6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
/*
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#ifndef SHARE_VM_OOPS_ARRAYKLASS_HPP
#define SHARE_VM_OOPS_ARRAYKLASS_HPP
#include "memory/universe.hpp"
#include "oops/klass.hpp"
class klassVtable;
// arrayKlass is the abstract baseclass for all array classes
class arrayKlass: public Klass {
friend class VMStructs;
private:
int _dimension; // This is n'th-dimensional array.
Klass* volatile _higher_dimension; // Refers the (n+1)'th-dimensional array (if present).
Klass* volatile _lower_dimension; // Refers the (n-1)'th-dimensional array (if present).
int _vtable_len; // size of vtable for this klass
juint _alloc_size; // allocation profiling support
oop _component_mirror; // component type, as a java/lang/Class
protected:
// Constructors
// The constructor with the Symbol argument does the real array
// initialization, the other is a dummy
arrayKlass(Symbol* name);
arrayKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for cds"); }
public:
// Testing operation
bool oop_is_array_slow() const { return true; }
// Instance variables
int dimension() const { return _dimension; }
void set_dimension(int dimension) { _dimension = dimension; }
Klass* higher_dimension() const { return _higher_dimension; }
void set_higher_dimension(Klass* k) { _higher_dimension = k; }
Klass** adr_higher_dimension() { return (Klass**)&this->_higher_dimension;}
Klass* lower_dimension() const { return _lower_dimension; }
void set_lower_dimension(Klass* k) { _lower_dimension = k; }
Klass** adr_lower_dimension() { return (Klass**)&this->_lower_dimension;}
// Allocation profiling support
juint alloc_size() const { return _alloc_size; }
void set_alloc_size(juint n) { _alloc_size = n; }
// offset of first element, including any padding for the sake of alignment
int array_header_in_bytes() const { return layout_helper_header_size(layout_helper()); }
int log2_element_size() const { return layout_helper_log2_element_size(layout_helper()); }
// type of elements (T_OBJECT for both oop arrays and array-arrays)
BasicType element_type() const { return layout_helper_element_type(layout_helper()); }
oop component_mirror() const { return _component_mirror; }
void set_component_mirror(oop m) { klass_oop_store(&_component_mirror, m); }
oop* adr_component_mirror() { return (oop*)&this->_component_mirror;}
// Compiler/Interpreter offset
static ByteSize component_mirror_offset() { return in_ByteSize(offset_of(arrayKlass, _component_mirror)); }
virtual Klass* java_super() const;//{ return SystemDictionary::Object_klass(); }
// Allocation
// Sizes points to the first dimension of the array, subsequent dimensions
// are always in higher memory. The callers of these set that up.
virtual oop multi_allocate(int rank, jint* sizes, TRAPS);
objArrayOop allocate_arrayArray(int n, int length, TRAPS);
// Lookup operations
Method* uncached_lookup_method(Symbol* name, Symbol* signature) const;
// Casting from Klass*
static arrayKlass* cast(Klass* k) {
assert(k->oop_is_array(), "cast to arrayKlass");
return (arrayKlass*) k;
}
GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots);
bool compute_is_subtype_of(Klass* k);
// Sizing
static int header_size() { return sizeof(arrayKlass)/HeapWordSize; }
static int static_size(int header_size);
// Java vtable
klassVtable* vtable() const; // return new klassVtable
int vtable_length() const { return _vtable_len; }
static int base_vtable_length() { return Universe::base_vtable_size(); }
void set_vtable_length(int len) { assert(len == base_vtable_length(), "bad length"); _vtable_len = len; }
protected:
inline intptr_t* start_of_vtable() const;
public:
// Iterators
void array_klasses_do(void f(Klass* k));
void array_klasses_do(void f(Klass* k, TRAPS), TRAPS);
void with_array_klasses_do(void f(Klass* k));
// GC support
virtual void oops_do(OopClosure* cl);
// Return a handle.
static void complete_create_array_klass(arrayKlass* k, KlassHandle super_klass, TRAPS);
// jvm support
jint compute_modifier_flags(TRAPS) const;
// JVMTI support
jint jvmti_class_status() const;
// CDS support - remove and restore oops from metadata. Oops are not shared.
virtual void remove_unshareable_info();
virtual void restore_unshareable_info(TRAPS);
// Printing
void print_on(outputStream* st) const;
void print_value_on(outputStream* st) const;
void oop_print_on(oop obj, outputStream* st);
// Verification
void verify_on(outputStream* st);
void oop_verify_on(oop obj, outputStream* st);
};
#endif // SHARE_VM_OOPS_ARRAYKLASS_HPP