JDK14/Java14源码在线阅读
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#ifndef SHARE_OOPS_CPCACHE_HPP
#define SHARE_OOPS_CPCACHE_HPP
#include "interpreter/bytecodes.hpp"
#include "memory/allocation.hpp"
#include "oops/array.hpp"
#include "oops/oopHandle.hpp"
#include "runtime/handles.hpp"
#include "utilities/align.hpp"
#include "utilities/constantTag.hpp"
#include "utilities/growableArray.hpp"
class PSPromotionManager;
// The ConstantPoolCache is not a cache! It is the resolution table that the
// interpreter uses to avoid going into the runtime and a way to access resolved
// values.
// 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
// _f1 [ entry specific ] metadata ptr (method or klass)
// _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr
// _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)
// bit length [ 4 |1| 1 |1|1|1|1|1|1 |1 |-3-|----16-----]
// _flags [tos|0|F=0|S|A|I|f|0|vf|indy_rf|000|00000|psize] (for method entries)
// bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--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.
// tos = TosState
// F = the entry is for a field (or F=0 for a method)
// A = call site has an appendix argument (loaded from resolved references)
// I = interface call is forced virtual (must use a vtable index or vfinal)
// f = field or method is final
// v = field is volatile
// vf = virtual but final (method entries only: is_vfinal())
// indy_rf = call site specifier method resolution failed
//
// 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 16 with the
// following mapping to the TosState states:
//
// btos: 0
// ztos: 1
// ctos: 2
// stos: 3
// itos: 4
// ltos: 5
// ftos: 6
// dtos: 7
// atos: 8
// vtos: 9
//
// 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 Klass*)
// _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 = Method* for non-virtual calls, unused by virtual calls.
// for interface calls, which are essentially virtual but need a klass,
// contains Klass* for the corresponding interface.
// for invokedynamic and invokehandle, f1 contains the adapter method which
// manages the actual call. The appendix is stored in the ConstantPool
// resolved_references array.
// (upcoming metadata changes will move the appendix to a separate array)
// _f2 = vtable/itable index (or final Method*) for virtual calls only,
// unused by non-virtual. The is_vfinal flag indicates this is a
// method pointer for a final method, not an index.
// _flags = has local signature (MHs and indy),
// 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.
class CallInfo;
class ConstantPoolCacheEntry {
friend class VMStructs;
friend class constantPoolCacheKlass;
friend class ConstantPool;
friend class InterpreterRuntime;
private:
volatile intx _indices; // constant pool index & rewrite bytecodes
Metadata* volatile _f1; // entry specific metadata field
volatile intx _f2; // entry specific int/metadata field
volatile intx _flags; // flags
void set_bytecode_1(Bytecodes::Code code);
void set_bytecode_2(Bytecodes::Code code);
void set_f1(Metadata* f1) {
Metadata* existing_f1 = _f1; // read once
assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
_f1 = f1;
}
void release_set_f1(Metadata* f1);
void set_f2(intx f2) {
intx existing_f2 = _f2; // read once
assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
_f2 = f2;
}
void set_f2_as_vfinal_method(Method* f2) {
assert(is_vfinal(), "flags must be set");
set_f2((intx)f2);
}
int make_flags(TosState state, int option_bits, int field_index_or_method_params);
void set_flags(intx flags) { _flags = flags; }
void set_field_flags(TosState field_type, int option_bits, int field_index) {
assert((field_index & field_index_mask) == field_index, "field_index in range");
set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
}
void set_method_flags(TosState return_type, int option_bits, int method_params) {
assert((method_params & parameter_size_mask) == method_params, "method_params in range");
set_flags(make_flags(return_type, option_bits, method_params));
}
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
tos_state_bits = 4,
tos_state_mask = right_n_bits(tos_state_bits),
tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below
// misc. option bits; can be any bit position in [16..27]
is_field_entry_shift = 26, // (F) is it a field or a method?
has_local_signature_shift = 25, // (S) does the call site have a per-site signature (sig-poly methods)?
has_appendix_shift = 24, // (A) does the call site have an appendix argument?
is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode?
is_final_shift = 22, // (f) is the field or method final?
is_volatile_shift = 21, // (v) is the field volatile?
is_vfinal_shift = 20, // (vf) did the call resolve to a final method?
indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ?
// low order bits give field index (for FieldInfo) or method parameter size:
field_index_bits = 16,
field_index_mask = right_n_bits(field_index_bits),
parameter_size_bits = 8, // subset of field_index_mask, range is 0..255
parameter_size_mask = right_n_bits(parameter_size_bits),
option_bits_mask = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask))
};
// specific bit definitions for the indices field:
enum {
cp_index_bits = 2*BitsPerByte,
cp_index_mask = right_n_bits(cp_index_bits),
bytecode_1_shift = cp_index_bits,
bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF
bytecode_2_shift = cp_index_bits + BitsPerByte,
bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF
};
// Initialization
void initialize_entry(int original_index); // initialize primary entry
void initialize_resolved_reference_index(int ref_index) {
assert(_f2 == 0, "set once"); // note: ref_index might be zero also
_f2 = ref_index;
}
void set_field( // sets entry to resolved field state
Bytecodes::Code get_code, // the bytecode used for reading the field
Bytecodes::Code put_code, // the bytecode used for writing the field
Klass* field_holder, // the object/klass holding the field
int orig_field_index, // the original field index in the field holder
int field_offset, // the field offset in words in the field holder
TosState field_type, // the (machine) field type
bool is_final, // the field is final
bool is_volatile, // the field is volatile
Klass* root_klass // needed by the GC to dirty the klass
);
private:
void set_direct_or_vtable_call(
Bytecodes::Code invoke_code, // the bytecode used for invoking the method
const methodHandle& method, // the method/prototype if any (NULL, otherwise)
int vtable_index, // the vtable index if any, else negative
bool sender_is_interface
);
public:
void set_direct_call( // sets entry to exact concrete method entry
Bytecodes::Code invoke_code, // the bytecode used for invoking the method
const methodHandle& method, // the method to call
bool sender_is_interface
);
void set_vtable_call( // sets entry to vtable index
Bytecodes::Code invoke_code, // the bytecode used for invoking the method
const methodHandle& method, // resolved method which declares the vtable index
int vtable_index // the vtable index
);
void set_itable_call(
Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
Klass* referenced_klass, // the referenced klass in the InterfaceMethodref
const methodHandle& method, // the resolved interface method
int itable_index // index into itable for the method
);
void set_method_handle(
const constantPoolHandle& cpool, // holding constant pool (required for locking)
const CallInfo &call_info // Call link information
);
void set_dynamic_call(
const constantPoolHandle& cpool, // holding constant pool (required for locking)
const CallInfo &call_info // Call link information
);
// 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 Method* 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(
const constantPoolHandle& cpool, // holding constant pool (required for locking)
Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic
const CallInfo &call_info // Call link information
);
// Return TRUE if resolution failed and this thread got to record the failure
// status. Return FALSE if another thread succeeded or failed in resolving
// the method and recorded the success or failure before this thread had a
// chance to record its failure.
bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index,
int index, constantTag tag, TRAPS);
// invokedynamic and invokehandle call sites have an "appendix" item in the
// resolved references array.
Method* method_if_resolved(const constantPoolHandle& cpool);
oop appendix_if_resolved(const constantPoolHandle& cpool);
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.
static int bytecode_number(Bytecodes::Code code) {
switch (code) {
case Bytecodes::_getstatic : // fall through
case Bytecodes::_getfield : // fall through
case Bytecodes::_invokespecial : // fall through
case Bytecodes::_invokestatic : // fall through
case Bytecodes::_invokehandle : // fall through
case Bytecodes::_invokedynamic : // fall through
case Bytecodes::_invokeinterface : return 1;
case Bytecodes::_putstatic : // fall through
case Bytecodes::_putfield : // fall through
case Bytecodes::_invokevirtual : return 2;
default : break;
}
return -1;
}
// Has this bytecode been resolved? Only valid for invokes and get/put field/static.
bool is_resolved(Bytecodes::Code code) const;
// Accessors
int indices() const { return _indices; }
int indices_ord() const;
int constant_pool_index() const { return (indices() & cp_index_mask); }
Bytecodes::Code bytecode_1() const;
Bytecodes::Code bytecode_2() const;
Metadata* f1_ord() const;
Method* f1_as_method() const;
Klass* f1_as_klass() const;
// Use the accessor f1() to acquire _f1's value. This is needed for
// example in BytecodeInterpreter::run(), where is_f1_null() is
// called to check if an invokedynamic call is resolved. This load
// of _f1 must be ordered with the loads performed by
// cache->main_entry_index().
bool is_f1_null() const; // classifies a CPC entry as unbound
int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
Method* f2_as_interface_method() const;
intx flags_ord() const;
int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); }
int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; }
bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; }
bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; }
bool indy_resolution_failed() const;
bool has_appendix() const;
bool has_local_signature() const;
bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
bool is_long() const { return flag_state() == ltos; }
bool is_double() const { return flag_state() == dtos; }
TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
void set_indy_resolution_failed();
// Code generation support
static WordSize size() {
return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize);
}
static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
#if INCLUDE_JVMTI
// 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.
void adjust_method_entry(Method* old_method, Method* new_method,
bool* trace_name_printed);
bool check_no_old_or_obsolete_entries();
Method* get_interesting_method_entry();
#endif // INCLUDE_JVMTI
// Debugging & Printing
void print (outputStream* st, int index) const;
void verify(outputStream* st) const;
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:
assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
}
void verify_just_initialized(bool f2_used);
void reinitialize(bool f2_used);
};
// 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.*).
class ConstantPoolCache: public MetaspaceObj {
friend class VMStructs;
friend class MetadataFactory;
private:
// If you add a new field that points to any metaspace object, you
// must add this field to ConstantPoolCache::metaspace_pointers_do().
int _length;
ConstantPool* _constant_pool; // the corresponding constant pool
// The following fields need to be modified at runtime, so they cannot be
// stored in the ConstantPool, which is read-only.
// Array of resolved objects from the constant pool and map from resolved
// object index to original constant pool index
OopHandle _resolved_references;
Array<u2>* _reference_map;
// The narrowOop pointer to the archived resolved_references. Set at CDS dump
// time when caching java heap object is supported.
CDS_JAVA_HEAP_ONLY(narrowOop _archived_references;)
// Sizing
debug_only(friend class ClassVerifier;)
// Constructor
ConstantPoolCache(int length,
const intStack& inverse_index_map,
const intStack& invokedynamic_inverse_index_map,
const intStack& invokedynamic_references_map);
// Initialization
void initialize(const intArray& inverse_index_map,
const intArray& invokedynamic_inverse_index_map,
const intArray& invokedynamic_references_map);
public:
static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
const intStack& cp_cache_map,
const intStack& invokedynamic_cp_cache_map,
const intStack& invokedynamic_references_map, TRAPS);
int length() const { return _length; }
void metaspace_pointers_do(MetaspaceClosure* it);
MetaspaceObj::Type type() const { return ConstantPoolCacheType; }
oop archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL);
void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN;
inline oop resolved_references();
void set_resolved_references(OopHandle s) { _resolved_references = s; }
Array<u2>* reference_map() const { return _reference_map; }
void set_reference_map(Array<u2>* o) { _reference_map = o; }
// Assembly code support
static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); }
// CDS support
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