6935224: Adding new DTrace probes to work with Palantir
Summary: Adding probes related to thread scheduling and class initialization
Reviewed-by: kamg, never
/*
* Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
# include "incls/_precompiled.incl"
# include "incls/_instanceKlass.cpp.incl"
#ifdef DTRACE_ENABLED
HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
char*, intptr_t, oop, intptr_t);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
char*, intptr_t, oop, intptr_t, int);
HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
char*, intptr_t, oop, intptr_t, int);
#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type) \
{ \
char* data = NULL; \
int len = 0; \
symbolOop name = (clss)->name(); \
if (name != NULL) { \
data = (char*)name->bytes(); \
len = name->utf8_length(); \
} \
HS_DTRACE_PROBE4(hotspot, class__initialization__##type, \
data, len, (clss)->class_loader(), thread_type); \
}
#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
{ \
char* data = NULL; \
int len = 0; \
symbolOop name = (clss)->name(); \
if (name != NULL) { \
data = (char*)name->bytes(); \
len = name->utf8_length(); \
} \
HS_DTRACE_PROBE5(hotspot, class__initialization__##type, \
data, len, (clss)->class_loader(), thread_type, wait); \
}
#else // ndef DTRACE_ENABLED
#define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
#define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
#endif // ndef DTRACE_ENABLED
bool instanceKlass::should_be_initialized() const {
return !is_initialized();
}
klassVtable* instanceKlass::vtable() const {
return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size());
}
klassItable* instanceKlass::itable() const {
return new klassItable(as_klassOop());
}
void instanceKlass::eager_initialize(Thread *thread) {
if (!EagerInitialization) return;
if (this->is_not_initialized()) {
// abort if the the class has a class initializer
if (this->class_initializer() != NULL) return;
// abort if it is java.lang.Object (initialization is handled in genesis)
klassOop super = this->super();
if (super == NULL) return;
// abort if the super class should be initialized
if (!instanceKlass::cast(super)->is_initialized()) return;
// call body to expose the this pointer
instanceKlassHandle this_oop(thread, this->as_klassOop());
eager_initialize_impl(this_oop);
}
}
void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
EXCEPTION_MARK;
ObjectLocker ol(this_oop, THREAD);
// abort if someone beat us to the initialization
if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
ClassState old_state = this_oop->_init_state;
link_class_impl(this_oop, true, THREAD);
if (HAS_PENDING_EXCEPTION) {
CLEAR_PENDING_EXCEPTION;
// Abort if linking the class throws an exception.
// Use a test to avoid redundantly resetting the state if there's
// no change. Set_init_state() asserts that state changes make
// progress, whereas here we might just be spinning in place.
if( old_state != this_oop->_init_state )
this_oop->set_init_state (old_state);
} else {
// linking successfull, mark class as initialized
this_oop->set_init_state (fully_initialized);
// trace
if (TraceClassInitialization) {
ResourceMark rm(THREAD);
tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
}
}
}
// See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
// process. The step comments refers to the procedure described in that section.
// Note: implementation moved to static method to expose the this pointer.
void instanceKlass::initialize(TRAPS) {
if (this->should_be_initialized()) {
HandleMark hm(THREAD);
instanceKlassHandle this_oop(THREAD, this->as_klassOop());
initialize_impl(this_oop, CHECK);
// Note: at this point the class may be initialized
// OR it may be in the state of being initialized
// in case of recursive initialization!
} else {
assert(is_initialized(), "sanity check");
}
}
bool instanceKlass::verify_code(
instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
// 1) Verify the bytecodes
Verifier::Mode mode =
throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
}
// Used exclusively by the shared spaces dump mechanism to prevent
// classes mapped into the shared regions in new VMs from appearing linked.
void instanceKlass::unlink_class() {
assert(is_linked(), "must be linked");
_init_state = loaded;
}
void instanceKlass::link_class(TRAPS) {
assert(is_loaded(), "must be loaded");
if (!is_linked()) {
instanceKlassHandle this_oop(THREAD, this->as_klassOop());
link_class_impl(this_oop, true, CHECK);
}
}
// Called to verify that a class can link during initialization, without
// throwing a VerifyError.
bool instanceKlass::link_class_or_fail(TRAPS) {
assert(is_loaded(), "must be loaded");
if (!is_linked()) {
instanceKlassHandle this_oop(THREAD, this->as_klassOop());
link_class_impl(this_oop, false, CHECK_false);
}
return is_linked();
}
bool instanceKlass::link_class_impl(
instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
// check for error state
if (this_oop->is_in_error_state()) {
ResourceMark rm(THREAD);
THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
this_oop->external_name(), false);
}
// return if already verified
if (this_oop->is_linked()) {
return true;
}
// Timing
// timer handles recursion
assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
JavaThread* jt = (JavaThread*)THREAD;
// link super class before linking this class
instanceKlassHandle super(THREAD, this_oop->super());
if (super.not_null()) {
if (super->is_interface()) { // check if super class is an interface
ResourceMark rm(THREAD);
Exceptions::fthrow(
THREAD_AND_LOCATION,
vmSymbolHandles::java_lang_IncompatibleClassChangeError(),
"class %s has interface %s as super class",
this_oop->external_name(),
super->external_name()
);
return false;
}
link_class_impl(super, throw_verifyerror, CHECK_false);
}
// link all interfaces implemented by this class before linking this class
objArrayHandle interfaces (THREAD, this_oop->local_interfaces());
int num_interfaces = interfaces->length();
for (int index = 0; index < num_interfaces; index++) {
HandleMark hm(THREAD);
instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index)));
link_class_impl(ih, throw_verifyerror, CHECK_false);
}
// in case the class is linked in the process of linking its superclasses
if (this_oop->is_linked()) {
return true;
}
// trace only the link time for this klass that includes
// the verification time
PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
ClassLoader::perf_class_link_selftime(),
ClassLoader::perf_classes_linked(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_LINK);
// verification & rewriting
{
ObjectLocker ol(this_oop, THREAD);
// rewritten will have been set if loader constraint error found
// on an earlier link attempt
// don't verify or rewrite if already rewritten
if (!this_oop->is_linked()) {
if (!this_oop->is_rewritten()) {
{
// Timer includes any side effects of class verification (resolution,
// etc), but not recursive entry into verify_code().
PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
ClassLoader::perf_class_verify_selftime(),
ClassLoader::perf_classes_verified(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_VERIFY);
bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
if (!verify_ok) {
return false;
}
}
// Just in case a side-effect of verify linked this class already
// (which can sometimes happen since the verifier loads classes
// using custom class loaders, which are free to initialize things)
if (this_oop->is_linked()) {
return true;
}
// also sets rewritten
this_oop->rewrite_class(CHECK_false);
}
// Initialize the vtable and interface table after
// methods have been rewritten since rewrite may
// fabricate new methodOops.
// also does loader constraint checking
if (!this_oop()->is_shared()) {
ResourceMark rm(THREAD);
this_oop->vtable()->initialize_vtable(true, CHECK_false);
this_oop->itable()->initialize_itable(true, CHECK_false);
}
#ifdef ASSERT
else {
ResourceMark rm(THREAD);
this_oop->vtable()->verify(tty, true);
// In case itable verification is ever added.
// this_oop->itable()->verify(tty, true);
}
#endif
this_oop->set_init_state(linked);
if (JvmtiExport::should_post_class_prepare()) {
Thread *thread = THREAD;
assert(thread->is_Java_thread(), "thread->is_Java_thread()");
JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
}
}
}
return true;
}
// Rewrite the byte codes of all of the methods of a class.
// Three cases:
// During the link of a newly loaded class.
// During the preloading of classes to be written to the shared spaces.
// - Rewrite the methods and update the method entry points.
//
// During the link of a class in the shared spaces.
// - The methods were already rewritten, update the metho entry points.
//
// The rewriter must be called exactly once. Rewriting must happen after
// verification but before the first method of the class is executed.
void instanceKlass::rewrite_class(TRAPS) {
assert(is_loaded(), "must be loaded");
instanceKlassHandle this_oop(THREAD, this->as_klassOop());
if (this_oop->is_rewritten()) {
assert(this_oop()->is_shared(), "rewriting an unshared class?");
return;
}
Rewriter::rewrite(this_oop, CHECK); // No exception can happen here
this_oop->set_rewritten();
}
void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
// Make sure klass is linked (verified) before initialization
// A class could already be verified, since it has been reflected upon.
this_oop->link_class(CHECK);
DTRACE_CLASSINIT_PROBE(required, instanceKlass::cast(this_oop()), -1);
bool wait = false;
// refer to the JVM book page 47 for description of steps
// Step 1
{ ObjectLocker ol(this_oop, THREAD);
Thread *self = THREAD; // it's passed the current thread
// Step 2
// If we were to use wait() instead of waitInterruptibly() then
// we might end up throwing IE from link/symbol resolution sites
// that aren't expected to throw. This would wreak havoc. See 6320309.
while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
wait = true;
ol.waitUninterruptibly(CHECK);
}
// Step 3
if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
DTRACE_CLASSINIT_PROBE_WAIT(recursive, instanceKlass::cast(this_oop()), -1,wait);
return;
}
// Step 4
if (this_oop->is_initialized()) {
DTRACE_CLASSINIT_PROBE_WAIT(concurrent, instanceKlass::cast(this_oop()), -1,wait);
return;
}
// Step 5
if (this_oop->is_in_error_state()) {
DTRACE_CLASSINIT_PROBE_WAIT(erroneous, instanceKlass::cast(this_oop()), -1,wait);
ResourceMark rm(THREAD);
const char* desc = "Could not initialize class ";
const char* className = this_oop->external_name();
size_t msglen = strlen(desc) + strlen(className) + 1;
char* message = NEW_C_HEAP_ARRAY(char, msglen);
if (NULL == message) {
// Out of memory: can't create detailed error message
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
} else {
jio_snprintf(message, msglen, "%s%s", desc, className);
THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
}
}
// Step 6
this_oop->set_init_state(being_initialized);
this_oop->set_init_thread(self);
}
// Step 7
klassOop super_klass = this_oop->super();
if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
Klass::cast(super_klass)->initialize(THREAD);
if (HAS_PENDING_EXCEPTION) {
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
{
EXCEPTION_MARK;
this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, superclass initialization error is thrown below
}
DTRACE_CLASSINIT_PROBE_WAIT(super__failed, instanceKlass::cast(this_oop()), -1,wait);
THROW_OOP(e());
}
}
// Step 8
{
assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
JavaThread* jt = (JavaThread*)THREAD;
DTRACE_CLASSINIT_PROBE_WAIT(clinit, instanceKlass::cast(this_oop()), -1,wait);
// Timer includes any side effects of class initialization (resolution,
// etc), but not recursive entry into call_class_initializer().
PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
ClassLoader::perf_class_init_selftime(),
ClassLoader::perf_classes_inited(),
jt->get_thread_stat()->perf_recursion_counts_addr(),
jt->get_thread_stat()->perf_timers_addr(),
PerfClassTraceTime::CLASS_CLINIT);
this_oop->call_class_initializer(THREAD);
}
// Step 9
if (!HAS_PENDING_EXCEPTION) {
this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
{ ResourceMark rm(THREAD);
debug_only(this_oop->vtable()->verify(tty, true);)
}
}
else {
// Step 10 and 11
Handle e(THREAD, PENDING_EXCEPTION);
CLEAR_PENDING_EXCEPTION;
{
EXCEPTION_MARK;
this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
CLEAR_PENDING_EXCEPTION; // ignore any exception thrown, class initialization error is thrown below
}
DTRACE_CLASSINIT_PROBE_WAIT(error, instanceKlass::cast(this_oop()), -1,wait);
if (e->is_a(SystemDictionary::Error_klass())) {
THROW_OOP(e());
} else {
JavaCallArguments args(e);
THROW_ARG(vmSymbolHandles::java_lang_ExceptionInInitializerError(),
vmSymbolHandles::throwable_void_signature(),
&args);
}
}
DTRACE_CLASSINIT_PROBE_WAIT(end, instanceKlass::cast(this_oop()), -1,wait);
}
// Note: implementation moved to static method to expose the this pointer.
void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
instanceKlassHandle kh(THREAD, this->as_klassOop());
set_initialization_state_and_notify_impl(kh, state, CHECK);
}
void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
ObjectLocker ol(this_oop, THREAD);
this_oop->set_init_state(state);
ol.notify_all(CHECK);
}
void instanceKlass::add_implementor(klassOop k) {
assert(Compile_lock->owned_by_self(), "");
// Filter out my subinterfaces.
// (Note: Interfaces are never on the subklass list.)
if (instanceKlass::cast(k)->is_interface()) return;
// Filter out subclasses whose supers already implement me.
// (Note: CHA must walk subclasses of direct implementors
// in order to locate indirect implementors.)
klassOop sk = instanceKlass::cast(k)->super();
if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop()))
// We only need to check one immediate superclass, since the
// implements_interface query looks at transitive_interfaces.
// Any supers of the super have the same (or fewer) transitive_interfaces.
return;
// Update number of implementors
int i = _nof_implementors++;
// Record this implementor, if there are not too many already
if (i < implementors_limit) {
assert(_implementors[i] == NULL, "should be exactly one implementor");
oop_store_without_check((oop*)&_implementors[i], k);
} else if (i == implementors_limit) {
// clear out the list on first overflow
for (int i2 = 0; i2 < implementors_limit; i2++)
oop_store_without_check((oop*)&_implementors[i2], NULL);
}
// The implementor also implements the transitive_interfaces
for (int index = 0; index < local_interfaces()->length(); index++) {
instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k);
}
}
void instanceKlass::init_implementor() {
for (int i = 0; i < implementors_limit; i++)
oop_store_without_check((oop*)&_implementors[i], NULL);
_nof_implementors = 0;
}
void instanceKlass::process_interfaces(Thread *thread) {
// link this class into the implementors list of every interface it implements
KlassHandle this_as_oop (thread, this->as_klassOop());
for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass");
instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i)));
assert(interf->is_interface(), "expected interface");
interf->add_implementor(this_as_oop());
}
}
bool instanceKlass::can_be_primary_super_slow() const {
if (is_interface())
return false;
else
return Klass::can_be_primary_super_slow();
}
objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
// The secondaries are the implemented interfaces.
instanceKlass* ik = instanceKlass::cast(as_klassOop());
objArrayHandle interfaces (THREAD, ik->transitive_interfaces());
int num_secondaries = num_extra_slots + interfaces->length();
if (num_secondaries == 0) {
return Universe::the_empty_system_obj_array();
} else if (num_extra_slots == 0) {
return interfaces();
} else {
// a mix of both
objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL);
for (int i = 0; i < interfaces->length(); i++) {
secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i));
}
return secondaries;
}
}
bool instanceKlass::compute_is_subtype_of(klassOop k) {
if (Klass::cast(k)->is_interface()) {
return implements_interface(k);
} else {
return Klass::compute_is_subtype_of(k);
}
}
bool instanceKlass::implements_interface(klassOop k) const {
if (as_klassOop() == k) return true;
assert(Klass::cast(k)->is_interface(), "should be an interface class");
for (int i = 0; i < transitive_interfaces()->length(); i++) {
if (transitive_interfaces()->obj_at(i) == k) {
return true;
}
}
return false;
}
objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
report_java_out_of_memory("Requested array size exceeds VM limit");
THROW_OOP_0(Universe::out_of_memory_error_array_size());
}
int size = objArrayOopDesc::object_size(length);
klassOop ak = array_klass(n, CHECK_NULL);
KlassHandle h_ak (THREAD, ak);
objArrayOop o =
(objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
return o;
}
instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) {
if (TraceFinalizerRegistration) {
tty->print("Registered ");
i->print_value_on(tty);
tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
}
instanceHandle h_i(THREAD, i);
// Pass the handle as argument, JavaCalls::call expects oop as jobjects
JavaValue result(T_VOID);
JavaCallArguments args(h_i);
methodHandle mh (THREAD, Universe::finalizer_register_method());
JavaCalls::call(&result, mh, &args, CHECK_NULL);
return h_i();
}
instanceOop instanceKlass::allocate_instance(TRAPS) {
bool has_finalizer_flag = has_finalizer(); // Query before possible GC
int size = size_helper(); // Query before forming handle.
KlassHandle h_k(THREAD, as_klassOop());
instanceOop i;
i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
if (has_finalizer_flag && !RegisterFinalizersAtInit) {
i = register_finalizer(i, CHECK_NULL);
}
return i;
}
instanceOop instanceKlass::allocate_permanent_instance(TRAPS) {
// Finalizer registration occurs in the Object.<init> constructor
// and constructors normally aren't run when allocating perm
// instances so simply disallow finalizable perm objects. This can
// be relaxed if a need for it is found.
assert(!has_finalizer(), "perm objects not allowed to have finalizers");
int size = size_helper(); // Query before forming handle.
KlassHandle h_k(THREAD, as_klassOop());
instanceOop i = (instanceOop)
CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
return i;
}
void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
if (is_interface() || is_abstract()) {
ResourceMark rm(THREAD);
THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
: vmSymbols::java_lang_InstantiationException(), external_name());
}
if (as_klassOop() == SystemDictionary::Class_klass()) {
ResourceMark rm(THREAD);
THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
: vmSymbols::java_lang_IllegalAccessException(), external_name());
}
}
klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
instanceKlassHandle this_oop(THREAD, as_klassOop());
return array_klass_impl(this_oop, or_null, n, THREAD);
}
klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
if (this_oop->array_klasses() == NULL) {
if (or_null) return NULL;
ResourceMark rm;
JavaThread *jt = (JavaThread *)THREAD;
{
// Atomic creation of array_klasses
MutexLocker mc(Compile_lock, THREAD); // for vtables
MutexLocker ma(MultiArray_lock, THREAD);
// Check if update has already taken place
if (this_oop->array_klasses() == NULL) {
objArrayKlassKlass* oakk =
(objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part();
klassOop k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL);
this_oop->set_array_klasses(k);
}
}
}
// _this will always be set at this point
objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part();
if (or_null) {
return oak->array_klass_or_null(n);
}
return oak->array_klass(n, CHECK_NULL);
}
klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) {
return array_klass_impl(or_null, 1, THREAD);
}
void instanceKlass::call_class_initializer(TRAPS) {
instanceKlassHandle ik (THREAD, as_klassOop());
call_class_initializer_impl(ik, THREAD);
}
static int call_class_initializer_impl_counter = 0; // for debugging
methodOop instanceKlass::class_initializer() {
return find_method(vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
}
void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
methodHandle h_method(THREAD, this_oop->class_initializer());
assert(!this_oop->is_initialized(), "we cannot initialize twice");
if (TraceClassInitialization) {
tty->print("%d Initializing ", call_class_initializer_impl_counter++);
this_oop->name()->print_value();
tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
}
if (h_method() != NULL) {
JavaCallArguments args; // No arguments
JavaValue result(T_VOID);
JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
}
}
void instanceKlass::mask_for(methodHandle method, int bci,
InterpreterOopMap* entry_for) {
// Dirty read, then double-check under a lock.
if (_oop_map_cache == NULL) {
// Otherwise, allocate a new one.
MutexLocker x(OopMapCacheAlloc_lock);
// First time use. Allocate a cache in C heap
if (_oop_map_cache == NULL) {
_oop_map_cache = new OopMapCache();
}
}
// _oop_map_cache is constant after init; lookup below does is own locking.
_oop_map_cache->lookup(method, bci, entry_for);
}
bool instanceKlass::find_local_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const {
const int n = fields()->length();
for (int i = 0; i < n; i += next_offset ) {
int name_index = fields()->ushort_at(i + name_index_offset);
int sig_index = fields()->ushort_at(i + signature_index_offset);
symbolOop f_name = constants()->symbol_at(name_index);
symbolOop f_sig = constants()->symbol_at(sig_index);
if (f_name == name && f_sig == sig) {
fd->initialize(as_klassOop(), i);
return true;
}
}
return false;
}
void instanceKlass::field_names_and_sigs_iterate(OopClosure* closure) {
const int n = fields()->length();
for (int i = 0; i < n; i += next_offset ) {
int name_index = fields()->ushort_at(i + name_index_offset);
symbolOop name = constants()->symbol_at(name_index);
closure->do_oop((oop*)&name);
int sig_index = fields()->ushort_at(i + signature_index_offset);
symbolOop sig = constants()->symbol_at(sig_index);
closure->do_oop((oop*)&sig);
}
}
klassOop instanceKlass::find_interface_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const {
const int n = local_interfaces()->length();
for (int i = 0; i < n; i++) {
klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
assert(Klass::cast(intf1)->is_interface(), "just checking type");
// search for field in current interface
if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
assert(fd->is_static(), "interface field must be static");
return intf1;
}
// search for field in direct superinterfaces
klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
if (intf2 != NULL) return intf2;
}
// otherwise field lookup fails
return NULL;
}
klassOop instanceKlass::find_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const {
// search order according to newest JVM spec (5.4.3.2, p.167).
// 1) search for field in current klass
if (find_local_field(name, sig, fd)) {
return as_klassOop();
}
// 2) search for field recursively in direct superinterfaces
{ klassOop intf = find_interface_field(name, sig, fd);
if (intf != NULL) return intf;
}
// 3) apply field lookup recursively if superclass exists
{ klassOop supr = super();
if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
}
// 4) otherwise field lookup fails
return NULL;
}
klassOop instanceKlass::find_field(symbolOop name, symbolOop sig, bool is_static, fieldDescriptor* fd) const {
// search order according to newest JVM spec (5.4.3.2, p.167).
// 1) search for field in current klass
if (find_local_field(name, sig, fd)) {
if (fd->is_static() == is_static) return as_klassOop();
}
// 2) search for field recursively in direct superinterfaces
if (is_static) {
klassOop intf = find_interface_field(name, sig, fd);
if (intf != NULL) return intf;
}
// 3) apply field lookup recursively if superclass exists
{ klassOop supr = super();
if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
}
// 4) otherwise field lookup fails
return NULL;
}
bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
int length = fields()->length();
for (int i = 0; i < length; i += next_offset) {
if (offset_from_fields( i ) == offset) {
fd->initialize(as_klassOop(), i);
if (fd->is_static() == is_static) return true;
}
}
return false;
}
bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
klassOop klass = as_klassOop();
while (klass != NULL) {
if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
return true;
}
klass = Klass::cast(klass)->super();
}
return false;
}
void instanceKlass::methods_do(void f(methodOop method)) {
int len = methods()->length();
for (int index = 0; index < len; index++) {
methodOop m = methodOop(methods()->obj_at(index));
assert(m->is_method(), "must be method");
f(m);
}
}
void instanceKlass::do_local_static_fields(FieldClosure* cl) {
fieldDescriptor fd;
int length = fields()->length();
for (int i = 0; i < length; i += next_offset) {
fd.initialize(as_klassOop(), i);
if (fd.is_static()) cl->do_field(&fd);
}
}
void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
instanceKlassHandle h_this(THREAD, as_klassOop());
do_local_static_fields_impl(h_this, f, CHECK);
}
void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
fieldDescriptor fd;
int length = this_oop->fields()->length();
for (int i = 0; i < length; i += next_offset) {
fd.initialize(this_oop(), i);
if (fd.is_static()) { f(&fd, CHECK); } // Do NOT remove {}! (CHECK macro expands into several statements)
}
}
static int compare_fields_by_offset(int* a, int* b) {
return a[0] - b[0];
}
void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
instanceKlass* super = superklass();
if (super != NULL) {
super->do_nonstatic_fields(cl);
}
fieldDescriptor fd;
int length = fields()->length();
// In DebugInfo nonstatic fields are sorted by offset.
int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1));
int j = 0;
for (int i = 0; i < length; i += next_offset) {
fd.initialize(as_klassOop(), i);
if (!fd.is_static()) {
fields_sorted[j + 0] = fd.offset();
fields_sorted[j + 1] = i;
j += 2;
}
}
if (j > 0) {
length = j;
// _sort_Fn is defined in growableArray.hpp.
qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
for (int i = 0; i < length; i += 2) {
fd.initialize(as_klassOop(), fields_sorted[i + 1]);
assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
cl->do_field(&fd);
}
}
FREE_C_HEAP_ARRAY(int, fields_sorted);
}
void instanceKlass::array_klasses_do(void f(klassOop k)) {
if (array_klasses() != NULL)
arrayKlass::cast(array_klasses())->array_klasses_do(f);
}
void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
f(as_klassOop());
array_klasses_do(f);
}
#ifdef ASSERT
static int linear_search(objArrayOop methods, symbolOop name, symbolOop signature) {
int len = methods->length();
for (int index = 0; index < len; index++) {
methodOop m = (methodOop)(methods->obj_at(index));
assert(m->is_method(), "must be method");
if (m->signature() == signature && m->name() == name) {
return index;
}
}
return -1;
}
#endif
methodOop instanceKlass::find_method(symbolOop name, symbolOop signature) const {
return instanceKlass::find_method(methods(), name, signature);
}
methodOop instanceKlass::find_method(objArrayOop methods, symbolOop name, symbolOop signature) {
int len = methods->length();
// methods are sorted, so do binary search
int l = 0;
int h = len - 1;
while (l <= h) {
int mid = (l + h) >> 1;
methodOop m = (methodOop)methods->obj_at(mid);
assert(m->is_method(), "must be method");
int res = m->name()->fast_compare(name);
if (res == 0) {
// found matching name; do linear search to find matching signature
// first, quick check for common case
if (m->signature() == signature) return m;
// search downwards through overloaded methods
int i;
for (i = mid - 1; i >= l; i--) {
methodOop m = (methodOop)methods->obj_at(i);
assert(m->is_method(), "must be method");
if (m->name() != name) break;
if (m->signature() == signature) return m;
}
// search upwards
for (i = mid + 1; i <= h; i++) {
methodOop m = (methodOop)methods->obj_at(i);
assert(m->is_method(), "must be method");
if (m->name() != name) break;
if (m->signature() == signature) return m;
}
// not found
#ifdef ASSERT
int index = linear_search(methods, name, signature);
if (index != -1) fatal1("binary search bug: should have found entry %d", index);
#endif
return NULL;
} else if (res < 0) {
l = mid + 1;
} else {
h = mid - 1;
}
}
#ifdef ASSERT
int index = linear_search(methods, name, signature);
if (index != -1) fatal1("binary search bug: should have found entry %d", index);
#endif
return NULL;
}
methodOop instanceKlass::uncached_lookup_method(symbolOop name, symbolOop signature) const {
klassOop klass = as_klassOop();
while (klass != NULL) {
methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
if (method != NULL) return method;
klass = instanceKlass::cast(klass)->super();
}
return NULL;
}
// lookup a method in all the interfaces that this class implements
methodOop instanceKlass::lookup_method_in_all_interfaces(symbolOop name,
symbolOop signature) const {
objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
int num_ifs = all_ifs->length();
instanceKlass *ik = NULL;
for (int i = 0; i < num_ifs; i++) {
ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
methodOop m = ik->lookup_method(name, signature);
if (m != NULL) {
return m;
}
}
return NULL;
}
/* jni_id_for_impl for jfieldIds only */
JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
MutexLocker ml(JfieldIdCreation_lock);
// Retry lookup after we got the lock
JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
if (probe == NULL) {
// Slow case, allocate new static field identifier
probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
this_oop->set_jni_ids(probe);
}
return probe;
}
/* jni_id_for for jfieldIds only */
JNIid* instanceKlass::jni_id_for(int offset) {
JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
if (probe == NULL) {
probe = jni_id_for_impl(this->as_klassOop(), offset);
}
return probe;
}
// Lookup or create a jmethodID.
// This code is called by the VMThread and JavaThreads so the
// locking has to be done very carefully to avoid deadlocks
// and/or other cache consistency problems.
//
jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
size_t idnum = (size_t)method_h->method_idnum();
jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
size_t length = 0;
jmethodID id = NULL;
// We use a double-check locking idiom here because this cache is
// performance sensitive. In the normal system, this cache only
// transitions from NULL to non-NULL which is safe because we use
// release_set_methods_jmethod_ids() to advertise the new cache.
// A partially constructed cache should never be seen by a racing
// thread. We also use release_store_ptr() to save a new jmethodID
// in the cache so a partially constructed jmethodID should never be
// seen either. Cache reads of existing jmethodIDs proceed without a
// lock, but cache writes of a new jmethodID requires uniqueness and
// creation of the cache itself requires no leaks so a lock is
// generally acquired in those two cases.
//
// If the RedefineClasses() API has been used, then this cache can
// grow and we'll have transitions from non-NULL to bigger non-NULL.
// Cache creation requires no leaks and we require safety between all
// cache accesses and freeing of the old cache so a lock is generally
// acquired when the RedefineClasses() API has been used.
if (jmeths != NULL) {
// the cache already exists
if (!ik_h->idnum_can_increment()) {
// the cache can't grow so we can just get the current values
get_jmethod_id_length_value(jmeths, idnum, &length, &id);
} else {
// cache can grow so we have to be more careful
if (Threads::number_of_threads() == 0 ||
SafepointSynchronize::is_at_safepoint()) {
// we're single threaded or at a safepoint - no locking needed
get_jmethod_id_length_value(jmeths, idnum, &length, &id);
} else {
MutexLocker ml(JmethodIdCreation_lock);
get_jmethod_id_length_value(jmeths, idnum, &length, &id);
}
}
}
// implied else:
// we need to allocate a cache so default length and id values are good
if (jmeths == NULL || // no cache yet
length <= idnum || // cache is too short
id == NULL) { // cache doesn't contain entry
// This function can be called by the VMThread so we have to do all
// things that might block on a safepoint before grabbing the lock.
// Otherwise, we can deadlock with the VMThread or have a cache
// consistency issue. These vars keep track of what we might have
// to free after the lock is dropped.
jmethodID to_dealloc_id = NULL;
jmethodID* to_dealloc_jmeths = NULL;
// may not allocate new_jmeths or use it if we allocate it
jmethodID* new_jmeths = NULL;
if (length <= idnum) {
// allocate a new cache that might be used
size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1);
memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
// cache size is stored in element[0], other elements offset by one
new_jmeths[0] = (jmethodID)size;
}
// allocate a new jmethodID that might be used
jmethodID new_id = NULL;
if (method_h->is_old() && !method_h->is_obsolete()) {
// The method passed in is old (but not obsolete), we need to use the current version
methodOop current_method = ik_h->method_with_idnum((int)idnum);
assert(current_method != NULL, "old and but not obsolete, so should exist");
methodHandle current_method_h(current_method == NULL? method_h() : current_method);
new_id = JNIHandles::make_jmethod_id(current_method_h);
} else {
// It is the current version of the method or an obsolete method,
// use the version passed in
new_id = JNIHandles::make_jmethod_id(method_h);
}
if (Threads::number_of_threads() == 0 ||
SafepointSynchronize::is_at_safepoint()) {
// we're single threaded or at a safepoint - no locking needed
id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
&to_dealloc_id, &to_dealloc_jmeths);
} else {
MutexLocker ml(JmethodIdCreation_lock);
id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
&to_dealloc_id, &to_dealloc_jmeths);
}
// The lock has been dropped so we can free resources.
// Free up either the old cache or the new cache if we allocated one.
if (to_dealloc_jmeths != NULL) {
FreeHeap(to_dealloc_jmeths);
}
// free up the new ID since it wasn't needed
if (to_dealloc_id != NULL) {
JNIHandles::destroy_jmethod_id(to_dealloc_id);
}
}
return id;
}
// Common code to fetch the jmethodID from the cache or update the
// cache with the new jmethodID. This function should never do anything
// that causes the caller to go to a safepoint or we can deadlock with
// the VMThread or have cache consistency issues.
//
jmethodID instanceKlass::get_jmethod_id_fetch_or_update(
instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
jmethodID** to_dealloc_jmeths_p) {
assert(new_id != NULL, "sanity check");
assert(to_dealloc_id_p != NULL, "sanity check");
assert(to_dealloc_jmeths_p != NULL, "sanity check");
assert(Threads::number_of_threads() == 0 ||
SafepointSynchronize::is_at_safepoint() ||
JmethodIdCreation_lock->owned_by_self(), "sanity check");
// reacquire the cache - we are locked, single threaded or at a safepoint
jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
jmethodID id = NULL;
size_t length = 0;
if (jmeths == NULL || // no cache yet
(length = (size_t)jmeths[0]) <= idnum) { // cache is too short
if (jmeths != NULL) {
// copy any existing entries from the old cache
for (size_t index = 0; index < length; index++) {
new_jmeths[index+1] = jmeths[index+1];
}
*to_dealloc_jmeths_p = jmeths; // save old cache for later delete
}
ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
} else {
// fetch jmethodID (if any) from the existing cache
id = jmeths[idnum+1];
*to_dealloc_jmeths_p = new_jmeths; // save new cache for later delete
}
if (id == NULL) {
// No matching jmethodID in the existing cache or we have a new
// cache or we just grew the cache. This cache write is done here
// by the first thread to win the foot race because a jmethodID
// needs to be unique once it is generally available.
id = new_id;
// The jmethodID cache can be read while unlocked so we have to
// make sure the new jmethodID is complete before installing it
// in the cache.
OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
} else {
*to_dealloc_id_p = new_id; // save new id for later delete
}
return id;
}
// Common code to get the jmethodID cache length and the jmethodID
// value at index idnum if there is one.
//
void instanceKlass::get_jmethod_id_length_value(jmethodID* cache,
size_t idnum, size_t *length_p, jmethodID* id_p) {
assert(cache != NULL, "sanity check");
assert(length_p != NULL, "sanity check");
assert(id_p != NULL, "sanity check");
// cache size is stored in element[0], other elements offset by one
*length_p = (size_t)cache[0];
if (*length_p <= idnum) { // cache is too short
*id_p = NULL;
} else {
*id_p = cache[idnum+1]; // fetch jmethodID (if any)
}
}
// Lookup a jmethodID, NULL if not found. Do no blocking, no allocations, no handles
jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
size_t idnum = (size_t)method->method_idnum();
jmethodID* jmeths = methods_jmethod_ids_acquire();
size_t length; // length assigned as debugging crumb
jmethodID id = NULL;
if (jmeths != NULL && // If there is a cache
(length = (size_t)jmeths[0]) > idnum) { // and if it is long enough,
id = jmeths[idnum+1]; // Look up the id (may be NULL)
}
return id;
}
// Cache an itable index
void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
int* indices = methods_cached_itable_indices_acquire();
int* to_dealloc_indices = NULL;
// We use a double-check locking idiom here because this cache is
// performance sensitive. In the normal system, this cache only
// transitions from NULL to non-NULL which is safe because we use
// release_set_methods_cached_itable_indices() to advertise the
// new cache. A partially constructed cache should never be seen
// by a racing thread. Cache reads and writes proceed without a
// lock, but creation of the cache itself requires no leaks so a
// lock is generally acquired in that case.
//
// If the RedefineClasses() API has been used, then this cache can
// grow and we'll have transitions from non-NULL to bigger non-NULL.
// Cache creation requires no leaks and we require safety between all
// cache accesses and freeing of the old cache so a lock is generally
// acquired when the RedefineClasses() API has been used.
if (indices == NULL || idnum_can_increment()) {
// we need a cache or the cache can grow
MutexLocker ml(JNICachedItableIndex_lock);
// reacquire the cache to see if another thread already did the work
indices = methods_cached_itable_indices_acquire();
size_t length = 0;
// cache size is stored in element[0], other elements offset by one
if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
int* new_indices = NEW_C_HEAP_ARRAY(int, size+1);
new_indices[0] = (int)size;
// copy any existing entries
size_t i;
for (i = 0; i < length; i++) {
new_indices[i+1] = indices[i+1];
}
// Set all the rest to -1
for (i = length; i < size; i++) {
new_indices[i+1] = -1;
}
if (indices != NULL) {
// We have an old cache to delete so save it for after we
// drop the lock.
to_dealloc_indices = indices;
}
release_set_methods_cached_itable_indices(indices = new_indices);
}
if (idnum_can_increment()) {
// this cache can grow so we have to write to it safely
indices[idnum+1] = index;
}
} else {
CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
}
if (!idnum_can_increment()) {
// The cache cannot grow and this JNI itable index value does not
// have to be unique like a jmethodID. If there is a race to set it,
// it doesn't matter.
indices[idnum+1] = index;
}
if (to_dealloc_indices != NULL) {
// we allocated a new cache so free the old one
FreeHeap(to_dealloc_indices);
}
}
// Retrieve a cached itable index
int instanceKlass::cached_itable_index(size_t idnum) {
int* indices = methods_cached_itable_indices_acquire();
if (indices != NULL && ((size_t)indices[0]) > idnum) {
// indices exist and are long enough, retrieve possible cached
return indices[idnum+1];
}
return -1;
}
//
// nmethodBucket is used to record dependent nmethods for
// deoptimization. nmethod dependencies are actually <klass, method>
// pairs but we really only care about the klass part for purposes of
// finding nmethods which might need to be deoptimized. Instead of
// recording the method, a count of how many times a particular nmethod
// was recorded is kept. This ensures that any recording errors are
// noticed since an nmethod should be removed as many times are it's
// added.
//
class nmethodBucket {
private:
nmethod* _nmethod;
int _count;
nmethodBucket* _next;
public:
nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
_nmethod = nmethod;
_next = next;
_count = 1;
}
int count() { return _count; }
int increment() { _count += 1; return _count; }
int decrement() { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
nmethodBucket* next() { return _next; }
void set_next(nmethodBucket* b) { _next = b; }
nmethod* get_nmethod() { return _nmethod; }
};
//
// Walk the list of dependent nmethods searching for nmethods which
// are dependent on the klassOop that was passed in and mark them for
// deoptimization. Returns the number of nmethods found.
//
int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
assert_locked_or_safepoint(CodeCache_lock);
int found = 0;
nmethodBucket* b = _dependencies;
while (b != NULL) {
nmethod* nm = b->get_nmethod();
// since dependencies aren't removed until an nmethod becomes a zombie,
// the dependency list may contain nmethods which aren't alive.
if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
if (TraceDependencies) {
ResourceMark rm;
tty->print_cr("Marked for deoptimization");
tty->print_cr(" context = %s", this->external_name());
changes.print();
nm->print();
nm->print_dependencies();
}
nm->mark_for_deoptimization();
found++;
}
b = b->next();
}
return found;
}
//
// Add an nmethodBucket to the list of dependencies for this nmethod.
// It's possible that an nmethod has multiple dependencies on this klass
// so a count is kept for each bucket to guarantee that creation and
// deletion of dependencies is consistent.
//
void instanceKlass::add_dependent_nmethod(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
nmethodBucket* b = _dependencies;
nmethodBucket* last = NULL;
while (b != NULL) {
if (nm == b->get_nmethod()) {
b->increment();
return;
}
b = b->next();
}
_dependencies = new nmethodBucket(nm, _dependencies);
}
//
// Decrement count of the nmethod in the dependency list and remove
// the bucket competely when the count goes to 0. This method must
// find a corresponding bucket otherwise there's a bug in the
// recording of dependecies.
//
void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
nmethodBucket* b = _dependencies;
nmethodBucket* last = NULL;
while (b != NULL) {
if (nm == b->get_nmethod()) {
if (b->decrement() == 0) {
if (last == NULL) {
_dependencies = b->next();
} else {
last->set_next(b->next());
}
delete b;
}
return;
}
last = b;
b = b->next();
}
#ifdef ASSERT
tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
nm->print();
#endif // ASSERT
ShouldNotReachHere();
}
#ifndef PRODUCT
void instanceKlass::print_dependent_nmethods(bool verbose) {
nmethodBucket* b = _dependencies;
int idx = 0;
while (b != NULL) {
nmethod* nm = b->get_nmethod();
tty->print("[%d] count=%d { ", idx++, b->count());
if (!verbose) {
nm->print_on(tty, "nmethod");
tty->print_cr(" } ");
} else {
nm->print();
nm->print_dependencies();
tty->print_cr("--- } ");
}
b = b->next();
}
}
bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
nmethodBucket* b = _dependencies;
while (b != NULL) {
if (nm == b->get_nmethod()) {
return true;
}
b = b->next();
}
return false;
}
#endif //PRODUCT
#ifdef ASSERT
template <class T> void assert_is_in(T *p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(Universe::heap()->is_in(o), "should be in heap");
}
}
template <class T> void assert_is_in_closed_subset(T *p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
}
}
template <class T> void assert_is_in_reserved(T *p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
}
}
template <class T> void assert_nothing(T *p) {}
#else
template <class T> void assert_is_in(T *p) {}
template <class T> void assert_is_in_closed_subset(T *p) {}
template <class T> void assert_is_in_reserved(T *p) {}
template <class T> void assert_nothing(T *p) {}
#endif // ASSERT
//
// Macros that iterate over areas of oops which are specialized on type of
// oop pointer either narrow or wide, depending on UseCompressedOops
//
// Parameters are:
// T - type of oop to point to (either oop or narrowOop)
// start_p - starting pointer for region to iterate over
// count - number of oops or narrowOops to iterate over
// do_oop - action to perform on each oop (it's arbitrary C code which
// makes it more efficient to put in a macro rather than making
// it a template function)
// assert_fn - assert function which is template function because performance
// doesn't matter when enabled.
#define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
T, start_p, count, do_oop, \
assert_fn) \
{ \
T* p = (T*)(start_p); \
T* const end = p + (count); \
while (p < end) { \
(assert_fn)(p); \
do_oop; \
++p; \
} \
}
#define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
T, start_p, count, do_oop, \
assert_fn) \
{ \
T* const start = (T*)(start_p); \
T* p = start + (count); \
while (start < p) { \
--p; \
(assert_fn)(p); \
do_oop; \
} \
}
#define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
T, start_p, count, low, high, \
do_oop, assert_fn) \
{ \
T* const l = (T*)(low); \
T* const h = (T*)(high); \
assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
mask_bits((intptr_t)h, sizeof(T)-1) == 0, \
"bounded region must be properly aligned"); \
T* p = (T*)(start_p); \
T* end = p + (count); \
if (p < l) p = l; \
if (end > h) end = h; \
while (p < end) { \
(assert_fn)(p); \
do_oop; \
++p; \
} \
}
// The following macros call specialized macros, passing either oop or
// narrowOop as the specialization type. These test the UseCompressedOops
// flag.
#define InstanceKlass_OOP_ITERATE(start_p, count, \
do_oop, assert_fn) \
{ \
if (UseCompressedOops) { \
InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
start_p, count, \
do_oop, assert_fn) \
} else { \
InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
start_p, count, \
do_oop, assert_fn) \
} \
}
#define InstanceKlass_BOUNDED_OOP_ITERATE(start_p, count, low, high, \
do_oop, assert_fn) \
{ \
if (UseCompressedOops) { \
InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
start_p, count, \
low, high, \
do_oop, assert_fn) \
} else { \
InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
start_p, count, \
low, high, \
do_oop, assert_fn) \
} \
}
#define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn) \
{ \
/* Compute oopmap block range. The common case \
is nonstatic_oop_map_size == 1. */ \
OopMapBlock* map = start_of_nonstatic_oop_maps(); \
OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
if (UseCompressedOops) { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
do_oop, assert_fn) \
++map; \
} \
} else { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_OOP_ITERATE(oop, \
obj->obj_field_addr<oop>(map->offset()), map->count(), \
do_oop, assert_fn) \
++map; \
} \
} \
}
#define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn) \
{ \
OopMapBlock* const start_map = start_of_nonstatic_oop_maps(); \
OopMapBlock* map = start_map + nonstatic_oop_map_count(); \
if (UseCompressedOops) { \
while (start_map < map) { \
--map; \
InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop, \
obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
do_oop, assert_fn) \
} \
} else { \
while (start_map < map) { \
--map; \
InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop, \
obj->obj_field_addr<oop>(map->offset()), map->count(), \
do_oop, assert_fn) \
} \
} \
}
#define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop, \
assert_fn) \
{ \
/* Compute oopmap block range. The common case is \
nonstatic_oop_map_size == 1, so we accept the \
usually non-existent extra overhead of examining \
all the maps. */ \
OopMapBlock* map = start_of_nonstatic_oop_maps(); \
OopMapBlock* const end_map = map + nonstatic_oop_map_count(); \
if (UseCompressedOops) { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
obj->obj_field_addr<narrowOop>(map->offset()), map->count(), \
low, high, \
do_oop, assert_fn) \
++map; \
} \
} else { \
while (map < end_map) { \
InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop, \
obj->obj_field_addr<oop>(map->offset()), map->count(), \
low, high, \
do_oop, assert_fn) \
++map; \
} \
} \
}
void instanceKlass::follow_static_fields() {
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
MarkSweep::mark_and_push(p), \
assert_is_in_closed_subset)
}
#ifndef SERIALGC
void instanceKlass::follow_static_fields(ParCompactionManager* cm) {
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
PSParallelCompact::mark_and_push(cm, p), \
assert_is_in)
}
#endif // SERIALGC
void instanceKlass::adjust_static_fields() {
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
MarkSweep::adjust_pointer(p), \
assert_nothing)
}
#ifndef SERIALGC
void instanceKlass::update_static_fields() {
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
PSParallelCompact::adjust_pointer(p), \
assert_nothing)
}
void instanceKlass::update_static_fields(HeapWord* beg_addr, HeapWord* end_addr) {
InstanceKlass_BOUNDED_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
beg_addr, end_addr, \
PSParallelCompact::adjust_pointer(p), \
assert_nothing )
}
#endif // SERIALGC
void instanceKlass::oop_follow_contents(oop obj) {
assert(obj != NULL, "can't follow the content of NULL object");
obj->follow_header();
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
MarkSweep::mark_and_push(p), \
assert_is_in_closed_subset)
}
#ifndef SERIALGC
void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
oop obj) {
assert(obj != NULL, "can't follow the content of NULL object");
obj->follow_header(cm);
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
PSParallelCompact::mark_and_push(cm, p), \
assert_is_in)
}
#endif // SERIALGC
// closure's do_header() method dicates whether the given closure should be
// applied to the klass ptr in the object header.
#define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
\
int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
/* header */ \
if (closure->do_header()) { \
obj->oop_iterate_header(closure); \
} \
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
SpecializationStats:: \
record_do_oop_call##nv_suffix(SpecializationStats::ik); \
(closure)->do_oop##nv_suffix(p), \
assert_is_in_closed_subset) \
return size_helper(); \
}
#ifndef SERIALGC
#define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
\
int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj, \
OopClosureType* closure) { \
SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
/* header */ \
if (closure->do_header()) { \
obj->oop_iterate_header(closure); \
} \
/* instance variables */ \
InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
obj, \
SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
(closure)->do_oop##nv_suffix(p), \
assert_is_in_closed_subset) \
return size_helper(); \
}
#endif // !SERIALGC
#define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
\
int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj, \
OopClosureType* closure, \
MemRegion mr) { \
SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
if (closure->do_header()) { \
obj->oop_iterate_header(closure, mr); \
} \
InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
obj, mr.start(), mr.end(), \
(closure)->do_oop##nv_suffix(p), \
assert_is_in_closed_subset) \
return size_helper(); \
}
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
#ifndef SERIALGC
ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
#endif // !SERIALGC
void instanceKlass::iterate_static_fields(OopClosure* closure) {
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
closure->do_oop(p), \
assert_is_in_reserved)
}
void instanceKlass::iterate_static_fields(OopClosure* closure,
MemRegion mr) {
InstanceKlass_BOUNDED_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
mr.start(), mr.end(), \
(closure)->do_oop_v(p), \
assert_is_in_closed_subset)
}
int instanceKlass::oop_adjust_pointers(oop obj) {
int size = size_helper();
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
MarkSweep::adjust_pointer(p), \
assert_is_in)
obj->adjust_header();
return size;
}
#ifndef SERIALGC
void instanceKlass::oop_copy_contents(PSPromotionManager* pm, oop obj) {
assert(!pm->depth_first(), "invariant");
InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
obj, \
if (PSScavenge::should_scavenge(p)) { \
pm->claim_or_forward_breadth(p); \
}, \
assert_nothing )
}
void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
assert(pm->depth_first(), "invariant");
InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
obj, \
if (PSScavenge::should_scavenge(p)) { \
pm->claim_or_forward_depth(p); \
}, \
assert_nothing )
}
int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
InstanceKlass_OOP_MAP_ITERATE( \
obj, \
PSParallelCompact::adjust_pointer(p), \
assert_nothing)
return size_helper();
}
int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
HeapWord* beg_addr, HeapWord* end_addr) {
InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
obj, beg_addr, end_addr, \
PSParallelCompact::adjust_pointer(p), \
assert_nothing)
return size_helper();
}
void instanceKlass::copy_static_fields(PSPromotionManager* pm) {
assert(!pm->depth_first(), "invariant");
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
if (PSScavenge::should_scavenge(p)) { \
pm->claim_or_forward_breadth(p); \
}, \
assert_nothing )
}
void instanceKlass::push_static_fields(PSPromotionManager* pm) {
assert(pm->depth_first(), "invariant");
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
if (PSScavenge::should_scavenge(p)) { \
pm->claim_or_forward_depth(p); \
}, \
assert_nothing )
}
void instanceKlass::copy_static_fields(ParCompactionManager* cm) {
InstanceKlass_OOP_ITERATE( \
start_of_static_fields(), static_oop_field_size(), \
PSParallelCompact::adjust_pointer(p), \
assert_is_in)
}
#endif // SERIALGC
// This klass is alive but the implementor link is not followed/updated.
// Subklass and sibling links are handled by Klass::follow_weak_klass_links
void instanceKlass::follow_weak_klass_links(
BoolObjectClosure* is_alive, OopClosure* keep_alive) {
assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
if (ClassUnloading) {
for (int i = 0; i < implementors_limit; i++) {
klassOop impl = _implementors[i];
if (impl == NULL) break; // no more in the list
if (!is_alive->do_object_b(impl)) {
// remove this guy from the list by overwriting him with the tail
int lasti = --_nof_implementors;
assert(lasti >= i && lasti < implementors_limit, "just checking");
_implementors[i] = _implementors[lasti];
_implementors[lasti] = NULL;
--i; // rerun the loop at this index
}
}
} else {
for (int i = 0; i < implementors_limit; i++) {
keep_alive->do_oop(&adr_implementors()[i]);
}
}
Klass::follow_weak_klass_links(is_alive, keep_alive);
}
void instanceKlass::remove_unshareable_info() {
Klass::remove_unshareable_info();
init_implementor();
}
static void clear_all_breakpoints(methodOop m) {
m->clear_all_breakpoints();
}
void instanceKlass::release_C_heap_structures() {
// Deallocate oop map cache
if (_oop_map_cache != NULL) {
delete _oop_map_cache;
_oop_map_cache = NULL;
}
// Deallocate JNI identifiers for jfieldIDs
JNIid::deallocate(jni_ids());
set_jni_ids(NULL);
jmethodID* jmeths = methods_jmethod_ids_acquire();
if (jmeths != (jmethodID*)NULL) {
release_set_methods_jmethod_ids(NULL);
FreeHeap(jmeths);
}
int* indices = methods_cached_itable_indices_acquire();
if (indices != (int*)NULL) {
release_set_methods_cached_itable_indices(NULL);
FreeHeap(indices);
}
// release dependencies
nmethodBucket* b = _dependencies;
_dependencies = NULL;
while (b != NULL) {
nmethodBucket* next = b->next();
delete b;
b = next;
}
// Deallocate breakpoint records
if (breakpoints() != 0x0) {
methods_do(clear_all_breakpoints);
assert(breakpoints() == 0x0, "should have cleared breakpoints");
}
// deallocate information about previous versions
if (_previous_versions != NULL) {
for (int i = _previous_versions->length() - 1; i >= 0; i--) {
PreviousVersionNode * pv_node = _previous_versions->at(i);
delete pv_node;
}
delete _previous_versions;
_previous_versions = NULL;
}
// deallocate the cached class file
if (_cached_class_file_bytes != NULL) {
os::free(_cached_class_file_bytes);
_cached_class_file_bytes = NULL;
_cached_class_file_len = 0;
}
}
const char* instanceKlass::signature_name() const {
const char* src = (const char*) (name()->as_C_string());
const int src_length = (int)strlen(src);
char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
int src_index = 0;
int dest_index = 0;
dest[dest_index++] = 'L';
while (src_index < src_length) {
dest[dest_index++] = src[src_index++];
}
dest[dest_index++] = ';';
dest[dest_index] = '\0';
return dest;
}
// different verisons of is_same_class_package
bool instanceKlass::is_same_class_package(klassOop class2) {
klassOop class1 = as_klassOop();
oop classloader1 = instanceKlass::cast(class1)->class_loader();
symbolOop classname1 = Klass::cast(class1)->name();
if (Klass::cast(class2)->oop_is_objArray()) {
class2 = objArrayKlass::cast(class2)->bottom_klass();
}
oop classloader2;
if (Klass::cast(class2)->oop_is_instance()) {
classloader2 = instanceKlass::cast(class2)->class_loader();
} else {
assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
classloader2 = NULL;
}
symbolOop classname2 = Klass::cast(class2)->name();
return instanceKlass::is_same_class_package(classloader1, classname1,
classloader2, classname2);
}
bool instanceKlass::is_same_class_package(oop classloader2, symbolOop classname2) {
klassOop class1 = as_klassOop();
oop classloader1 = instanceKlass::cast(class1)->class_loader();
symbolOop classname1 = Klass::cast(class1)->name();
return instanceKlass::is_same_class_package(classloader1, classname1,
classloader2, classname2);
}
// return true if two classes are in the same package, classloader
// and classname information is enough to determine a class's package
bool instanceKlass::is_same_class_package(oop class_loader1, symbolOop class_name1,
oop class_loader2, symbolOop class_name2) {
if (class_loader1 != class_loader2) {
return false;
} else if (class_name1 == class_name2) {
return true; // skip painful bytewise comparison
} else {
ResourceMark rm;
// The symbolOop's are in UTF8 encoding. Since we only need to check explicitly
// for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
// Otherwise, we just compare jbyte values between the strings.
jbyte *name1 = class_name1->base();
jbyte *name2 = class_name2->base();
jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
// One of the two doesn't have a package. Only return true
// if the other one also doesn't have a package.
return last_slash1 == last_slash2;
} else {
// Skip over '['s
if (*name1 == '[') {
do {
name1++;
} while (*name1 == '[');
if (*name1 != 'L') {
// Something is terribly wrong. Shouldn't be here.
return false;
}
}
if (*name2 == '[') {
do {
name2++;
} while (*name2 == '[');
if (*name2 != 'L') {
// Something is terribly wrong. Shouldn't be here.
return false;
}
}
// Check that package part is identical
int length1 = last_slash1 - name1;
int length2 = last_slash2 - name2;
return UTF8::equal(name1, length1, name2, length2);
}
}
}
// Returns true iff super_method can be overridden by a method in targetclassname
// See JSL 3rd edition 8.4.6.1
// Assumes name-signature match
// "this" is instanceKlass of super_method which must exist
// note that the instanceKlass of the method in the targetclassname has not always been created yet
bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, symbolHandle targetclassname, TRAPS) {
// Private methods can not be overridden
if (super_method->is_private()) {
return false;
}
// If super method is accessible, then override
if ((super_method->is_protected()) ||
(super_method->is_public())) {
return true;
}
// Package-private methods are not inherited outside of package
assert(super_method->is_package_private(), "must be package private");
return(is_same_class_package(targetclassloader(), targetclassname()));
}
/* defined for now in jvm.cpp, for historical reasons *--
klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
symbolOop& simple_name_result, TRAPS) {
...
}
*/
// tell if two classes have the same enclosing class (at package level)
bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
klassOop class2_oop, TRAPS) {
if (class2_oop == class1->as_klassOop()) return true;
if (!Klass::cast(class2_oop)->oop_is_instance()) return false;
instanceKlassHandle class2(THREAD, class2_oop);
// must be in same package before we try anything else
if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
return false;
// As long as there is an outer1.getEnclosingClass,
// shift the search outward.
instanceKlassHandle outer1 = class1;
for (;;) {
// As we walk along, look for equalities between outer1 and class2.
// Eventually, the walks will terminate as outer1 stops
// at the top-level class around the original class.
bool ignore_inner_is_member;
klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
CHECK_false);
if (next == NULL) break;
if (next == class2()) return true;
outer1 = instanceKlassHandle(THREAD, next);
}
// Now do the same for class2.
instanceKlassHandle outer2 = class2;
for (;;) {
bool ignore_inner_is_member;
klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
CHECK_false);
if (next == NULL) break;
// Might as well check the new outer against all available values.
if (next == class1()) return true;
if (next == outer1()) return true;
outer2 = instanceKlassHandle(THREAD, next);
}
// If by this point we have not found an equality between the
// two classes, we know they are in separate package members.
return false;
}
jint instanceKlass::compute_modifier_flags(TRAPS) const {
klassOop k = as_klassOop();
jint access = access_flags().as_int();
// But check if it happens to be member class.
typeArrayOop inner_class_list = inner_classes();
int length = (inner_class_list == NULL) ? 0 : inner_class_list->length();
assert (length % instanceKlass::inner_class_next_offset == 0, "just checking");
if (length > 0) {
typeArrayHandle inner_class_list_h(THREAD, inner_class_list);
instanceKlassHandle ik(THREAD, k);
for (int i = 0; i < length; i += instanceKlass::inner_class_next_offset) {
int ioff = inner_class_list_h->ushort_at(
i + instanceKlass::inner_class_inner_class_info_offset);
// Inner class attribute can be zero, skip it.
// Strange but true: JVM spec. allows null inner class refs.
if (ioff == 0) continue;
// only look at classes that are already loaded
// since we are looking for the flags for our self.
symbolOop inner_name = ik->constants()->klass_name_at(ioff);
if ((ik->name() == inner_name)) {
// This is really a member class.
access = inner_class_list_h->ushort_at(i + instanceKlass::inner_class_access_flags_offset);
break;
}
}
}
// Remember to strip ACC_SUPER bit
return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
}
jint instanceKlass::jvmti_class_status() const {
jint result = 0;
if (is_linked()) {
result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
}
if (is_initialized()) {
assert(is_linked(), "Class status is not consistent");
result |= JVMTI_CLASS_STATUS_INITIALIZED;
}
if (is_in_error_state()) {
result |= JVMTI_CLASS_STATUS_ERROR;
}
return result;
}
methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
int method_table_offset_in_words = ioe->offset()/wordSize;
int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
/ itableOffsetEntry::size();
for (int cnt = 0 ; ; cnt ++, ioe ++) {
// If the interface isn't implemented by the receiver class,
// the VM should throw IncompatibleClassChangeError.
if (cnt >= nof_interfaces) {
THROW_OOP_0(vmSymbols::java_lang_IncompatibleClassChangeError());
}
klassOop ik = ioe->interface_klass();
if (ik == holder) break;
}
itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
methodOop m = ime[index].method();
if (m == NULL) {
THROW_OOP_0(vmSymbols::java_lang_AbstractMethodError());
}
return m;
}
// On-stack replacement stuff
void instanceKlass::add_osr_nmethod(nmethod* n) {
// only one compilation can be active
NEEDS_CLEANUP
// This is a short non-blocking critical region, so the no safepoint check is ok.
OsrList_lock->lock_without_safepoint_check();
assert(n->is_osr_method(), "wrong kind of nmethod");
n->set_osr_link(osr_nmethods_head());
set_osr_nmethods_head(n);
// Remember to unlock again
OsrList_lock->unlock();
}
void instanceKlass::remove_osr_nmethod(nmethod* n) {
// This is a short non-blocking critical region, so the no safepoint check is ok.
OsrList_lock->lock_without_safepoint_check();
assert(n->is_osr_method(), "wrong kind of nmethod");
nmethod* last = NULL;
nmethod* cur = osr_nmethods_head();
// Search for match
while(cur != NULL && cur != n) {
last = cur;
cur = cur->osr_link();
}
if (cur == n) {
if (last == NULL) {
// Remove first element
set_osr_nmethods_head(osr_nmethods_head()->osr_link());
} else {
last->set_osr_link(cur->osr_link());
}
}
n->set_osr_link(NULL);
// Remember to unlock again
OsrList_lock->unlock();
}
nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci) const {
// This is a short non-blocking critical region, so the no safepoint check is ok.
OsrList_lock->lock_without_safepoint_check();
nmethod* osr = osr_nmethods_head();
while (osr != NULL) {
assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
if (osr->method() == m &&
(bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
// Found a match - return it.
OsrList_lock->unlock();
return osr;
}
osr = osr->osr_link();
}
OsrList_lock->unlock();
return NULL;
}
// -----------------------------------------------------------------------------------------------------
#ifndef PRODUCT
// Printing
#define BULLET " - "
void FieldPrinter::do_field(fieldDescriptor* fd) {
_st->print(BULLET);
if (fd->is_static() || (_obj == NULL)) {
fd->print_on(_st);
_st->cr();
} else {
fd->print_on_for(_st, _obj);
_st->cr();
}
}
void instanceKlass::oop_print_on(oop obj, outputStream* st) {
Klass::oop_print_on(obj, st);
if (as_klassOop() == SystemDictionary::String_klass()) {
typeArrayOop value = java_lang_String::value(obj);
juint offset = java_lang_String::offset(obj);
juint length = java_lang_String::length(obj);
if (value != NULL &&
value->is_typeArray() &&
offset <= (juint) value->length() &&
offset + length <= (juint) value->length()) {
st->print(BULLET"string: ");
Handle h_obj(obj);
java_lang_String::print(h_obj, st);
st->cr();
if (!WizardMode) return; // that is enough
}
}
st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
FieldPrinter print_nonstatic_field(st, obj);
do_nonstatic_fields(&print_nonstatic_field);
if (as_klassOop() == SystemDictionary::Class_klass()) {
st->print(BULLET"signature: ");
java_lang_Class::print_signature(obj, st);
st->cr();
klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
st->print(BULLET"fake entry for mirror: ");
mirrored_klass->print_value_on(st);
st->cr();
st->print(BULLET"fake entry resolved_constructor: ");
methodOop ctor = java_lang_Class::resolved_constructor(obj);
ctor->print_value_on(st);
klassOop array_klass = java_lang_Class::array_klass(obj);
st->cr();
st->print(BULLET"fake entry for array: ");
array_klass->print_value_on(st);
st->cr();
} else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
st->print(BULLET"signature: ");
java_dyn_MethodType::print_signature(obj, st);
st->cr();
}
}
#endif //PRODUCT
void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
st->print("a ");
name()->print_value_on(st);
obj->print_address_on(st);
if (as_klassOop() == SystemDictionary::String_klass()
&& java_lang_String::value(obj) != NULL) {
ResourceMark rm;
int len = java_lang_String::length(obj);
int plen = (len < 24 ? len : 12);
char* str = java_lang_String::as_utf8_string(obj, 0, plen);
st->print(" = \"%s\"", str);
if (len > plen)
st->print("...[%d]", len);
} else if (as_klassOop() == SystemDictionary::Class_klass()) {
klassOop k = java_lang_Class::as_klassOop(obj);
st->print(" = ");
if (k != NULL) {
k->print_value_on(st);
} else {
const char* tname = type2name(java_lang_Class::primitive_type(obj));
st->print("%s", tname ? tname : "type?");
}
} else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
st->print(" = ");
java_dyn_MethodType::print_signature(obj, st);
} else if (java_lang_boxing_object::is_instance(obj)) {
st->print(" = ");
java_lang_boxing_object::print(obj, st);
}
}
const char* instanceKlass::internal_name() const {
return external_name();
}
// Verification
class VerifyFieldClosure: public OopClosure {
protected:
template <class T> void do_oop_work(T* p) {
guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
oop obj = oopDesc::load_decode_heap_oop(p);
if (!obj->is_oop_or_null()) {
tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
Universe::print();
guarantee(false, "boom");
}
}
public:
virtual void do_oop(oop* p) { VerifyFieldClosure::do_oop_work(p); }
virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
};
void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
Klass::oop_verify_on(obj, st);
VerifyFieldClosure blk;
oop_oop_iterate(obj, &blk);
}
#ifndef PRODUCT
void instanceKlass::verify_class_klass_nonstatic_oop_maps(klassOop k) {
// This verification code is disabled. JDK_Version::is_gte_jdk14x_version()
// cannot be called since this function is called before the VM is
// able to determine what JDK version is running with.
// The check below always is false since 1.4.
return;
// This verification code temporarily disabled for the 1.4
// reflection implementation since java.lang.Class now has
// Java-level instance fields. Should rewrite this to handle this
// case.
if (!(JDK_Version::is_gte_jdk14x_version() && UseNewReflection)) {
// Verify that java.lang.Class instances have a fake oop field added.
instanceKlass* ik = instanceKlass::cast(k);
// Check that we have the right class
static bool first_time = true;
guarantee(k == SystemDictionary::Class_klass() && first_time, "Invalid verify of maps");
first_time = false;
const int extra = java_lang_Class::number_of_fake_oop_fields;
guarantee(ik->nonstatic_field_size() == extra, "just checking");
guarantee(ik->nonstatic_oop_map_count() == 1, "just checking");
guarantee(ik->size_helper() == align_object_size(instanceOopDesc::header_size() + extra), "just checking");
// Check that the map is (2,extra)
int offset = java_lang_Class::klass_offset;
OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
guarantee(map->offset() == offset && map->count() == (unsigned int) extra,
"sanity");
}
}
#endif // ndef PRODUCT
// JNIid class for jfieldIDs only
// Note to reviewers:
// These JNI functions are just moved over to column 1 and not changed
// in the compressed oops workspace.
JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
_holder = holder;
_offset = offset;
_next = next;
debug_only(_is_static_field_id = false;)
}
JNIid* JNIid::find(int offset) {
JNIid* current = this;
while (current != NULL) {
if (current->offset() == offset) return current;
current = current->next();
}
return NULL;
}
void JNIid::oops_do(OopClosure* f) {
for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
f->do_oop(cur->holder_addr());
}
}
void JNIid::deallocate(JNIid* current) {
while (current != NULL) {
JNIid* next = current->next();
delete current;
current = next;
}
}
void JNIid::verify(klassOop holder) {
int first_field_offset = instanceKlass::cast(holder)->offset_of_static_fields();
int end_field_offset;
end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
JNIid* current = this;
while (current != NULL) {
guarantee(current->holder() == holder, "Invalid klass in JNIid");
#ifdef ASSERT
int o = current->offset();
if (current->is_static_field_id()) {
guarantee(o >= first_field_offset && o < end_field_offset, "Invalid static field offset in JNIid");
}
#endif
current = current->next();
}
}
#ifdef ASSERT
void instanceKlass::set_init_state(ClassState state) {
bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
: (_init_state < state);
assert(good_state || state == allocated, "illegal state transition");
_init_state = state;
}
#endif
// RedefineClasses() support for previous versions:
// Add an information node that contains weak references to the
// interesting parts of the previous version of the_class.
// This is also where we clean out any unused weak references.
// Note that while we delete nodes from the _previous_versions
// array, we never delete the array itself until the klass is
// unloaded. The has_been_redefined() query depends on that fact.
//
void instanceKlass::add_previous_version(instanceKlassHandle ikh,
BitMap* emcp_methods, int emcp_method_count) {
assert(Thread::current()->is_VM_thread(),
"only VMThread can add previous versions");
if (_previous_versions == NULL) {
// This is the first previous version so make some space.
// Start with 2 elements under the assumption that the class
// won't be redefined much.
_previous_versions = new (ResourceObj::C_HEAP)
GrowableArray<PreviousVersionNode *>(2, true);
}
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
ikh->external_name(), _previous_versions->length(), emcp_method_count));
constantPoolHandle cp_h(ikh->constants());
jobject cp_ref;
if (cp_h->is_shared()) {
// a shared ConstantPool requires a regular reference; a weak
// reference would be collectible
cp_ref = JNIHandles::make_global(cp_h);
} else {
cp_ref = JNIHandles::make_weak_global(cp_h);
}
PreviousVersionNode * pv_node = NULL;
objArrayOop old_methods = ikh->methods();
if (emcp_method_count == 0) {
// non-shared ConstantPool gets a weak reference
pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
RC_TRACE(0x00000400,
("add: all methods are obsolete; flushing any EMCP weak refs"));
} else {
int local_count = 0;
GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP)
GrowableArray<jweak>(emcp_method_count, true);
for (int i = 0; i < old_methods->length(); i++) {
if (emcp_methods->at(i)) {
// this old method is EMCP so save a weak ref
methodOop old_method = (methodOop) old_methods->obj_at(i);
methodHandle old_method_h(old_method);
jweak method_ref = JNIHandles::make_weak_global(old_method_h);
method_refs->append(method_ref);
if (++local_count >= emcp_method_count) {
// no more EMCP methods so bail out now
break;
}
}
}
// non-shared ConstantPool gets a weak reference
pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
}
_previous_versions->append(pv_node);
// Using weak references allows the interesting parts of previous
// classes to be GC'ed when they are no longer needed. Since the
// caller is the VMThread and we are at a safepoint, this is a good
// time to clear out unused weak references.
RC_TRACE(0x00000400, ("add: previous version length=%d",
_previous_versions->length()));
// skip the last entry since we just added it
for (int i = _previous_versions->length() - 2; i >= 0; i--) {
// check the previous versions array for a GC'ed weak refs
pv_node = _previous_versions->at(i);
cp_ref = pv_node->prev_constant_pool();
assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
if (cp_ref == NULL) {
delete pv_node;
_previous_versions->remove_at(i);
// Since we are traversing the array backwards, we don't have to
// do anything special with the index.
continue; // robustness
}
constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
if (cp == NULL) {
// this entry has been GC'ed so remove it
delete pv_node;
_previous_versions->remove_at(i);
// Since we are traversing the array backwards, we don't have to
// do anything special with the index.
continue;
} else {
RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
}
GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
if (method_refs != NULL) {
RC_TRACE(0x00000400, ("add: previous methods length=%d",
method_refs->length()));
for (int j = method_refs->length() - 1; j >= 0; j--) {
jweak method_ref = method_refs->at(j);
assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
if (method_ref == NULL) {
method_refs->remove_at(j);
// Since we are traversing the array backwards, we don't have to
// do anything special with the index.
continue; // robustness
}
methodOop method = (methodOop)JNIHandles::resolve(method_ref);
if (method == NULL || emcp_method_count == 0) {
// This method entry has been GC'ed or the current
// RedefineClasses() call has made all methods obsolete
// so remove it.
JNIHandles::destroy_weak_global(method_ref);
method_refs->remove_at(j);
} else {
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00000400,
("add: %s(%s): previous method @%d in version @%d is alive",
method->name()->as_C_string(), method->signature()->as_C_string(),
j, i));
}
}
}
}
int obsolete_method_count = old_methods->length() - emcp_method_count;
if (emcp_method_count != 0 && obsolete_method_count != 0 &&
_previous_versions->length() > 1) {
// We have a mix of obsolete and EMCP methods. If there is more
// than the previous version that we just added, then we have to
// clear out any matching EMCP method entries the hard way.
int local_count = 0;
for (int i = 0; i < old_methods->length(); i++) {
if (!emcp_methods->at(i)) {
// only obsolete methods are interesting
methodOop old_method = (methodOop) old_methods->obj_at(i);
symbolOop m_name = old_method->name();
symbolOop m_signature = old_method->signature();
// skip the last entry since we just added it
for (int j = _previous_versions->length() - 2; j >= 0; j--) {
// check the previous versions array for a GC'ed weak refs
pv_node = _previous_versions->at(j);
cp_ref = pv_node->prev_constant_pool();
assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
if (cp_ref == NULL) {
delete pv_node;
_previous_versions->remove_at(j);
// Since we are traversing the array backwards, we don't have to
// do anything special with the index.
continue; // robustness
}
constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
if (cp == NULL) {
// this entry has been GC'ed so remove it
delete pv_node;
_previous_versions->remove_at(j);
// Since we are traversing the array backwards, we don't have to
// do anything special with the index.
continue;
}
GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
if (method_refs == NULL) {
// We have run into a PreviousVersion generation where
// all methods were made obsolete during that generation's
// RedefineClasses() operation. At the time of that
// operation, all EMCP methods were flushed so we don't
// have to go back any further.
//
// A NULL method_refs is different than an empty method_refs.
// We cannot infer any optimizations about older generations
// from an empty method_refs for the current generation.
break;
}
for (int k = method_refs->length() - 1; k >= 0; k--) {
jweak method_ref = method_refs->at(k);
assert(method_ref != NULL,
"weak method ref was unexpectedly cleared");
if (method_ref == NULL) {
method_refs->remove_at(k);
// Since we are traversing the array backwards, we don't
// have to do anything special with the index.
continue; // robustness
}
methodOop method = (methodOop)JNIHandles::resolve(method_ref);
if (method == NULL) {
// this method entry has been GC'ed so skip it
JNIHandles::destroy_weak_global(method_ref);
method_refs->remove_at(k);
continue;
}
if (method->name() == m_name &&
method->signature() == m_signature) {
// The current RedefineClasses() call has made all EMCP
// versions of this method obsolete so mark it as obsolete
// and remove the weak ref.
RC_TRACE(0x00000400,
("add: %s(%s): flush obsolete method @%d in version @%d",
m_name->as_C_string(), m_signature->as_C_string(), k, j));
method->set_is_obsolete();
JNIHandles::destroy_weak_global(method_ref);
method_refs->remove_at(k);
break;
}
}
// The previous loop may not find a matching EMCP method, but
// that doesn't mean that we can optimize and not go any
// further back in the PreviousVersion generations. The EMCP
// method for this generation could have already been GC'ed,
// but there still may be an older EMCP method that has not
// been GC'ed.
}
if (++local_count >= obsolete_method_count) {
// no more obsolete methods so bail out now
break;
}
}
}
}
} // end add_previous_version()
// Determine if instanceKlass has a previous version.
bool instanceKlass::has_previous_version() const {
if (_previous_versions == NULL) {
// no previous versions array so answer is easy
return false;
}
for (int i = _previous_versions->length() - 1; i >= 0; i--) {
// Check the previous versions array for an info node that hasn't
// been GC'ed
PreviousVersionNode * pv_node = _previous_versions->at(i);
jobject cp_ref = pv_node->prev_constant_pool();
assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
if (cp_ref == NULL) {
continue; // robustness
}
constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
if (cp != NULL) {
// we have at least one previous version
return true;
}
// We don't have to check the method refs. If the constant pool has
// been GC'ed then so have the methods.
}
// all of the underlying nodes' info has been GC'ed
return false;
} // end has_previous_version()
methodOop instanceKlass::method_with_idnum(int idnum) {
methodOop m = NULL;
if (idnum < methods()->length()) {
m = (methodOop) methods()->obj_at(idnum);
}
if (m == NULL || m->method_idnum() != idnum) {
for (int index = 0; index < methods()->length(); ++index) {
m = (methodOop) methods()->obj_at(index);
if (m->method_idnum() == idnum) {
return m;
}
}
}
return m;
}
// Set the annotation at 'idnum' to 'anno'.
// We don't want to create or extend the array if 'anno' is NULL, since that is the
// default value. However, if the array exists and is long enough, we must set NULL values.
void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
objArrayOop md = *md_p;
if (md != NULL && md->length() > idnum) {
md->obj_at_put(idnum, anno);
} else if (anno != NULL) {
// create the array
int length = MAX2(idnum+1, (int)_idnum_allocated_count);
md = oopFactory::new_system_objArray(length, Thread::current());
if (*md_p != NULL) {
// copy the existing entries
for (int index = 0; index < (*md_p)->length(); index++) {
md->obj_at_put(index, (*md_p)->obj_at(index));
}
}
set_annotations(md, md_p);
md->obj_at_put(idnum, anno);
} // if no array and idnum isn't included there is nothing to do
}
// Construct a PreviousVersionNode entry for the array hung off
// the instanceKlass.
PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
_prev_constant_pool = prev_constant_pool;
_prev_cp_is_weak = prev_cp_is_weak;
_prev_EMCP_methods = prev_EMCP_methods;
}
// Destroy a PreviousVersionNode
PreviousVersionNode::~PreviousVersionNode() {
if (_prev_constant_pool != NULL) {
if (_prev_cp_is_weak) {
JNIHandles::destroy_weak_global(_prev_constant_pool);
} else {
JNIHandles::destroy_global(_prev_constant_pool);
}
}
if (_prev_EMCP_methods != NULL) {
for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
jweak method_ref = _prev_EMCP_methods->at(i);
if (method_ref != NULL) {
JNIHandles::destroy_weak_global(method_ref);
}
}
delete _prev_EMCP_methods;
}
}
// Construct a PreviousVersionInfo entry
PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
_prev_constant_pool_handle = constantPoolHandle(); // NULL handle
_prev_EMCP_method_handles = NULL;
jobject cp_ref = pv_node->prev_constant_pool();
assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
if (cp_ref == NULL) {
return; // robustness
}
constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
if (cp == NULL) {
// Weak reference has been GC'ed. Since the constant pool has been
// GC'ed, the methods have also been GC'ed.
return;
}
// make the constantPoolOop safe to return
_prev_constant_pool_handle = constantPoolHandle(cp);
GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
if (method_refs == NULL) {
// the instanceKlass did not have any EMCP methods
return;
}
_prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
int n_methods = method_refs->length();
for (int i = 0; i < n_methods; i++) {
jweak method_ref = method_refs->at(i);
assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
if (method_ref == NULL) {
continue; // robustness
}
methodOop method = (methodOop)JNIHandles::resolve(method_ref);
if (method == NULL) {
// this entry has been GC'ed so skip it
continue;
}
// make the methodOop safe to return
_prev_EMCP_method_handles->append(methodHandle(method));
}
}
// Destroy a PreviousVersionInfo
PreviousVersionInfo::~PreviousVersionInfo() {
// Since _prev_EMCP_method_handles is not C-heap allocated, we
// don't have to delete it.
}
// Construct a helper for walking the previous versions array
PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
_previous_versions = ik->previous_versions();
_current_index = 0;
// _hm needs no initialization
_current_p = NULL;
}
// Destroy a PreviousVersionWalker
PreviousVersionWalker::~PreviousVersionWalker() {
// Delete the current info just in case the caller didn't walk to
// the end of the previous versions list. No harm if _current_p is
// already NULL.
delete _current_p;
// When _hm is destroyed, all the Handles returned in
// PreviousVersionInfo objects will be destroyed.
// Also, after this destructor is finished it will be
// safe to delete the GrowableArray allocated in the
// PreviousVersionInfo objects.
}
// Return the interesting information for the next previous version
// of the klass. Returns NULL if there are no more previous versions.
PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
if (_previous_versions == NULL) {
// no previous versions so nothing to return
return NULL;
}
delete _current_p; // cleanup the previous info for the caller
_current_p = NULL; // reset to NULL so we don't delete same object twice
int length = _previous_versions->length();
while (_current_index < length) {
PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP)
PreviousVersionInfo(pv_node);
constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
if (cp_h.is_null()) {
delete pv_info;
// The underlying node's info has been GC'ed so try the next one.
// We don't have to check the methods. If the constant pool has
// GC'ed then so have the methods.
continue;
}
// Found a node with non GC'ed info so return it. The caller will
// need to delete pv_info when they are done with it.
_current_p = pv_info;
return pv_info;
}
// all of the underlying nodes' info has been GC'ed
return NULL;
} // end next_previous_version()