8232006: Remove dead code from klassVtable
Reviewed-by: coleenp, jiangli, lfoltan
/*
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#ifndef SHARE_OOPS_KLASSVTABLE_HPP
#define SHARE_OOPS_KLASSVTABLE_HPP
#include "oops/oopsHierarchy.hpp"
#include "runtime/handles.hpp"
#include "utilities/growableArray.hpp"
// A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass
// and ArrayKlass. klassVtable objects are used just as convenient transient accessors to the vtable,
// not to actually hold the vtable data.
// Note: the klassVtable should not be accessed before the class has been verified
// (until that point, the vtable is uninitialized).
// Currently a klassVtable contains a direct reference to the vtable data, and is therefore
// not preserved across GCs.
class vtableEntry;
class klassVtable {
Klass* _klass; // my klass
int _tableOffset; // offset of start of vtable data within klass
int _length; // length of vtable (number of entries)
#ifndef PRODUCT
int _verify_count; // to make verify faster
#endif
public:
klassVtable(Klass* klass, void* base, int length) : _klass(klass) {
_tableOffset = (address)base - (address)klass; _length = length;
}
// accessors
vtableEntry* table() const { return (vtableEntry*)(address(_klass) + _tableOffset); }
Klass* klass() const { return _klass; }
int length() const { return _length; }
inline Method* method_at(int i) const;
inline Method* unchecked_method_at(int i) const;
// searching; all methods return -1 if not found
int index_of_miranda(Symbol* name, Symbol* signature);
void initialize_vtable(bool checkconstraints, TRAPS); // initialize vtable of a new klass
// computes vtable length (in words) and the number of miranda methods
static void compute_vtable_size_and_num_mirandas(int* vtable_length,
int* num_new_mirandas,
GrowableArray<Method*>* all_mirandas,
const Klass* super,
Array<Method*>* methods,
AccessFlags class_flags,
u2 major_version,
Handle classloader,
Symbol* classname,
Array<InstanceKlass*>* local_interfaces,
TRAPS);
#if INCLUDE_JVMTI
// RedefineClasses() API support:
// If any entry of this vtable points to any of old_methods,
// replace it with the corresponding new_method.
// trace_name_printed is set to true if the current call has
// printed the klass name so that other routines in the adjust_*
// group don't print the klass name.
bool adjust_default_method(int vtable_index, Method* old_method, Method* new_method);
void adjust_method_entries(bool* trace_name_printed);
bool check_no_old_or_obsolete_entries();
void dump_vtable();
#endif // INCLUDE_JVMTI
// Debugging code
void print() PRODUCT_RETURN;
void verify(outputStream* st, bool force = false);
static void print_statistics() PRODUCT_RETURN;
protected:
friend class vtableEntry;
public:
// Transitive overridng rules for class files < JDK1_7 use the older JVMS rules.
// Overriding is determined as we create the vtable, so we use the class file version
// of the class whose vtable we are calculating.
enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;
private:
void copy_vtable_to(vtableEntry* start);
int initialize_from_super(Klass* super);
void put_method_at(Method* m, int index);
static bool needs_new_vtable_entry(const methodHandle& m,
const Klass* super,
Handle classloader,
Symbol* classname,
AccessFlags access_flags,
u2 major_version,
TRAPS);
bool update_inherited_vtable(InstanceKlass* klass, const methodHandle& target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);
InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, const methodHandle& target_method, int vtable_index,
Handle target_loader, Symbol* target_classname, Thread* THREAD);
// support for miranda methods
bool is_miranda_entry_at(int i);
int fill_in_mirandas(int initialized, TRAPS);
static bool is_miranda(Method* m, Array<Method*>* class_methods,
Array<Method*>* default_methods, const Klass* super,
bool is_interface);
static void add_new_mirandas_to_lists(
GrowableArray<Method*>* new_mirandas,
GrowableArray<Method*>* all_mirandas,
Array<Method*>* current_interface_methods,
Array<Method*>* class_methods,
Array<Method*>* default_methods,
const Klass* super,
bool is_interface);
static void get_mirandas(
GrowableArray<Method*>* new_mirandas,
GrowableArray<Method*>* all_mirandas,
const Klass* super,
Array<Method*>* class_methods,
Array<Method*>* default_methods,
Array<InstanceKlass*>* local_interfaces,
bool is_interface);
void verify_against(outputStream* st, klassVtable* vt, int index);
inline InstanceKlass* ik() const;
// When loading a class from CDS archive at run time, and no class redefintion
// has happened, it is expected that the class's itable/vtables are
// laid out exactly the same way as they had been during dump time.
// Therefore, in klassVtable::initialize_[iv]table, we do not layout the
// tables again. Instead, we only rerun the process to create/check
// the class loader constraints. In non-product builds, we add asserts to
// guarantee that the table's layout would be the same as at dump time.
//
// If JVMTI redefines any class, the read-only shared memory are remapped
// as read-write. A shared class' vtable/itable are re-initialized and
// might have different layout due to class redefinition of the shared class
// or its super types.
bool is_preinitialized_vtable();
};
// private helper class for klassVtable
// description of entry points:
// destination is interpreted:
// from_compiled_code_entry_point -> c2iadapter
// from_interpreter_entry_point -> interpreter entry point
// destination is compiled:
// from_compiled_code_entry_point -> nmethod entry point
// from_interpreter_entry_point -> i2cadapter
class vtableEntry {
friend class VMStructs;
friend class JVMCIVMStructs;
public:
// size in words
static int size() { return sizeof(vtableEntry) / wordSize; }
static int size_in_bytes() { return sizeof(vtableEntry); }
static int method_offset_in_bytes() { return offset_of(vtableEntry, _method); }
Method* method() const { return _method; }
Method** method_addr() { return &_method; }
private:
Method* _method;
void set(Method* method) { assert(method != NULL, "use clear"); _method = method; }
void clear() { _method = NULL; }
void print() PRODUCT_RETURN;
void verify(klassVtable* vt, outputStream* st);
friend class klassVtable;
};
inline Method* klassVtable::method_at(int i) const {
assert(i >= 0 && i < _length, "index out of bounds");
assert(table()[i].method() != NULL, "should not be null");
assert(((Metadata*)table()[i].method())->is_method(), "should be method");
return table()[i].method();
}
inline Method* klassVtable::unchecked_method_at(int i) const {
assert(i >= 0 && i < _length, "index out of bounds");
return table()[i].method();
}
// --------------------------------------------------------------------------------
class klassItable;
class itableMethodEntry;
class itableOffsetEntry {
private:
InstanceKlass* _interface;
int _offset;
public:
InstanceKlass* interface_klass() const { return _interface; }
InstanceKlass**interface_klass_addr() { return &_interface; }
int offset() const { return _offset; }
static itableMethodEntry* method_entry(Klass* k, int offset) { return (itableMethodEntry*)(((address)k) + offset); }
itableMethodEntry* first_method_entry(Klass* k) { return method_entry(k, _offset); }
void initialize(InstanceKlass* interf, int offset) { _interface = interf; _offset = offset; }
// Static size and offset accessors
static int size() { return sizeof(itableOffsetEntry) / wordSize; } // size in words
static int interface_offset_in_bytes() { return offset_of(itableOffsetEntry, _interface); }
static int offset_offset_in_bytes() { return offset_of(itableOffsetEntry, _offset); }
friend class klassItable;
};
class itableMethodEntry {
private:
Method* _method;
public:
Method* method() const { return _method; }
Method**method_addr() { return &_method; }
void clear() { _method = NULL; }
void initialize(Method* method);
// Static size and offset accessors
static int size() { return sizeof(itableMethodEntry) / wordSize; } // size in words
static int method_offset_in_bytes() { return offset_of(itableMethodEntry, _method); }
friend class klassItable;
};
//
// Format of an itable
//
// ---- offset table ---
// Klass* of interface 1 \
// offset to vtable from start of oop / offset table entry
// ...
// Klass* of interface n \
// offset to vtable from start of oop / offset table entry
// --- vtable for interface 1 ---
// Method* \
// compiler entry point / method table entry
// ...
// Method* \
// compiler entry point / method table entry
// -- vtable for interface 2 ---
// ...
//
class klassItable {
private:
InstanceKlass* _klass; // my klass
int _table_offset; // offset of start of itable data within klass (in words)
int _size_offset_table; // size of offset table (in itableOffset entries)
int _size_method_table; // size of methodtable (in itableMethodEntry entries)
void initialize_itable_for_interface(int method_table_offset, InstanceKlass* interf_h, bool checkconstraints, TRAPS);
public:
klassItable(InstanceKlass* klass);
itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds");
return &((itableOffsetEntry*)vtable_start())[i]; }
itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds");
return &((itableMethodEntry*)method_start())[i]; }
int size_offset_table() { return _size_offset_table; }
// Initialization
void initialize_itable(bool checkconstraints, TRAPS);
#if INCLUDE_JVMTI
// RedefineClasses() API support:
// if any entry of this itable points to any of old_methods,
// replace it with the corresponding new_method.
// trace_name_printed is set to true if the current call has
// printed the klass name so that other routines in the adjust_*
// group don't print the klass name.
void adjust_method_entries(bool* trace_name_printed);
bool check_no_old_or_obsolete_entries();
void dump_itable();
#endif // INCLUDE_JVMTI
// Setup of itable
static int assign_itable_indices_for_interface(InstanceKlass* klass, TRAPS);
static int method_count_for_interface(InstanceKlass* klass);
static int compute_itable_size(Array<InstanceKlass*>* transitive_interfaces);
static void setup_itable_offset_table(InstanceKlass* klass);
// Debugging/Statistics
static void print_statistics() PRODUCT_RETURN;
private:
intptr_t* vtable_start() const { return ((intptr_t*)_klass) + _table_offset; }
intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }
// Helper methods
static int calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }
// Statistics
NOT_PRODUCT(static int _total_classes;) // Total no. of classes with itables
NOT_PRODUCT(static long _total_size;) // Total no. of bytes used for itables
static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })
};
#endif // SHARE_OOPS_KLASSVTABLE_HPP