/*
* Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "gc_implementation/shared/markSweep.inline.hpp"
#include "interpreter/interpreter.hpp"
#include "interpreter/rewriter.hpp"
#include "memory/universe.inline.hpp"
#include "oops/cpCache.hpp"
#include "oops/objArrayOop.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvmtiRedefineClassesTrace.hpp"
#include "prims/methodHandles.hpp"
#include "runtime/handles.inline.hpp"
#ifndef SERIALGC
# include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
#endif
// Implememtation of ConstantPoolCacheEntry
void ConstantPoolCacheEntry::initialize_entry(int index) {
assert(0 < index && index < 0x10000, "sanity check");
_indices = index;
assert(constant_pool_index() == index, "");
}
int ConstantPoolCacheEntry::make_flags(TosState state,
int option_bits,
int field_index_or_method_params) {
assert(state < number_of_states, "Invalid state in make_flags");
int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
// Preserve existing flag bit values
// The low bits are a field offset, or else the method parameter size.
#ifdef ASSERT
TosState old_state = flag_state();
assert(old_state == (TosState)0 || old_state == state,
"inconsistent cpCache flags state");
#endif
return (_flags | f) ;
}
void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
#ifdef ASSERT
// Read once.
volatile Bytecodes::Code c = bytecode_1();
assert(c == 0 || c == code || code == 0, "update must be consistent");
#endif
// Need to flush pending stores here before bytecode is written.
OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));
}
void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
#ifdef ASSERT
// Read once.
volatile Bytecodes::Code c = bytecode_2();
assert(c == 0 || c == code || code == 0, "update must be consistent");
#endif
// Need to flush pending stores here before bytecode is written.
OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));
}
// Sets f1, ordering with previous writes.
void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
assert(f1 != NULL, "");
OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);
}
// Sets flags, but only if the value was previously zero.
bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
return (result == 0);
}
// Note that concurrent update of both bytecodes can leave one of them
// reset to zero. This is harmless; the interpreter will simply re-resolve
// the damaged entry. More seriously, the memory synchronization is needed
// to flush other fields (f1, f2) completely to memory before the bytecodes
// are updated, lest other processors see a non-zero bytecode but zero f1/f2.
void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
Bytecodes::Code put_code,
KlassHandle field_holder,
int field_index,
int field_offset,
TosState field_type,
bool is_final,
bool is_volatile,
Klass* root_klass) {
set_f1(field_holder());
set_f2(field_offset);
assert((field_index & field_index_mask) == field_index,
"field index does not fit in low flag bits");
set_field_flags(field_type,
((is_volatile ? 1 : 0) << is_volatile_shift) |
((is_final ? 1 : 0) << is_final_shift),
field_index);
set_bytecode_1(get_code);
set_bytecode_2(put_code);
NOT_PRODUCT(verify(tty));
}
void ConstantPoolCacheEntry::set_parameter_size(int value) {
// This routine is called only in corner cases where the CPCE is not yet initialized.
// See AbstractInterpreter::deopt_continue_after_entry.
assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
// Setting the parameter size by itself is only safe if the
// current value of _flags is 0, otherwise another thread may have
// updated it and we don't want to overwrite that value. Don't
// bother trying to update it once it's nonzero but always make
// sure that the final parameter size agrees with what was passed.
if (_flags == 0) {
Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
}
guarantee(parameter_size() == value,
err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
}
void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
methodHandle method,
int vtable_index) {
assert(method->interpreter_entry() != NULL, "should have been set at this point");
assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache");
int byte_no = -1;
bool change_to_virtual = false;
switch (invoke_code) {
case Bytecodes::_invokeinterface:
// We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
// instruction somehow links to a non-interface method (in Object).
// In that case, the method has no itable index and must be invoked as a virtual.
// Set a flag to keep track of this corner case.
change_to_virtual = true;
// ...and fall through as if we were handling invokevirtual:
case Bytecodes::_invokevirtual:
{
if (method->can_be_statically_bound()) {
// set_f2_as_vfinal_method checks if is_vfinal flag is true.
set_method_flags(as_TosState(method->result_type()),
( 1 << is_vfinal_shift) |
((method->is_final_method() ? 1 : 0) << is_final_shift) |
((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
method()->size_of_parameters());
set_f2_as_vfinal_method(method());
} else {
assert(vtable_index >= 0, "valid index");
assert(!method->is_final_method(), "sanity");
set_method_flags(as_TosState(method->result_type()),
((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
method()->size_of_parameters());
set_f2(vtable_index);
}
byte_no = 2;
break;
}
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
// Note: Read and preserve the value of the is_vfinal flag on any
// invokevirtual bytecode shared with this constant pool cache entry.
// It is cheap and safe to consult is_vfinal() at all times.
// Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
set_method_flags(as_TosState(method->result_type()),
((is_vfinal() ? 1 : 0) << is_vfinal_shift) |
((method->is_final_method() ? 1 : 0) << is_final_shift),
method()->size_of_parameters());
set_f1(method());
byte_no = 1;
break;
default:
ShouldNotReachHere();
break;
}
// Note: byte_no also appears in TemplateTable::resolve.
if (byte_no == 1) {
assert(invoke_code != Bytecodes::_invokevirtual &&
invoke_code != Bytecodes::_invokeinterface, "");
set_bytecode_1(invoke_code);
} else if (byte_no == 2) {
if (change_to_virtual) {
assert(invoke_code == Bytecodes::_invokeinterface, "");
// NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
//
// Workaround for the case where we encounter an invokeinterface, but we
// should really have an _invokevirtual since the resolved method is a
// virtual method in java.lang.Object. This is a corner case in the spec
// but is presumably legal. javac does not generate this code.
//
// We set bytecode_1() to _invokeinterface, because that is the
// bytecode # used by the interpreter to see if it is resolved.
// We set bytecode_2() to _invokevirtual.
// See also interpreterRuntime.cpp. (8/25/2000)
// Only set resolved for the invokeinterface case if method is public.
// Otherwise, the method needs to be reresolved with caller for each
// interface call.
if (method->is_public()) set_bytecode_1(invoke_code);
} else {
assert(invoke_code == Bytecodes::_invokevirtual, "");
}
// set up for invokevirtual, even if linking for invokeinterface also:
set_bytecode_2(Bytecodes::_invokevirtual);
} else {
ShouldNotReachHere();
}
NOT_PRODUCT(verify(tty));
}
void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
Klass* interf = method->method_holder();
assert(InstanceKlass::cast(interf)->is_interface(), "must be an interface");
assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
set_f1(interf);
set_f2(index);
set_method_flags(as_TosState(method->result_type()),
0, // no option bits
method()->size_of_parameters());
set_bytecode_1(Bytecodes::_invokeinterface);
}
void ConstantPoolCacheEntry::set_method_handle(constantPoolHandle cpool,
methodHandle adapter,
Handle appendix, Handle method_type,
objArrayHandle resolved_references) {
set_method_handle_common(cpool, Bytecodes::_invokehandle, adapter, appendix, method_type, resolved_references);
}
void ConstantPoolCacheEntry::set_dynamic_call(constantPoolHandle cpool,
methodHandle adapter,
Handle appendix, Handle method_type,
objArrayHandle resolved_references) {
set_method_handle_common(cpool, Bytecodes::_invokedynamic, adapter, appendix, method_type, resolved_references);
}
void ConstantPoolCacheEntry::set_method_handle_common(constantPoolHandle cpool,
Bytecodes::Code invoke_code,
methodHandle adapter,
Handle appendix, Handle method_type,
objArrayHandle resolved_references) {
// NOTE: This CPCE can be the subject of data races.
// There are three words to update: flags, refs[f2], f1 (in that order).
// Writers must store all other values before f1.
// Readers must test f1 first for non-null before reading other fields.
// Competing writers must acquire exclusive access via a lock.
// A losing writer waits on the lock until the winner writes f1 and leaves
// the lock, so that when the losing writer returns, he can use the linked
// cache entry.
MonitorLockerEx ml(cpool->lock());
if (!is_f1_null()) {
return;
}
const bool has_appendix = appendix.not_null();
const bool has_method_type = method_type.not_null();
// Write the flags.
set_method_flags(as_TosState(adapter->result_type()),
((has_appendix ? 1 : 0) << has_appendix_shift ) |
((has_method_type ? 1 : 0) << has_method_type_shift) |
( 1 << is_final_shift ),
adapter->size_of_parameters());
if (TraceInvokeDynamic) {
tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method_type="PTR_FORMAT"%s method="PTR_FORMAT" ",
invoke_code,
(intptr_t)appendix(), (has_appendix ? "" : " (unused)"),
(intptr_t)method_type(), (has_method_type ? "" : " (unused)"),
(intptr_t)adapter());
adapter->print();
if (has_appendix) appendix()->print();
}
// Method handle invokes and invokedynamic sites use both cp cache words.
// refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
// In the general case, this could be the call site's MethodType,
// for use with java.lang.Invokers.checkExactType, or else a CallSite object.
// f1 contains the adapter method which manages the actual call.
// In the general case, this is a compiled LambdaForm.
// (The Java code is free to optimize these calls by binding other
// sorts of methods and appendices to call sites.)
// JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
// The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
// Even with the appendix, the method will never take more than 255 parameter slots.
//
// This means that given a call site like (List)mh.invoke("foo"),
// the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
// not '(Ljava/lang/String;)Ljava/util/List;'.
// The fact that String and List are involved is encoded in the MethodType in refs[f2].
// This allows us to create fewer method oops, while keeping type safety.
//
// Store appendix, if any.
if (has_appendix) {
const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
resolved_references->obj_at_put(appendix_index, appendix());
}
// Store MethodType, if any.
if (has_method_type) {
const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
resolved_references->obj_at_put(method_type_index, method_type());
}
release_set_f1(adapter()); // This must be the last one to set (see NOTE above)!
// The interpreter assembly code does not check byte_2,
// but it is used by is_resolved, method_if_resolved, etc.
set_bytecode_1(invoke_code);
NOT_PRODUCT(verify(tty));
if (TraceInvokeDynamic) {
this->print(tty, 0);
}
}
Method* ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {
// Decode the action of set_method and set_interface_call
Bytecodes::Code invoke_code = bytecode_1();
if (invoke_code != (Bytecodes::Code)0) {
Metadata* f1 = (Metadata*)_f1;
if (f1 != NULL) {
switch (invoke_code) {
case Bytecodes::_invokeinterface:
assert(f1->is_klass(), "");
return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
case Bytecodes::_invokestatic:
case Bytecodes::_invokespecial:
assert(!has_appendix(), "");
case Bytecodes::_invokehandle:
case Bytecodes::_invokedynamic:
assert(f1->is_method(), "");
return (Method*)f1;
}
}
}
invoke_code = bytecode_2();
if (invoke_code != (Bytecodes::Code)0) {
switch (invoke_code) {
case Bytecodes::_invokevirtual:
if (is_vfinal()) {
// invokevirtual
Method* m = f2_as_vfinal_method();
assert(m->is_method(), "");
return m;
} else {
int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
if (cpool->tag_at(holder_index).is_klass()) {
Klass* klass = cpool->resolved_klass_at(holder_index);
if (!Klass::cast(klass)->oop_is_instance())
klass = SystemDictionary::Object_klass();
return InstanceKlass::cast(klass)->method_at_vtable(f2_as_index());
}
}
break;
}
}
return NULL;
}
oop ConstantPoolCacheEntry::appendix_if_resolved(constantPoolHandle cpool) {
if (is_f1_null() || !has_appendix())
return NULL;
const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
objArrayOop resolved_references = cpool->resolved_references();
return resolved_references->obj_at(ref_index);
}
oop ConstantPoolCacheEntry::method_type_if_resolved(constantPoolHandle cpool) {
if (is_f1_null() || !has_method_type())
return NULL;
const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
objArrayOop resolved_references = cpool->resolved_references();
return resolved_references->obj_at(ref_index);
}
// RedefineClasses() API support:
// If this constantPoolCacheEntry refers to old_method then update it
// to refer to new_method.
bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
Method* new_method, bool * trace_name_printed) {
if (is_vfinal()) {
// virtual and final so _f2 contains method ptr instead of vtable index
if (f2_as_vfinal_method() == old_method) {
// match old_method so need an update
// NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
_f2 = (intptr_t)new_method;
if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
if (!(*trace_name_printed)) {
// RC_TRACE_MESG macro has an embedded ResourceMark
RC_TRACE_MESG(("adjust: name=%s",
Klass::cast(old_method->method_holder())->external_name()));
*trace_name_printed = true;
}
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
new_method->name()->as_C_string(),
new_method->signature()->as_C_string()));
}
return true;
}
// f1() is not used with virtual entries so bail out
return false;
}
if (_f1 == NULL) {
// NULL f1() means this is a virtual entry so bail out
// We are assuming that the vtable index does not need change.
return false;
}
if (_f1 == old_method) {
_f1 = new_method;
if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
if (!(*trace_name_printed)) {
// RC_TRACE_MESG macro has an embedded ResourceMark
RC_TRACE_MESG(("adjust: name=%s",
Klass::cast(old_method->method_holder())->external_name()));
*trace_name_printed = true;
}
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
new_method->name()->as_C_string(),
new_method->signature()->as_C_string()));
}
return true;
}
return false;
}
#ifndef PRODUCT
bool ConstantPoolCacheEntry::check_no_old_entries() {
if (is_vfinal()) {
Metadata* f2 = (Metadata*)_f2;
return (f2->is_valid() && f2->is_method() && !((Method*)f2)->is_old());
} else {
return (_f1 == NULL || (_f1->is_valid() && _f1->is_method() && !((Method*)_f1)->is_old()));
}
}
#endif
bool ConstantPoolCacheEntry::is_interesting_method_entry(Klass* k) {
if (!is_method_entry()) {
// not a method entry so not interesting by default
return false;
}
Method* m = NULL;
if (is_vfinal()) {
// virtual and final so _f2 contains method ptr instead of vtable index
m = f2_as_vfinal_method();
} else if (is_f1_null()) {
// NULL _f1 means this is a virtual entry so also not interesting
return false;
} else {
if (!(_f1->is_method())) {
// _f1 can also contain a Klass* for an interface
return false;
}
m = f1_as_method();
}
assert(m != NULL && m->is_method(), "sanity check");
if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
// robustness for above sanity checks or method is not in
// the interesting class
return false;
}
// the method is in the interesting class so the entry is interesting
return true;
}
void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
// print separator
if (index == 0) st->print_cr(" -------------");
// print entry
st->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this);
st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());
st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f1);
st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2);
st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags);
st->print_cr(" -------------");
}
void ConstantPoolCacheEntry::verify(outputStream* st) const {
// not implemented yet
}
// Implementation of ConstantPoolCache
ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
int size = ConstantPoolCache::size(length);
return new (loader_data, size, false, THREAD) ConstantPoolCache(length);
}
void ConstantPoolCache::initialize(intArray& inverse_index_map, intArray& invokedynamic_references_map) {
assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");
for (int i = 0; i < length(); i++) {
ConstantPoolCacheEntry* e = entry_at(i);
int original_index = inverse_index_map[i];
e->initialize_entry(original_index);
assert(entry_at(i) == e, "sanity");
}
for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
const int cpci = invokedynamic_references_map[ref];
if (cpci >= 0) {
#ifdef ASSERT
// invokedynamic and invokehandle have more entries; check if they
// all point to the same constant pool cache entry.
for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
const int cpci_next = invokedynamic_references_map[ref + entry];
assert(cpci == cpci_next, err_msg_res("%d == %d", cpci, cpci_next));
}
#endif
entry_at(cpci)->initialize_resolved_reference_index(ref);
ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1; // skip extra entries
}
}
}
// RedefineClasses() API support:
// If any entry of this constantPoolCache points to any of
// old_methods, replace it with the corresponding new_method.
void ConstantPoolCache::adjust_method_entries(Method** old_methods, Method** new_methods,
int methods_length, bool * trace_name_printed) {
if (methods_length == 0) {
// nothing to do if there are no methods
return;
}
// get shorthand for the interesting class
Klass* old_holder = old_methods[0]->method_holder();
for (int i = 0; i < length(); i++) {
if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
// skip uninteresting methods
continue;
}
// The constantPoolCache contains entries for several different
// things, but we only care about methods. In fact, we only care
// about methods in the same class as the one that contains the
// old_methods. At this point, we have an interesting entry.
for (int j = 0; j < methods_length; j++) {
Method* old_method = old_methods[j];
Method* new_method = new_methods[j];
if (entry_at(i)->adjust_method_entry(old_method, new_method,
trace_name_printed)) {
// current old_method matched this entry and we updated it so
// break out and get to the next interesting entry if there one
break;
}
}
}
}
#ifndef PRODUCT
bool ConstantPoolCache::check_no_old_entries() {
for (int i = 1; i < length(); i++) {
if (entry_at(i)->is_interesting_method_entry(NULL) &&
!entry_at(i)->check_no_old_entries()) {
return false;
}
}
return true;
}
#endif // PRODUCT
// Printing
void ConstantPoolCache::print_on(outputStream* st) const {
assert(is_constantPoolCache(), "obj must be constant pool cache");
st->print_cr(internal_name());
// print constant pool cache entries
for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
}
void ConstantPoolCache::print_value_on(outputStream* st) const {
assert(is_constantPoolCache(), "obj must be constant pool cache");
st->print("cache [%d]", length());
print_address_on(st);
st->print(" for ");
constant_pool()->print_value_on(st);
}
// Verification
void ConstantPoolCache::verify_on(outputStream* st) {
guarantee(is_constantPoolCache(), "obj must be constant pool cache");
// print constant pool cache entries
for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
}