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#ifndef SHARE_VM_OOPS_CPCACHEOOP_HPP
#define SHARE_VM_OOPS_CPCACHEOOP_HPP
#include "interpreter/bytecodes.hpp"
#include "memory/allocation.hpp"
#include "oops/arrayOop.hpp"
// A ConstantPoolCacheEntry describes an individual entry of the constant
// pool cache. There's 2 principal kinds of entries: field entries for in-
// stance & static field access, and method entries for invokes. Some of
// the entry layout is shared and looks as follows:
//
// bit number |31 0|
// bit length |-8--|-8--|---16----|
// --------------------------------
// _indices [ b2 | b1 | index ] index = constant_pool_index (!= 0, normal entries only)
// _indices [ index | 00000 ] index = main_entry_index (secondary entries only)
// _f1 [ entry specific ] method, klass, or oop (MethodType or CallSite)
// _f2 [ entry specific ] vtable index or vfinal method
// _flags [tos|0|00|00|00|f|v|f2|unused|field_index] (for field entries)
// bit length [ 4 |1|1 |1 | 1|1|1| 1|---5--|----16-----]
// _flags [tos|M|vf|fv|ea|f|0|f2|unused|00000|psize] (for method entries)
// bit length [ 4 |1|1 |1 | 1|1|1| 1|---5--|--8--|--8--]
// --------------------------------
//
// with:
// index = original constant pool index
// b1 = bytecode 1
// b2 = bytecode 2
// psize = parameters size (method entries only)
// field_index = index into field information in holder instanceKlass
// The index max is 0xffff (max number of fields in constant pool)
// and is multiplied by (instanceKlass::next_offset) when accessing.
// t = TosState (see below)
// f = field is marked final (see below)
// f2 = virtual but final (method entries only: is_vfinal())
// v = field is volatile (see below)
// m = invokeinterface used for method in class Object (see below)
// h = RedefineClasses/Hotswap bit (see below)
//
// The flags after TosState have the following interpretation:
// bit 27: 0 for fields, 1 for methods
// f flag true if field is marked final
// v flag true if field is volatile (only for fields)
// f2 flag true if f2 contains an oop (e.g., virtual final method)
// fv flag true if invokeinterface used for method in class Object
//
// The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the
// following mapping to the TosState states:
//
// btos: 0
// ctos: 1
// stos: 2
// itos: 3
// ltos: 4
// ftos: 5
// dtos: 6
// atos: 7
// vtos: 8
//
// Entry specific: field entries:
// _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
// _f1 = field holder (as a java.lang.Class, not a klassOop)
// _f2 = field offset in bytes
// _flags = field type information, original FieldInfo index in field holder
// (field_index section)
//
// Entry specific: method entries:
// _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
// original constant pool index
// _f1 = methodOop for non-virtual calls, unused by virtual calls.
// for interface calls, which are essentially virtual but need a klass,
// contains klassOop for the corresponding interface.
// for invokedynamic, f1 contains a site-specific CallSite object (as an appendix)
// for invokehandle, f1 contains a site-specific MethodType object (as an appendix)
// (upcoming metadata changes will move the appendix to a separate array)
// unused by non-virtual. The is_vfinal flag indicates this is a
// method pointer for a final method, not an index.
// _flags = method type info (t section),
// virtual final bit (vfinal),
// parameter size (psize section)
//
// Note: invokevirtual & invokespecial bytecodes can share the same constant
// pool entry and thus the same constant pool cache entry. All invoke
// bytecodes but invokevirtual use only _f1 and the corresponding b1
// bytecode, while invokevirtual uses only _f2 and the corresponding
// b2 bytecode. The value of _flags is shared for both types of entries.
//
// The fields are volatile so that they are stored in the order written in the
// source code. The _indices field with the bytecode must be written last.
friend class VMStructs;
friend class constantPoolCacheKlass;
friend class constantPoolOopDesc; //resolve_constant_at_impl => set_f1
private:
#ifdef ASSERT
#endif
}
void set_f2_as_vfinal_method(methodOop f2) { assert(_f2 == 0 || _f2 == (intptr_t) f2, "illegal field change"); assert(is_vfinal(), "flags must be set"); _f2 = (intptr_t) f2; }
}
}
}
public:
// specific bit definitions for the flags field:
// (Note: the interpreter must use these definitions to access the CP cache.)
enum {
// high order bits are the TosState corresponding to field type or method return type
// misc. option bits; can be any bit position in [16..27]
// low order bits give field index (for FieldInfo) or method parameter size:
};
// specific bit definitions for the indices field:
enum {
// the secondary cp index overlaps with bytecodes 1 and 2:
};
// Initialization
void set_field( // sets entry to resolved field state
int orig_field_index, // the original field index in the field holder
int field_offset, // the field offset in words in the field holder
bool is_final, // the field is final
bool is_volatile // the field is volatile
);
void set_method( // sets entry to resolved method entry
int vtable_index // the vtable index if any, else negative
);
void set_interface_call(
int index // Method index into interface
);
void set_method_handle(
);
void set_dynamic_call(
);
// Common code for invokedynamic and MH invocations.
// The "appendix" is an optional call-site-specific parameter which is
// pushed by the JVM at the end of the argument list. This argument may
// be a MethodType for the MH.invokes and a CallSite for an invokedynamic
// instruction. However, its exact type and use depends on the Java upcall,
// which simply returns a compiled LambdaForm along with any reference
// that LambdaForm needs to complete the call. If the upcall returns a
// null appendix, the argument is not passed at all.
//
// The appendix is *not* represented in the signature of the symbolic
// reference for the call site, but (if present) it *is* represented in
// the methodOop bound to the site. This means that static and dynamic
// resolution logic needs to make slightly different assessments about the
// number and types of arguments.
void set_method_handle_common(
);
void set_parameter_size(int value);
// Which bytecode number (1 or 2) in the index field is valid for this bytecode?
// Returns -1 if neither is valid.
switch (code) {
default : break;
}
return -1;
}
switch (bytecode_number(code)) {
}
return false; // default: not resolved
}
// Accessors
return _indices; }
Bytecodes::Code bytecode_1() const { return Bytecodes::cast((primary_entry_indices() >> bytecode_1_shift)
& bytecode_1_mask); }
Bytecodes::Code bytecode_2() const { return Bytecodes::cast((primary_entry_indices() >> bytecode_2_shift)
& bytecode_2_mask); }
methodOop f1_as_method() const { oop f1 = _f1; assert(f1 == NULL || f1->is_method(), ""); return methodOop(f1); }
klassOop f1_as_klass() const { oop f1 = _f1; assert(f1 == NULL || f1->is_klass(), ""); return klassOop(f1); }
oop f1_as_klass_mirror() const { oop f1 = f1_as_instance(); return f1; } // i.e., return a java_mirror
oop f1_as_instance() const { oop f1 = _f1; assert(f1 == NULL || f1->is_instance() || f1->is_array(), ""); return f1; }
int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
// Code generation support
// GC Support
void follow_contents();
void adjust_pointers();
#ifndef SERIALGC
// Parallel Old
#endif // SERIALGC
void update_pointers();
// RedefineClasses() API support:
// If this constantPoolCacheEntry refers to old_method then update it
// to refer to 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 * trace_name_printed);
bool check_no_old_or_obsolete_entries();
bool is_interesting_method_entry(klassOop k);
// Debugging & Printing
static void verify_tos_state_shift() {
// When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
}
};
// A constant pool cache is a runtime data structure set aside to a constant pool. The cache
// holds interpreter runtime information for all field access and invoke bytecodes. The cache
// is created and initialized before a class is actively used (i.e., initialized), the indivi-
// dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
friend class VMStructs;
private:
int _length;
// Sizing
debug_only(friend class ClassVerifier;)
public:
private:
static int object_size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
// Helpers
ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
friend class constantPoolCacheKlass;
friend class ConstantPoolCacheEntry;
public:
// Initialization
// Secondary indexes.
// They must look completely different from normal indexes.
// The main reason is that byte swapping is sometimes done on normal indexes.
// Also, some of the CP accessors do different things for secondary indexes.
// Finally, it is helpful for debugging to tell the two apart.
static bool is_secondary_index(int i) { return (i < 0); }
// Accessors
void set_constant_pool(constantPoolOop pool) { oop_store_without_check((oop*)&_constant_pool, (oop)pool); }
// Fetches the entry at the given index.
// The entry may be either primary or secondary.
// In either case the index must not be encoded or byte-swapped in any way.
return base() + i;
}
// Fetches the secondary entry referred to by index.
// The index may be a secondary index, and must not be byte-swapped.
int raw_index = i;
if (is_secondary_index(i)) { // correct these on the fly
}
}
// Given a primary or secondary index, fetch the corresponding primary entry.
// Indirect through the secondary entry, if the index is encoded as a secondary index.
// The index must not be byte-swapped.
int primary_index = i;
if (is_secondary_index(i)) {
// run through an extra level of indirection:
}
return entry_at(primary_index);
}
return cpc_index;
}
if (e->is_secondary_entry()) {
return e2;
} else {
for (int i = length() - 1; i >= 0; i--) {
return e2;
}
}
fatal("no secondary entry found");
return NULL;
}
// Code generation
if (is_secondary_index(raw_index))
}
// RedefineClasses() API support:
// If any entry of this constantPoolCache 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.
int methods_length, bool * trace_name_printed);
bool check_no_old_or_obsolete_entries();
void dump_cache();
};
#endif // SHARE_VM_OOPS_CPCACHEOOP_HPP