass, size, THREAD) thisKlass(); \
if (HAS_PENDING_EXCEPTION) return NULL; \
klassOop new_klass = ((Klass*) result)->as_klassOop(); \
OrderAccess::storestore(); \
post_new_init_klass(klass_klass, new_klass, size); \
return result; \
}
bool null_vtbl() { return *(intptr_t*)this == 0; }
protected:
void* operator new(size_t ignored, KlassHandle& klass, int size, TRAPS);
};
class Klass : public Klass_vtbl {
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 Klass_vtbl,
// 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;
public:
oop* oop_block_beg() const { return adr_secondary_super_cache(); }
oop* oop_block_end() const { return adr_next_sibling() + 1; }
protected:
//
// The oop block. All oop fields must be declared here and only oop fields
// may be declared here. In addition, the first and last fields in this block
// must remain first and last, unless oop_block_beg() and/or oop_block_end()
// are updated. Grouping the oop fields in a single block simplifies oop
// iteration.
//
// Cache of last observed secondary supertype
klassOop _secondary_super_cache;
// Array of all secondary supertypes
objArrayOop _secondary_supers;
// Ordered list of all primary supertypes
klassOop _primary_supers[_primary_super_limit];
// java/lang/Class instance mirroring this class
oop _java_mirror;
// Superclass
klassOop _super;
// First subclass (NULL if none); _subklass->next_sibling() is next one
klassOop _subklass;
// Sibling link (or NULL); links all subklasses of a klass
klassOop _next_sibling;
//
// End of the oop block.
//
jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
#ifndef PRODUCT
int _verify_count; // to avoid redundant verifies
#endif
juint _alloc_count; // allocation profiling support - update klass_size_in_bytes() if moved/deleted
// 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;
#ifdef TRACE_DEFINE_KLASS_TRACE_ID
TRACE_DEFINE_KLASS_TRACE_ID;
#endif
public:
// returns the enclosing klassOop
klassOop as_klassOop() const {
// see klassOop.hpp for layout.
return (klassOop) (((char*) this) - sizeof(klassOopDesc));
}
public:
// Allocation
const Klass_vtbl& vtbl_value() const { return *this; } // used only on "example instances"
static KlassHandle base_create_klass(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS);
static klassOop base_create_klass_oop(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS);
// super
klassOop super() const { return _super; }
void set_super(klassOop k) { oop_store_without_check((oop*) &_super, (oop) k); }
// initializes _super link, _primary_supers & _secondary_supers arrays
void initialize_supers(klassOop k, TRAPS);
void initialize_supers_impl1(klassOop k);
void initialize_supers_impl2(klassOop k);
// klass-specific helper for initializing _secondary_supers
virtual objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
// java_super is the Java-level super type as specified by Class.getSuperClass.
virtual klassOop 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; }
klassOop secondary_super_cache() const { return _secondary_super_cache; }
void set_secondary_super_cache(klassOop k) { oop_store_without_check((oop*) &_secondary_super_cache, (oop) k); }
objArrayOop secondary_supers() const { return _secondary_supers; }
void set_secondary_supers(objArrayOop k) { oop_store_without_check((oop*) &_secondary_supers, (oop) k); }
// Return the element of the _super chain of the given depth.
// If there is no such element, return either NULL or this.
klassOop primary_super_of_depth(juint i) const {
assert(i < primary_super_limit(), "oob");
klassOop super = _primary_supers[i];
assert(super == NULL || super->klass_part()->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(klassOop);
assert(d < primary_super_limit(), "oob");
assert(_primary_supers[d] == as_klassOop(), "proper init");
return d;
}
}
// java mirror
oop java_mirror() const { return _java_mirror; }
void set_java_mirror(oop m) { oop_store((oop*) &_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 remove_from_sibling_list(); // remove receiver from sibling list
protected: // internal accessors
klassOop subklass_oop() const { return _subklass; }
klassOop next_sibling_oop() const { return _next_sibling; }
void set_subklass(klassOop s);
void set_next_sibling(klassOop s);
oop* adr_super() const { return (oop*)&_super; }
oop* adr_primary_supers() const { return (oop*)&_primary_supers[0]; }
oop* adr_secondary_super_cache() const { return (oop*)&_secondary_super_cache; }
oop* adr_secondary_supers()const { return (oop*)&_secondary_supers; }
oop* adr_java_mirror() const { return (oop*)&_java_mirror; }
oop* adr_subklass() const { return (oop*)&_subklass; }
oop* adr_next_sibling() const { return (oop*)&_next_sibling; }
public:
// Allocation profiling support
juint alloc_count() const { return _alloc_count; }
void set_alloc_count(juint n) { _alloc_count = n; }
virtual juint alloc_size() const = 0;
virtual void set_alloc_size(juint n) = 0;
// Compiler support
static ByteSize super_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _super)); }
static ByteSize super_check_offset_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _super_check_offset)); }
static ByteSize primary_supers_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _primary_supers)); }
static ByteSize secondary_super_cache_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _secondary_super_cache)); }
static ByteSize secondary_supers_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _secondary_supers)); }
static ByteSize java_mirror_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _java_mirror)); }
static ByteSize modifier_flags_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _modifier_flags)); }
static ByteSize layout_helper_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(Klass, _layout_helper)); }
static ByteSize access_flags_offset() { return in_ByteSize(sizeof(klassOopDesc) + 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_javaArray(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, "sanity");
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; }
static int klass_size_in_bytes() { return offset_of(Klass, _alloc_count) + sizeof(juint); } // all "visible" fields
// subclass check
bool is_subclass_of(klassOop k) const;
// subtype check: true if is_subclass_of, or if k is interface and receiver implements it
bool is_subtype_of(klassOop k) const {
juint off = k->klass_part()->super_check_offset();
klassOop sup = *(klassOop*)( (address)as_klassOop() + 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(klassOop 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);
// Casting
static Klass* cast(klassOop k) {
assert(k->is_klass(), "cast to Klass");
return k->klass_part();
}
// 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 methodOop uncached_lookup_method(Symbol* name, Symbol* signature) const;
public:
methodOop lookup_method(Symbol* name, Symbol* signature) const {
return uncached_lookup_method(name, signature);
}
// array class with specific rank
klassOop array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
// array class with this klass as element type
klassOop 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.
klassOop array_klass_or_null(int rank);
klassOop array_klass_or_null();
virtual oop protection_domain() { return NULL; }
virtual oop class_loader() const { return NULL; }
protected:
virtual klassOop array_klass_impl(bool or_null, int rank, TRAPS);
virtual klassOop array_klass_impl(bool or_null, TRAPS);
public:
virtual void remove_unshareable_info();
virtual void shared_symbols_iterate(SymbolClosure* closure);
protected:
// computes the subtype relationship
virtual bool compute_is_subtype_of(klassOop 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;
// actual oop size of this klass in memory
virtual int klass_oop_size() const = 0;
// 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
public:
// type testing operations
virtual bool oop_is_instance_slow() const { return false; }
virtual bool oop_is_instanceMirror() const { return false; }
virtual bool oop_is_instanceRef() const { return false; }
virtual bool oop_is_array() const { return false; }
virtual bool oop_is_objArray_slow() const { return false; }
virtual bool oop_is_klass() const { return false; }
virtual bool oop_is_thread() const { return false; }
virtual bool oop_is_method() const { return false; }
virtual bool oop_is_constMethod() const { return false; }
virtual bool oop_is_methodData() const { return false; }
virtual bool oop_is_constantPool() const { return false; }
virtual bool oop_is_constantPoolCache() const { return false; }
virtual bool oop_is_typeArray_slow() const { return false; }
virtual bool oop_is_arrayKlass() const { return false; }
virtual bool oop_is_objArrayKlass() const { return false; }
virtual bool oop_is_typeArrayKlass() const { return false; }
virtual bool oop_is_compiledICHolder() const { return false; }
virtual bool oop_is_instanceKlass() const { return false; }
bool oop_is_javaArray_slow() const {
return oop_is_objArray_slow() || oop_is_typeArray_slow();
}
// Fast non-virtual versions, used by oop.inline.hpp and elsewhere:
#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_javaArray() const { return assert_same_query(
layout_helper_is_javaArray(layout_helper()),
oop_is_javaArray_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
// Unless overridden, oop is parsable if it has a klass pointer.
// Parsability of an object is object specific.
virtual bool oop_is_parsable(oop obj) const { return true; }
// Unless overridden, oop is safe for concurrent GC processing
// after its allocation is complete. The exception to
// this is the case where objects are changed after allocation.
// Class redefinition is one of the known exceptions. During
// class redefinition, an allocated class can changed in order
// order to create a merged class (the combiniation of the
// old class definition that has to be perserved and the new class
// definition which is being created.
virtual bool oop_is_conc_safe(oop obj) const { return true; }
// 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(sizeof(klassOopDesc) + 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; }
#ifdef TRACE_DEFINE_KLASS_METHODS
TRACE_DEFINE_KLASS_METHODS;
#endif
// garbage collection support
virtual void follow_weak_klass_links(
BoolObjectClosure* is_alive, OopClosure* keep_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, OopClosure* blk) = 0;
virtual int oop_oop_iterate_v(oop obj, OopClosure* blk) {
return oop_oop_iterate(obj, blk);
}
#ifndef SERIALGC
// In case we don't have a specialized backward scanner use forward
// iteration.
virtual int oop_oop_iterate_backwards_v(oop obj, OopClosure* blk) {
return oop_oop_iterate_v(obj, blk);
}
#endif // !SERIALGC
// 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, OopClosure* blk, MemRegion mr) = 0;
virtual int oop_oop_iterate_v_m(oop obj, OopClosure* 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)
#ifndef SERIALGC
#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 // !SERIALGC
virtual void array_klasses_do(void f(klassOop k)) {}
virtual void with_array_klasses_do(void f(klassOop 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);
friend class klassKlass;
public:
// jvm support
virtual jint compute_modifier_flags(TRAPS) const;
// JVMTI support
virtual jint jvmti_class_status() const;
// Printing
virtual void oop_print_value_on(oop obj, outputStream* st);
virtual void oop_print_on (oop obj, outputStream* st);
// Verification
virtual const char* internal_name() const = 0;
virtual void oop_verify_on(oop obj, outputStream* st);
virtual void oop_verify_old_oop(oop obj, oop* p, bool allow_dirty);
virtual void oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty);
// tells whether obj is partially constructed (gc during class loading)
virtual bool oop_partially_loaded(oop obj) const { return false; }
virtual void oop_set_partially_loaded(oop obj) {};
#ifndef PRODUCT
void verify_vtable_index(int index);
#endif
};
inline oop klassOopDesc::java_mirror() const { return klass_part()->java_mirror(); }
#endif // SHARE_VM_OOPS_KLASS_HPP