7011386: race in objArrayKlass::array_klass_impl
Summary: Move _lower_dimension field initialization before _higher_dimension and add storestore barrier.
Reviewed-by: dholmes, iveresov, never
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#ifndef SHARE_VM_OOPS_ARRAYKLASS_HPP
#define SHARE_VM_OOPS_ARRAYKLASS_HPP
#include "memory/universe.hpp"
#include "oops/klass.hpp"
#include "oops/klassOop.hpp"
#include "oops/klassVtable.hpp"
// 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.
volatile klassOop _higher_dimension; // Refers the (n+1)'th-dimensional array (if present).
volatile klassOop _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
public:
// Testing operation
bool oop_is_array() const { return true; }
// Instance variables
int dimension() const { return _dimension; }
void set_dimension(int dimension) { _dimension = dimension; }
klassOop higher_dimension() const { return _higher_dimension; }
void set_higher_dimension(klassOop k) { oop_store_without_check((oop*) &_higher_dimension, (oop) k); }
oop* adr_higher_dimension() { return (oop*)&this->_higher_dimension;}
klassOop lower_dimension() const { return _lower_dimension; }
void set_lower_dimension(klassOop k) { oop_store_without_check((oop*) &_lower_dimension, (oop) k); }
oop* adr_lower_dimension() { return (oop*)&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) { oop_store((oop*) &_component_mirror, m); }
oop* adr_component_mirror() { return (oop*)&this->_component_mirror;}
// Compiler/Interpreter offset
static ByteSize component_mirror_offset() { return byte_offset_of(arrayKlass, _component_mirror); }
virtual klassOop 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
methodOop uncached_lookup_method(symbolOop name, symbolOop signature) const;
// Casting from klassOop
static arrayKlass* cast(klassOop k) {
Klass* kp = k->klass_part();
assert(kp->null_vtbl() || kp->oop_is_array(), "cast to arrayKlass");
return (arrayKlass*) kp;
}
objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
bool compute_is_subtype_of(klassOop k);
// Sizing
static int header_size() { return oopDesc::header_size() + sizeof(arrayKlass)/HeapWordSize; }
int object_size(int header_size) const;
bool object_is_parsable() const { return _vtable_len > 0; }
// 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(klassOop k));
void with_array_klasses_do(void f(klassOop k));
// Shared creation method
static arrayKlassHandle base_create_array_klass(
const Klass_vtbl& vtbl,
int header_size, KlassHandle klass,
TRAPS);
// Return a handle.
static void complete_create_array_klass(arrayKlassHandle k, KlassHandle super_klass, TRAPS);
// jvm support
jint compute_modifier_flags(TRAPS) const;
// JVMTI support
jint jvmti_class_status() const;
// Printing
void oop_print_on(oop obj, outputStream* st);
// Verification
void oop_verify_on(oop obj, outputStream* st);
};
#endif // SHARE_VM_OOPS_ARRAYKLASS_HPP