--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/klassVtable.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1613 @@
+/*
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "gc/shared/gcLocker.hpp"
+#include "logging/log.hpp"
+#include "logging/logStream.hpp"
+#include "memory/metaspaceShared.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/universe.inline.hpp"
+#include "oops/instanceKlass.hpp"
+#include "oops/klassVtable.hpp"
+#include "oops/method.hpp"
+#include "oops/objArrayOop.hpp"
+#include "oops/oop.inline.hpp"
+#include "prims/jvm.h"
+#include "runtime/arguments.hpp"
+#include "runtime/handles.inline.hpp"
+#include "utilities/copy.hpp"
+
+inline InstanceKlass* klassVtable::ik() const {
+ return InstanceKlass::cast(_klass);
+}
+
+bool klassVtable::is_preinitialized_vtable() {
+ return _klass->is_shared() && !MetaspaceShared::remapped_readwrite();
+}
+
+
+// this function computes the vtable size (including the size needed for miranda
+// methods) and the number of miranda methods in this class.
+// Note on Miranda methods: Let's say there is a class C that implements
+// interface I, and none of C's superclasses implements I.
+// Let's say there is an abstract method m in I that neither C
+// nor any of its super classes implement (i.e there is no method of any access,
+// with the same name and signature as m), then m is a Miranda method which is
+// entered as a public abstract method in C's vtable. From then on it should
+// treated as any other public method in C for method over-ride purposes.
+void klassVtable::compute_vtable_size_and_num_mirandas(
+ int* vtable_length_ret, int* num_new_mirandas,
+ GrowableArray<Method*>* all_mirandas, const Klass* super,
+ Array<Method*>* methods, AccessFlags class_flags, u2 major_version,
+ Handle classloader, Symbol* classname, Array<Klass*>* local_interfaces,
+ TRAPS) {
+ NoSafepointVerifier nsv;
+
+ // set up default result values
+ int vtable_length = 0;
+
+ // start off with super's vtable length
+ vtable_length = super == NULL ? 0 : super->vtable_length();
+
+ // go thru each method in the methods table to see if it needs a new entry
+ int len = methods->length();
+ for (int i = 0; i < len; i++) {
+ assert(methods->at(i)->is_method(), "must be a Method*");
+ methodHandle mh(THREAD, methods->at(i));
+
+ if (needs_new_vtable_entry(mh, super, classloader, classname, class_flags, major_version, THREAD)) {
+ vtable_length += vtableEntry::size(); // we need a new entry
+ }
+ }
+
+ GrowableArray<Method*> new_mirandas(20);
+ // compute the number of mirandas methods that must be added to the end
+ get_mirandas(&new_mirandas, all_mirandas, super, methods, NULL, local_interfaces);
+ *num_new_mirandas = new_mirandas.length();
+
+ // Interfaces do not need interface methods in their vtables
+ // This includes miranda methods and during later processing, default methods
+ if (!class_flags.is_interface()) {
+ vtable_length += *num_new_mirandas * vtableEntry::size();
+ }
+
+ if (Universe::is_bootstrapping() && vtable_length == 0) {
+ // array classes don't have their superclass set correctly during
+ // bootstrapping
+ vtable_length = Universe::base_vtable_size();
+ }
+
+ if (super == NULL && vtable_length != Universe::base_vtable_size()) {
+ if (Universe::is_bootstrapping()) {
+ // Someone is attempting to override java.lang.Object incorrectly on the
+ // bootclasspath. The JVM cannot recover from this error including throwing
+ // an exception
+ vm_exit_during_initialization("Incompatible definition of java.lang.Object");
+ } else {
+ // Someone is attempting to redefine java.lang.Object incorrectly. The
+ // only way this should happen is from
+ // SystemDictionary::resolve_from_stream(), which will detect this later
+ // and throw a security exception. So don't assert here to let
+ // the exception occur.
+ vtable_length = Universe::base_vtable_size();
+ }
+ }
+ assert(vtable_length % vtableEntry::size() == 0, "bad vtable length");
+ assert(vtable_length >= Universe::base_vtable_size(), "vtable too small");
+
+ *vtable_length_ret = vtable_length;
+}
+
+int klassVtable::index_of(Method* m, int len) const {
+ assert(m->has_vtable_index(), "do not ask this of non-vtable methods");
+ return m->vtable_index();
+}
+
+// Copy super class's vtable to the first part (prefix) of this class's vtable,
+// and return the number of entries copied. Expects that 'super' is the Java
+// super class (arrays can have "array" super classes that must be skipped).
+int klassVtable::initialize_from_super(Klass* super) {
+ if (super == NULL) {
+ return 0;
+ } else if (is_preinitialized_vtable()) {
+ // A shared class' vtable is preinitialized at dump time. No need to copy
+ // methods from super class for shared class, as that was already done
+ // during archiving time. However, if Jvmti has redefined a class,
+ // copy super class's vtable in case the super class has changed.
+ return super->vtable().length();
+ } else {
+ // copy methods from superKlass
+ klassVtable superVtable = super->vtable();
+ assert(superVtable.length() <= _length, "vtable too short");
+#ifdef ASSERT
+ superVtable.verify(tty, true);
+#endif
+ superVtable.copy_vtable_to(table());
+ if (log_develop_is_enabled(Trace, vtables)) {
+ ResourceMark rm;
+ log_develop_trace(vtables)("copy vtable from %s to %s size %d",
+ super->internal_name(), klass()->internal_name(),
+ _length);
+ }
+ return superVtable.length();
+ }
+}
+
+//
+// Revised lookup semantics introduced 1.3 (Kestrel beta)
+void klassVtable::initialize_vtable(bool checkconstraints, TRAPS) {
+
+ // Note: Arrays can have intermediate array supers. Use java_super to skip them.
+ Klass* super = _klass->java_super();
+ int nofNewEntries = 0;
+
+ bool is_shared = _klass->is_shared();
+
+ if (!_klass->is_array_klass()) {
+ ResourceMark rm(THREAD);
+ log_develop_debug(vtables)("Initializing: %s", _klass->name()->as_C_string());
+ }
+
+#ifdef ASSERT
+ oop* end_of_obj = (oop*)_klass + _klass->size();
+ oop* end_of_vtable = (oop*)&table()[_length];
+ assert(end_of_vtable <= end_of_obj, "vtable extends beyond end");
+#endif
+
+ if (Universe::is_bootstrapping()) {
+ assert(!is_shared, "sanity");
+ // just clear everything
+ for (int i = 0; i < _length; i++) table()[i].clear();
+ return;
+ }
+
+ int super_vtable_len = initialize_from_super(super);
+ if (_klass->is_array_klass()) {
+ assert(super_vtable_len == _length, "arrays shouldn't introduce new methods");
+ } else {
+ assert(_klass->is_instance_klass(), "must be InstanceKlass");
+
+ Array<Method*>* methods = ik()->methods();
+ int len = methods->length();
+ int initialized = super_vtable_len;
+
+ // Check each of this class's methods against super;
+ // if override, replace in copy of super vtable, otherwise append to end
+ for (int i = 0; i < len; i++) {
+ // update_inherited_vtable can stop for gc - ensure using handles
+ HandleMark hm(THREAD);
+ assert(methods->at(i)->is_method(), "must be a Method*");
+ methodHandle mh(THREAD, methods->at(i));
+
+ bool needs_new_entry = update_inherited_vtable(ik(), mh, super_vtable_len, -1, checkconstraints, CHECK);
+
+ if (needs_new_entry) {
+ put_method_at(mh(), initialized);
+ mh()->set_vtable_index(initialized); // set primary vtable index
+ initialized++;
+ }
+ }
+
+ // update vtable with default_methods
+ Array<Method*>* default_methods = ik()->default_methods();
+ if (default_methods != NULL) {
+ len = default_methods->length();
+ if (len > 0) {
+ Array<int>* def_vtable_indices = NULL;
+ if ((def_vtable_indices = ik()->default_vtable_indices()) == NULL) {
+ assert(!is_shared, "shared class def_vtable_indices does not exist");
+ def_vtable_indices = ik()->create_new_default_vtable_indices(len, CHECK);
+ } else {
+ assert(def_vtable_indices->length() == len, "reinit vtable len?");
+ }
+ for (int i = 0; i < len; i++) {
+ HandleMark hm(THREAD);
+ assert(default_methods->at(i)->is_method(), "must be a Method*");
+ methodHandle mh(THREAD, default_methods->at(i));
+ assert(!mh->is_private(), "private interface method in the default method list");
+ bool needs_new_entry = update_inherited_vtable(ik(), mh, super_vtable_len, i, checkconstraints, CHECK);
+
+ // needs new entry
+ if (needs_new_entry) {
+ put_method_at(mh(), initialized);
+ if (is_preinitialized_vtable()) {
+ // At runtime initialize_vtable is rerun for a shared class
+ // (loaded by the non-boot loader) as part of link_class_impl().
+ // The dumptime vtable index should be the same as the runtime index.
+ assert(def_vtable_indices->at(i) == initialized,
+ "dump time vtable index is different from runtime index");
+ } else {
+ def_vtable_indices->at_put(i, initialized); //set vtable index
+ }
+ initialized++;
+ }
+ }
+ }
+ }
+
+ // add miranda methods; it will also return the updated initialized
+ // Interfaces do not need interface methods in their vtables
+ // This includes miranda methods and during later processing, default methods
+ if (!ik()->is_interface()) {
+ initialized = fill_in_mirandas(initialized);
+ }
+
+ // In class hierarchies where the accessibility is not increasing (i.e., going from private ->
+ // package_private -> public/protected), the vtable might actually be smaller than our initial
+ // calculation, for classfile versions for which we do not do transitive override
+ // calculations.
+ if (ik()->major_version() >= VTABLE_TRANSITIVE_OVERRIDE_VERSION) {
+ assert(initialized == _length, "vtable initialization failed");
+ } else {
+ assert(initialized <= _length, "vtable initialization failed");
+ for(;initialized < _length; initialized++) {
+ table()[initialized].clear();
+ }
+ }
+ NOT_PRODUCT(verify(tty, true));
+ }
+}
+
+// Called for cases where a method does not override its superclass' vtable entry
+// For bytecodes not produced by javac together it is possible that a method does not override
+// the superclass's method, but might indirectly override a super-super class's vtable entry
+// If none found, return a null superk, else return the superk of the method this does override
+// For public and protected methods: if they override a superclass, they will
+// also be overridden themselves appropriately.
+// Private methods do not override and are not overridden.
+// Package Private methods are trickier:
+// e.g. P1.A, pub m
+// P2.B extends A, package private m
+// P1.C extends B, public m
+// P1.C.m needs to override P1.A.m and can not override P2.B.m
+// Therefore: all package private methods need their own vtable entries for
+// them to be the root of an inheritance overriding decision
+// Package private methods may also override other vtable entries
+InstanceKlass* klassVtable::find_transitive_override(InstanceKlass* initialsuper, const methodHandle& target_method,
+ int vtable_index, Handle target_loader, Symbol* target_classname, Thread * THREAD) {
+ InstanceKlass* superk = initialsuper;
+ while (superk != NULL && superk->super() != NULL) {
+ InstanceKlass* supersuperklass = InstanceKlass::cast(superk->super());
+ klassVtable ssVtable = supersuperklass->vtable();
+ if (vtable_index < ssVtable.length()) {
+ Method* super_method = ssVtable.method_at(vtable_index);
+#ifndef PRODUCT
+ Symbol* name= target_method()->name();
+ Symbol* signature = target_method()->signature();
+ assert(super_method->name() == name && super_method->signature() == signature, "vtable entry name/sig mismatch");
+#endif
+ if (supersuperklass->is_override(super_method, target_loader, target_classname, THREAD)) {
+ if (log_develop_is_enabled(Trace, vtables)) {
+ ResourceMark rm(THREAD);
+ LogTarget(Trace, vtables) lt;
+ LogStream ls(lt);
+ char* sig = target_method()->name_and_sig_as_C_string();
+ ls.print("transitive overriding superclass %s with %s index %d, original flags: ",
+ supersuperklass->internal_name(),
+ sig, vtable_index);
+ super_method->print_linkage_flags(&ls);
+ ls.print("overriders flags: ");
+ target_method->print_linkage_flags(&ls);
+ ls.cr();
+ }
+
+ break; // return found superk
+ }
+ } else {
+ // super class has no vtable entry here, stop transitive search
+ superk = (InstanceKlass*)NULL;
+ break;
+ }
+ // if no override found yet, continue to search up
+ superk = superk->super() == NULL ? NULL : InstanceKlass::cast(superk->super());
+ }
+
+ return superk;
+}
+
+static void log_vtables(int i, bool overrides, const methodHandle& target_method,
+ Klass* target_klass, Method* super_method,
+ Thread* thread) {
+#ifndef PRODUCT
+ if (log_develop_is_enabled(Trace, vtables)) {
+ ResourceMark rm(thread);
+ LogTarget(Trace, vtables) lt;
+ LogStream ls(lt);
+ char* sig = target_method()->name_and_sig_as_C_string();
+ if (overrides) {
+ ls.print("overriding with %s index %d, original flags: ",
+ sig, i);
+ } else {
+ ls.print("NOT overriding with %s index %d, original flags: ",
+ sig, i);
+ }
+ super_method->print_linkage_flags(&ls);
+ ls.print("overriders flags: ");
+ target_method->print_linkage_flags(&ls);
+ ls.cr();
+ }
+#endif
+}
+
+// Update child's copy of super vtable for overrides
+// OR return true if a new vtable entry is required.
+// Only called for InstanceKlass's, i.e. not for arrays
+// If that changed, could not use _klass as handle for klass
+bool klassVtable::update_inherited_vtable(InstanceKlass* klass, const methodHandle& target_method,
+ int super_vtable_len, int default_index,
+ bool checkconstraints, TRAPS) {
+ ResourceMark rm;
+ bool allocate_new = true;
+ assert(klass->is_instance_klass(), "must be InstanceKlass");
+
+ Array<int>* def_vtable_indices = NULL;
+ bool is_default = false;
+
+ // default methods are non-private concrete methods in superinterfaces which are added
+ // to the vtable with their real method_holder.
+ // Since vtable and itable indices share the same storage, don't touch
+ // the default method's real vtable/itable index.
+ // default_vtable_indices stores the vtable value relative to this inheritor
+ if (default_index >= 0 ) {
+ is_default = true;
+ def_vtable_indices = klass->default_vtable_indices();
+ assert(!target_method()->is_private(), "private interface method flagged as default");
+ assert(def_vtable_indices != NULL, "def vtable alloc?");
+ assert(default_index <= def_vtable_indices->length(), "def vtable len?");
+ } else {
+ assert(klass == target_method()->method_holder(), "caller resp.");
+ // Initialize the method's vtable index to "nonvirtual".
+ // If we allocate a vtable entry, we will update it to a non-negative number.
+ target_method()->set_vtable_index(Method::nonvirtual_vtable_index);
+ }
+
+ // Static and <init> methods are never in
+ if (target_method()->is_static() || target_method()->name() == vmSymbols::object_initializer_name()) {
+ return false;
+ }
+
+ if (target_method->is_final_method(klass->access_flags())) {
+ // a final method never needs a new entry; final methods can be statically
+ // resolved and they have to be present in the vtable only if they override
+ // a super's method, in which case they re-use its entry
+ allocate_new = false;
+ } else if (klass->is_interface()) {
+ allocate_new = false; // see note below in needs_new_vtable_entry
+ // An interface never allocates new vtable slots, only inherits old ones.
+ // This method will either be assigned its own itable index later,
+ // or be assigned an inherited vtable index in the loop below.
+ // default methods inherited by classes store their vtable indices
+ // in the inheritor's default_vtable_indices.
+ // default methods inherited by interfaces may already have a
+ // valid itable index, if so, don't change it.
+ // Overpass methods in an interface will be assigned an itable index later
+ // by an inheriting class.
+ // Private interface methods have no itable index and are always invoked nonvirtually,
+ // so they retain their nonvirtual_vtable_index value, and therefore can_be_statically_bound()
+ // will return true.
+ if ((!is_default || !target_method()->has_itable_index()) && !target_method()->is_private()) {
+ target_method()->set_vtable_index(Method::pending_itable_index);
+ }
+ }
+
+ // we need a new entry if there is no superclass
+ Klass* super = klass->super();
+ if (super == NULL) {
+ return allocate_new;
+ }
+
+ // private methods in classes always have a new entry in the vtable
+ // specification interpretation since classic has
+ // private methods not overriding
+ // JDK8 adds private methods in interfaces which require invokespecial
+ if (target_method()->is_private()) {
+ return allocate_new;
+ }
+
+ // search through the vtable and update overridden entries
+ // Since check_signature_loaders acquires SystemDictionary_lock
+ // which can block for gc, once we are in this loop, use handles
+ // For classfiles built with >= jdk7, we now look for transitive overrides
+
+ Symbol* name = target_method()->name();
+ Symbol* signature = target_method()->signature();
+
+ Klass* target_klass = target_method()->method_holder();
+ if (target_klass == NULL) {
+ target_klass = _klass;
+ }
+
+ Handle target_loader(THREAD, target_klass->class_loader());
+
+ Symbol* target_classname = target_klass->name();
+ for(int i = 0; i < super_vtable_len; i++) {
+ Method* super_method;
+ if (is_preinitialized_vtable()) {
+ // If this is a shared class, the vtable is already in the final state (fully
+ // initialized). Need to look at the super's vtable.
+ klassVtable superVtable = super->vtable();
+ super_method = superVtable.method_at(i);
+ } else {
+ super_method = method_at(i);
+ }
+ // Check if method name matches
+ if (super_method->name() == name && super_method->signature() == signature) {
+
+ // get super_klass for method_holder for the found method
+ InstanceKlass* super_klass = super_method->method_holder();
+
+ // Whether the method is being overridden
+ bool overrides = false;
+
+ // private methods are also never overridden
+ if (!super_method->is_private() &&
+ (is_default
+ || ((super_klass->is_override(super_method, target_loader, target_classname, THREAD))
+ || ((klass->major_version() >= VTABLE_TRANSITIVE_OVERRIDE_VERSION)
+ && ((super_klass = find_transitive_override(super_klass,
+ target_method, i, target_loader,
+ target_classname, THREAD))
+ != (InstanceKlass*)NULL)))))
+ {
+ // Package private methods always need a new entry to root their own
+ // overriding. They may also override other methods.
+ if (!target_method()->is_package_private()) {
+ allocate_new = false;
+ }
+
+ if (checkconstraints) {
+ // Override vtable entry if passes loader constraint check
+ // if loader constraint checking requested
+ // No need to visit his super, since he and his super
+ // have already made any needed loader constraints.
+ // Since loader constraints are transitive, it is enough
+ // to link to the first super, and we get all the others.
+ Handle super_loader(THREAD, super_klass->class_loader());
+
+ if (target_loader() != super_loader()) {
+ ResourceMark rm(THREAD);
+ Symbol* failed_type_symbol =
+ SystemDictionary::check_signature_loaders(signature, target_loader,
+ super_loader, true,
+ CHECK_(false));
+ if (failed_type_symbol != NULL) {
+ const char* msg = "loader constraint violation: when resolving "
+ "overridden method \"%s\" the class loader (instance"
+ " of %s) of the current class, %s, and its superclass loader "
+ "(instance of %s), have different Class objects for the type "
+ "%s used in the signature";
+ char* sig = target_method()->name_and_sig_as_C_string();
+ const char* loader1 = SystemDictionary::loader_name(target_loader());
+ char* current = target_klass->name()->as_C_string();
+ const char* loader2 = SystemDictionary::loader_name(super_loader());
+ char* failed_type_name = failed_type_symbol->as_C_string();
+ size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
+ strlen(current) + strlen(loader2) + strlen(failed_type_name);
+ char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
+ jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
+ failed_type_name);
+ THROW_MSG_(vmSymbols::java_lang_LinkageError(), buf, false);
+ }
+ }
+ }
+
+ put_method_at(target_method(), i);
+ overrides = true;
+ if (!is_default) {
+ target_method()->set_vtable_index(i);
+ } else {
+ if (def_vtable_indices != NULL) {
+ if (is_preinitialized_vtable()) {
+ // At runtime initialize_vtable is rerun as part of link_class_impl()
+ // for a shared class loaded by the non-boot loader.
+ // The dumptime vtable index should be the same as the runtime index.
+ assert(def_vtable_indices->at(default_index) == i,
+ "dump time vtable index is different from runtime index");
+ } else {
+ def_vtable_indices->at_put(default_index, i);
+ }
+ }
+ assert(super_method->is_default_method() || super_method->is_overpass()
+ || super_method->is_abstract(), "default override error");
+ }
+ } else {
+ overrides = false;
+ }
+ log_vtables(i, overrides, target_method, target_klass, super_method, THREAD);
+ }
+ }
+ return allocate_new;
+}
+
+void klassVtable::put_method_at(Method* m, int index) {
+ if (is_preinitialized_vtable()) {
+ // At runtime initialize_vtable is rerun as part of link_class_impl()
+ // for shared class loaded by the non-boot loader to obtain the loader
+ // constraints based on the runtime classloaders' context. The dumptime
+ // method at the vtable index should be the same as the runtime method.
+ assert(table()[index].method() == m,
+ "archived method is different from the runtime method");
+ } else {
+ if (log_develop_is_enabled(Trace, vtables)) {
+ ResourceMark rm;
+ LogTarget(Trace, vtables) lt;
+ LogStream ls(lt);
+ const char* sig = (m != NULL) ? m->name_and_sig_as_C_string() : "<NULL>";
+ ls.print("adding %s at index %d, flags: ", sig, index);
+ if (m != NULL) {
+ m->print_linkage_flags(&ls);
+ }
+ ls.cr();
+ }
+ table()[index].set(m);
+ }
+}
+
+// Find out if a method "m" with superclass "super", loader "classloader" and
+// name "classname" needs a new vtable entry. Let P be a class package defined
+// by "classloader" and "classname".
+// NOTE: The logic used here is very similar to the one used for computing
+// the vtables indices for a method. We cannot directly use that function because,
+// we allocate the InstanceKlass at load time, and that requires that the
+// superclass has been loaded.
+// However, the vtable entries are filled in at link time, and therefore
+// the superclass' vtable may not yet have been filled in.
+bool klassVtable::needs_new_vtable_entry(const methodHandle& target_method,
+ const Klass* super,
+ Handle classloader,
+ Symbol* classname,
+ AccessFlags class_flags,
+ u2 major_version,
+ TRAPS) {
+ if (class_flags.is_interface()) {
+ // Interfaces do not use vtables, except for java.lang.Object methods,
+ // so there is no point to assigning
+ // a vtable index to any of their local methods. If we refrain from doing this,
+ // we can use Method::_vtable_index to hold the itable index
+ return false;
+ }
+
+ if (target_method->is_final_method(class_flags) ||
+ // a final method never needs a new entry; final methods can be statically
+ // resolved and they have to be present in the vtable only if they override
+ // a super's method, in which case they re-use its entry
+ (target_method()->is_static()) ||
+ // static methods don't need to be in vtable
+ (target_method()->name() == vmSymbols::object_initializer_name())
+ // <init> is never called dynamically-bound
+ ) {
+ return false;
+ }
+
+ // Concrete interface methods do not need new entries, they override
+ // abstract method entries using default inheritance rules
+ if (target_method()->method_holder() != NULL &&
+ target_method()->method_holder()->is_interface() &&
+ !target_method()->is_abstract()) {
+ assert(target_method()->is_default_method() || target_method()->is_private(),
+ "unexpected interface method type");
+ return false;
+ }
+
+ // we need a new entry if there is no superclass
+ if (super == NULL) {
+ return true;
+ }
+
+ // private methods in classes always have a new entry in the vtable.
+ // Specification interpretation since classic has private methods not overriding.
+ if (target_method()->is_private()) {
+ return true;
+ }
+
+ // Package private methods always need a new entry to root their own
+ // overriding. This allows transitive overriding to work.
+ if (target_method()->is_package_private()) {
+ return true;
+ }
+
+ // search through the super class hierarchy to see if we need
+ // a new entry
+ ResourceMark rm;
+ Symbol* name = target_method()->name();
+ Symbol* signature = target_method()->signature();
+ const Klass* k = super;
+ Method* super_method = NULL;
+ InstanceKlass *holder = NULL;
+ Method* recheck_method = NULL;
+ while (k != NULL) {
+ // lookup through the hierarchy for a method with matching name and sign.
+ super_method = InstanceKlass::cast(k)->lookup_method(name, signature);
+ if (super_method == NULL) {
+ break; // we still have to search for a matching miranda method
+ }
+ // get the class holding the matching method
+ // make sure you use that class for is_override
+ InstanceKlass* superk = super_method->method_holder();
+ // we want only instance method matches
+ // pretend private methods are not in the super vtable
+ // since we do override around them: e.g. a.m pub/b.m private/c.m pub,
+ // ignore private, c.m pub does override a.m pub
+ // For classes that were not javac'd together, we also do transitive overriding around
+ // methods that have less accessibility
+ if ((!super_method->is_static()) &&
+ (!super_method->is_private())) {
+ if (superk->is_override(super_method, classloader, classname, THREAD)) {
+ return false;
+ // else keep looking for transitive overrides
+ }
+ }
+
+ // Start with lookup result and continue to search up, for versions supporting transitive override
+ if (major_version >= VTABLE_TRANSITIVE_OVERRIDE_VERSION) {
+ k = superk->super(); // haven't found an override match yet; continue to look
+ } else {
+ break;
+ }
+ }
+
+ // if the target method is public or protected it may have a matching
+ // miranda method in the super, whose entry it should re-use.
+ // Actually, to handle cases that javac would not generate, we need
+ // this check for all access permissions.
+ const InstanceKlass *sk = InstanceKlass::cast(super);
+ if (sk->has_miranda_methods()) {
+ if (sk->lookup_method_in_all_interfaces(name, signature, Klass::find_defaults) != NULL) {
+ return false; // found a matching miranda; we do not need a new entry
+ }
+ }
+ return true; // found no match; we need a new entry
+}
+
+// Support for miranda methods
+
+// get the vtable index of a miranda method with matching "name" and "signature"
+int klassVtable::index_of_miranda(Symbol* name, Symbol* signature) {
+ // search from the bottom, might be faster
+ for (int i = (length() - 1); i >= 0; i--) {
+ Method* m = table()[i].method();
+ if (is_miranda_entry_at(i) &&
+ m->name() == name && m->signature() == signature) {
+ return i;
+ }
+ }
+ return Method::invalid_vtable_index;
+}
+
+// check if an entry at an index is miranda
+// requires that method m at entry be declared ("held") by an interface.
+bool klassVtable::is_miranda_entry_at(int i) {
+ Method* m = method_at(i);
+ Klass* method_holder = m->method_holder();
+ InstanceKlass *mhk = InstanceKlass::cast(method_holder);
+
+ // miranda methods are public abstract instance interface methods in a class's vtable
+ if (mhk->is_interface()) {
+ assert(m->is_public(), "should be public");
+ assert(ik()->implements_interface(method_holder) , "this class should implement the interface");
+ if (is_miranda(m, ik()->methods(), ik()->default_methods(), ik()->super())) {
+ return true;
+ }
+ }
+ return false;
+}
+
+// Check if a method is a miranda method, given a class's methods array,
+// its default_method table and its super class.
+// "Miranda" means an abstract non-private method that would not be
+// overridden for the local class.
+// A "miranda" method should only include non-private interface
+// instance methods, i.e. not private methods, not static methods,
+// not default methods (concrete interface methods), not overpass methods.
+// If a given class already has a local (including overpass) method, a
+// default method, or any of its superclasses has the same which would have
+// overridden an abstract method, then this is not a miranda method.
+//
+// Miranda methods are checked multiple times.
+// Pass 1: during class load/class file parsing: before vtable size calculation:
+// include superinterface abstract and default methods (non-private instance).
+// We include potential default methods to give them space in the vtable.
+// During the first run, the current instanceKlass has not yet been
+// created, the superclasses and superinterfaces do have instanceKlasses
+// but may not have vtables, the default_methods list is empty, no overpasses.
+// This is seen by default method creation.
+//
+// Pass 2: recalculated during vtable initialization: only include abstract methods.
+// The goal of pass 2 is to walk through the superinterfaces to see if any of
+// the superinterface methods (which were all abstract pre-default methods)
+// need to be added to the vtable.
+// With the addition of default methods, we have three new challenges:
+// overpasses, static interface methods and private interface methods.
+// Static and private interface methods do not get added to the vtable and
+// are not seen by the method resolution process, so we skip those.
+// Overpass methods are already in the vtable, so vtable lookup will
+// find them and we don't need to add a miranda method to the end of
+// the vtable. So we look for overpass methods and if they are found we
+// return false. Note that we inherit our superclasses vtable, so
+// the superclass' search also needs to use find_overpass so that if
+// one is found we return false.
+// False means - we don't need a miranda method added to the vtable.
+//
+// During the second run, default_methods is set up, so concrete methods from
+// superinterfaces with matching names/signatures to default_methods are already
+// in the default_methods list and do not need to be appended to the vtable
+// as mirandas. Abstract methods may already have been handled via
+// overpasses - either local or superclass overpasses, which may be
+// in the vtable already.
+//
+// Pass 3: They are also checked by link resolution and selection,
+// for invocation on a method (not interface method) reference that
+// resolves to a method with an interface as its method_holder.
+// Used as part of walking from the bottom of the vtable to find
+// the vtable index for the miranda method.
+//
+// Part of the Miranda Rights in the US mean that if you do not have
+// an attorney one will be appointed for you.
+bool klassVtable::is_miranda(Method* m, Array<Method*>* class_methods,
+ Array<Method*>* default_methods, const Klass* super) {
+ if (m->is_static() || m->is_private() || m->is_overpass()) {
+ return false;
+ }
+ Symbol* name = m->name();
+ Symbol* signature = m->signature();
+
+ // First look in local methods to see if already covered
+ if (InstanceKlass::find_local_method(class_methods, name, signature,
+ Klass::find_overpass, Klass::skip_static, Klass::skip_private) != NULL)
+ {
+ return false;
+ }
+
+ // Check local default methods
+ if ((default_methods != NULL) &&
+ (InstanceKlass::find_method(default_methods, name, signature) != NULL))
+ {
+ return false;
+ }
+
+ // Iterate on all superclasses, which should be InstanceKlasses.
+ // Note that we explicitly look for overpasses at each level.
+ // Overpasses may or may not exist for supers for pass 1,
+ // they should have been created for pass 2 and later.
+
+ for (const Klass* cursuper = super; cursuper != NULL; cursuper = cursuper->super())
+ {
+ if (InstanceKlass::cast(cursuper)->find_local_method(name, signature,
+ Klass::find_overpass, Klass::skip_static, Klass::skip_private) != NULL) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+// Scans current_interface_methods for miranda methods that do not
+// already appear in new_mirandas, or default methods, and are also not defined-and-non-private
+// in super (superclass). These mirandas are added to all_mirandas if it is
+// not null; in addition, those that are not duplicates of miranda methods
+// inherited by super from its interfaces are added to new_mirandas.
+// Thus, new_mirandas will be the set of mirandas that this class introduces,
+// all_mirandas will be the set of all mirandas applicable to this class
+// including all defined in superclasses.
+void klassVtable::add_new_mirandas_to_lists(
+ GrowableArray<Method*>* new_mirandas, GrowableArray<Method*>* all_mirandas,
+ Array<Method*>* current_interface_methods, Array<Method*>* class_methods,
+ Array<Method*>* default_methods, const Klass* super) {
+
+ // iterate thru the current interface's method to see if it a miranda
+ int num_methods = current_interface_methods->length();
+ for (int i = 0; i < num_methods; i++) {
+ Method* im = current_interface_methods->at(i);
+ bool is_duplicate = false;
+ int num_of_current_mirandas = new_mirandas->length();
+ // check for duplicate mirandas in different interfaces we implement
+ for (int j = 0; j < num_of_current_mirandas; j++) {
+ Method* miranda = new_mirandas->at(j);
+ if ((im->name() == miranda->name()) &&
+ (im->signature() == miranda->signature())) {
+ is_duplicate = true;
+ break;
+ }
+ }
+
+ if (!is_duplicate) { // we don't want duplicate miranda entries in the vtable
+ if (is_miranda(im, class_methods, default_methods, super)) { // is it a miranda at all?
+ const InstanceKlass *sk = InstanceKlass::cast(super);
+ // check if it is a duplicate of a super's miranda
+ if (sk->lookup_method_in_all_interfaces(im->name(), im->signature(), Klass::find_defaults) == NULL) {
+ new_mirandas->append(im);
+ }
+ if (all_mirandas != NULL) {
+ all_mirandas->append(im);
+ }
+ }
+ }
+ }
+}
+
+void klassVtable::get_mirandas(GrowableArray<Method*>* new_mirandas,
+ GrowableArray<Method*>* all_mirandas,
+ const Klass* super,
+ Array<Method*>* class_methods,
+ Array<Method*>* default_methods,
+ Array<Klass*>* local_interfaces) {
+ assert((new_mirandas->length() == 0) , "current mirandas must be 0");
+
+ // iterate thru the local interfaces looking for a miranda
+ int num_local_ifs = local_interfaces->length();
+ for (int i = 0; i < num_local_ifs; i++) {
+ InstanceKlass *ik = InstanceKlass::cast(local_interfaces->at(i));
+ add_new_mirandas_to_lists(new_mirandas, all_mirandas,
+ ik->methods(), class_methods,
+ default_methods, super);
+ // iterate thru each local's super interfaces
+ Array<Klass*>* super_ifs = ik->transitive_interfaces();
+ int num_super_ifs = super_ifs->length();
+ for (int j = 0; j < num_super_ifs; j++) {
+ InstanceKlass *sik = InstanceKlass::cast(super_ifs->at(j));
+ add_new_mirandas_to_lists(new_mirandas, all_mirandas,
+ sik->methods(), class_methods,
+ default_methods, super);
+ }
+ }
+}
+
+// Discover miranda methods ("miranda" = "interface abstract, no binding"),
+// and append them into the vtable starting at index initialized,
+// return the new value of initialized.
+// Miranda methods use vtable entries, but do not get assigned a vtable_index
+// The vtable_index is discovered by searching from the end of the vtable
+int klassVtable::fill_in_mirandas(int initialized) {
+ GrowableArray<Method*> mirandas(20);
+ get_mirandas(&mirandas, NULL, ik()->super(), ik()->methods(),
+ ik()->default_methods(), ik()->local_interfaces());
+ for (int i = 0; i < mirandas.length(); i++) {
+ if (log_develop_is_enabled(Trace, vtables)) {
+ Method* meth = mirandas.at(i);
+ ResourceMark rm(Thread::current());
+ LogTarget(Trace, vtables) lt;
+ LogStream ls(lt);
+ if (meth != NULL) {
+ char* sig = meth->name_and_sig_as_C_string();
+ ls.print("fill in mirandas with %s index %d, flags: ",
+ sig, initialized);
+ meth->print_linkage_flags(&ls);
+ ls.cr();
+ }
+ }
+ put_method_at(mirandas.at(i), initialized);
+ ++initialized;
+ }
+ return initialized;
+}
+
+// Copy this class's vtable to the vtable beginning at start.
+// Used to copy superclass vtable to prefix of subclass's vtable.
+void klassVtable::copy_vtable_to(vtableEntry* start) {
+ Copy::disjoint_words((HeapWord*)table(), (HeapWord*)start, _length * vtableEntry::size());
+}
+
+#if INCLUDE_JVMTI
+bool klassVtable::adjust_default_method(int vtable_index, Method* old_method, Method* new_method) {
+ // If old_method is default, find this vtable index in default_vtable_indices
+ // and replace that method in the _default_methods list
+ bool updated = false;
+
+ Array<Method*>* default_methods = ik()->default_methods();
+ if (default_methods != NULL) {
+ int len = default_methods->length();
+ for (int idx = 0; idx < len; idx++) {
+ if (vtable_index == ik()->default_vtable_indices()->at(idx)) {
+ if (default_methods->at(idx) == old_method) {
+ default_methods->at_put(idx, new_method);
+ updated = true;
+ }
+ break;
+ }
+ }
+ }
+ return updated;
+}
+
+// search the vtable for uses of either obsolete or EMCP methods
+void klassVtable::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
+ int prn_enabled = 0;
+ for (int index = 0; index < length(); index++) {
+ Method* old_method = unchecked_method_at(index);
+ if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
+ continue; // skip uninteresting entries
+ }
+ assert(!old_method->is_deleted(), "vtable methods may not be deleted");
+
+ Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
+
+ assert(new_method != NULL, "method_with_idnum() should not be NULL");
+ assert(old_method != new_method, "sanity check");
+
+ put_method_at(new_method, index);
+ // For default methods, need to update the _default_methods array
+ // which can only have one method entry for a given signature
+ bool updated_default = false;
+ if (old_method->is_default_method()) {
+ updated_default = adjust_default_method(index, old_method, new_method);
+ }
+
+ if (log_is_enabled(Info, redefine, class, update)) {
+ ResourceMark rm;
+ if (!(*trace_name_printed)) {
+ log_info(redefine, class, update)
+ ("adjust: klassname=%s for methods from name=%s",
+ _klass->external_name(), old_method->method_holder()->external_name());
+ *trace_name_printed = true;
+ }
+ log_debug(redefine, class, update, vtables)
+ ("vtable method update: %s(%s), updated default = %s",
+ new_method->name()->as_C_string(), new_method->signature()->as_C_string(), updated_default ? "true" : "false");
+ }
+ }
+}
+
+// a vtable should never contain old or obsolete methods
+bool klassVtable::check_no_old_or_obsolete_entries() {
+ for (int i = 0; i < length(); i++) {
+ Method* m = unchecked_method_at(i);
+ if (m != NULL &&
+ (NOT_PRODUCT(!m->is_valid() ||) m->is_old() || m->is_obsolete())) {
+ return false;
+ }
+ }
+ return true;
+}
+
+void klassVtable::dump_vtable() {
+ tty->print_cr("vtable dump --");
+ for (int i = 0; i < length(); i++) {
+ Method* m = unchecked_method_at(i);
+ if (m != NULL) {
+ tty->print(" (%5d) ", i);
+ m->access_flags().print_on(tty);
+ if (m->is_default_method()) {
+ tty->print("default ");
+ }
+ if (m->is_overpass()) {
+ tty->print("overpass");
+ }
+ tty->print(" -- ");
+ m->print_name(tty);
+ tty->cr();
+ }
+ }
+}
+#endif // INCLUDE_JVMTI
+
+// CDS/RedefineClasses support - clear vtables so they can be reinitialized
+void klassVtable::clear_vtable() {
+ for (int i = 0; i < _length; i++) table()[i].clear();
+}
+
+bool klassVtable::is_initialized() {
+ return _length == 0 || table()[0].method() != NULL;
+}
+
+//-----------------------------------------------------------------------------------------
+// Itable code
+
+// Initialize a itableMethodEntry
+void itableMethodEntry::initialize(Method* m) {
+ if (m == NULL) return;
+
+#ifdef ASSERT
+ if (MetaspaceShared::is_in_shared_space((void*)&_method) &&
+ !MetaspaceShared::remapped_readwrite()) {
+ // At runtime initialize_itable is rerun as part of link_class_impl()
+ // for a shared class loaded by the non-boot loader.
+ // The dumptime itable method entry should be the same as the runtime entry.
+ assert(_method == m, "sanity");
+ }
+#endif
+ _method = m;
+}
+
+klassItable::klassItable(InstanceKlass* klass) {
+ _klass = klass;
+
+ if (klass->itable_length() > 0) {
+ itableOffsetEntry* offset_entry = (itableOffsetEntry*)klass->start_of_itable();
+ if (offset_entry != NULL && offset_entry->interface_klass() != NULL) { // Check that itable is initialized
+ // First offset entry points to the first method_entry
+ intptr_t* method_entry = (intptr_t *)(((address)klass) + offset_entry->offset());
+ intptr_t* end = klass->end_of_itable();
+
+ _table_offset = (intptr_t*)offset_entry - (intptr_t*)klass;
+ _size_offset_table = (method_entry - ((intptr_t*)offset_entry)) / itableOffsetEntry::size();
+ _size_method_table = (end - method_entry) / itableMethodEntry::size();
+ assert(_table_offset >= 0 && _size_offset_table >= 0 && _size_method_table >= 0, "wrong computation");
+ return;
+ }
+ }
+
+ // The length of the itable was either zero, or it has not yet been initialized.
+ _table_offset = 0;
+ _size_offset_table = 0;
+ _size_method_table = 0;
+}
+
+static int initialize_count = 0;
+
+// Initialization
+void klassItable::initialize_itable(bool checkconstraints, TRAPS) {
+ if (_klass->is_interface()) {
+ // This needs to go after vtable indices are assigned but
+ // before implementors need to know the number of itable indices.
+ assign_itable_indices_for_interface(_klass);
+ }
+
+ // Cannot be setup doing bootstrapping, interfaces don't have
+ // itables, and klass with only ones entry have empty itables
+ if (Universe::is_bootstrapping() ||
+ _klass->is_interface() ||
+ _klass->itable_length() == itableOffsetEntry::size()) return;
+
+ // There's alway an extra itable entry so we can null-terminate it.
+ guarantee(size_offset_table() >= 1, "too small");
+ int num_interfaces = size_offset_table() - 1;
+ if (num_interfaces > 0) {
+ log_develop_debug(itables)("%3d: Initializing itables for %s", ++initialize_count,
+ _klass->name()->as_C_string());
+
+
+ // Iterate through all interfaces
+ int i;
+ for(i = 0; i < num_interfaces; i++) {
+ itableOffsetEntry* ioe = offset_entry(i);
+ HandleMark hm(THREAD);
+ Klass* interf = ioe->interface_klass();
+ assert(interf != NULL && ioe->offset() != 0, "bad offset entry in itable");
+ initialize_itable_for_interface(ioe->offset(), interf, checkconstraints, CHECK);
+ }
+
+ }
+ // Check that the last entry is empty
+ itableOffsetEntry* ioe = offset_entry(size_offset_table() - 1);
+ guarantee(ioe->interface_klass() == NULL && ioe->offset() == 0, "terminator entry missing");
+}
+
+
+inline bool interface_method_needs_itable_index(Method* m) {
+ if (m->is_static()) return false; // e.g., Stream.empty
+ if (m->is_initializer()) return false; // <init> or <clinit>
+ if (m->is_private()) return false; // requires invokeSpecial
+ // If an interface redeclares a method from java.lang.Object,
+ // it should already have a vtable index, don't touch it.
+ // e.g., CharSequence.toString (from initialize_vtable)
+ // if (m->has_vtable_index()) return false; // NO!
+ return true;
+}
+
+int klassItable::assign_itable_indices_for_interface(Klass* klass) {
+ // an interface does not have an itable, but its methods need to be numbered
+ log_develop_debug(itables)("%3d: Initializing itable indices for interface %s",
+ ++initialize_count, klass->name()->as_C_string());
+ Array<Method*>* methods = InstanceKlass::cast(klass)->methods();
+ int nof_methods = methods->length();
+ int ime_num = 0;
+ for (int i = 0; i < nof_methods; i++) {
+ Method* m = methods->at(i);
+ if (interface_method_needs_itable_index(m)) {
+ assert(!m->is_final_method(), "no final interface methods");
+ // If m is already assigned a vtable index, do not disturb it.
+ if (log_develop_is_enabled(Trace, itables)) {
+ ResourceMark rm;
+ LogTarget(Trace, itables) lt;
+ LogStream ls(lt);
+ assert(m != NULL, "methods can never be null");
+ const char* sig = m->name_and_sig_as_C_string();
+ if (m->has_vtable_index()) {
+ ls.print("vtable index %d for method: %s, flags: ", m->vtable_index(), sig);
+ } else {
+ ls.print("itable index %d for method: %s, flags: ", ime_num, sig);
+ }
+ m->print_linkage_flags(&ls);
+ ls.cr();
+ }
+ if (!m->has_vtable_index()) {
+ // A shared method could have an initialized itable_index that
+ // is < 0.
+ assert(m->vtable_index() == Method::pending_itable_index ||
+ m->is_shared(),
+ "set by initialize_vtable");
+ m->set_itable_index(ime_num);
+ // Progress to next itable entry
+ ime_num++;
+ }
+ }
+ }
+ assert(ime_num == method_count_for_interface(klass), "proper sizing");
+ return ime_num;
+}
+
+int klassItable::method_count_for_interface(Klass* interf) {
+ assert(interf->is_instance_klass(), "must be");
+ assert(interf->is_interface(), "must be");
+ Array<Method*>* methods = InstanceKlass::cast(interf)->methods();
+ int nof_methods = methods->length();
+ int length = 0;
+ while (nof_methods > 0) {
+ Method* m = methods->at(nof_methods-1);
+ if (m->has_itable_index()) {
+ length = m->itable_index() + 1;
+ break;
+ }
+ nof_methods -= 1;
+ }
+#ifdef ASSERT
+ int nof_methods_copy = nof_methods;
+ while (nof_methods_copy > 0) {
+ Method* mm = methods->at(--nof_methods_copy);
+ assert(!mm->has_itable_index() || mm->itable_index() < length, "");
+ }
+#endif //ASSERT
+ // return the rightmost itable index, plus one; or 0 if no methods have
+ // itable indices
+ return length;
+}
+
+
+void klassItable::initialize_itable_for_interface(int method_table_offset, Klass* interf, bool checkconstraints, TRAPS) {
+ Array<Method*>* methods = InstanceKlass::cast(interf)->methods();
+ int nof_methods = methods->length();
+ HandleMark hm;
+ assert(nof_methods > 0, "at least one method must exist for interface to be in vtable");
+ Handle interface_loader (THREAD, InstanceKlass::cast(interf)->class_loader());
+
+ int ime_count = method_count_for_interface(interf);
+ for (int i = 0; i < nof_methods; i++) {
+ Method* m = methods->at(i);
+ methodHandle target;
+ if (m->has_itable_index()) {
+ // This search must match the runtime resolution, i.e. selection search for invokeinterface
+ // to correctly enforce loader constraints for interface method inheritance
+ target = LinkResolver::lookup_instance_method_in_klasses(_klass, m->name(), m->signature(), CHECK);
+ }
+ if (target == NULL || !target->is_public() || target->is_abstract()) {
+ // Entry does not resolve. Leave it empty for AbstractMethodError.
+ if (!(target == NULL) && !target->is_public()) {
+ // Stuff an IllegalAccessError throwing method in there instead.
+ itableOffsetEntry::method_entry(_klass, method_table_offset)[m->itable_index()].
+ initialize(Universe::throw_illegal_access_error());
+ }
+ } else {
+ // Entry did resolve, check loader constraints before initializing
+ // if checkconstraints requested
+ if (checkconstraints) {
+ Handle method_holder_loader (THREAD, target->method_holder()->class_loader());
+ if (method_holder_loader() != interface_loader()) {
+ ResourceMark rm(THREAD);
+ Symbol* failed_type_symbol =
+ SystemDictionary::check_signature_loaders(m->signature(),
+ method_holder_loader,
+ interface_loader,
+ true, CHECK);
+ if (failed_type_symbol != NULL) {
+ const char* msg = "loader constraint violation in interface "
+ "itable initialization: when resolving method \"%s\" the class"
+ " loader (instance of %s) of the current class, %s, "
+ "and the class loader (instance of %s) for interface "
+ "%s have different Class objects for the type %s "
+ "used in the signature";
+ char* sig = target()->name_and_sig_as_C_string();
+ const char* loader1 = SystemDictionary::loader_name(method_holder_loader());
+ char* current = _klass->name()->as_C_string();
+ const char* loader2 = SystemDictionary::loader_name(interface_loader());
+ char* iface = InstanceKlass::cast(interf)->name()->as_C_string();
+ char* failed_type_name = failed_type_symbol->as_C_string();
+ size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
+ strlen(current) + strlen(loader2) + strlen(iface) +
+ strlen(failed_type_name);
+ char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
+ jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
+ iface, failed_type_name);
+ THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
+ }
+ }
+ }
+
+ // ime may have moved during GC so recalculate address
+ int ime_num = m->itable_index();
+ assert(ime_num < ime_count, "oob");
+ itableOffsetEntry::method_entry(_klass, method_table_offset)[ime_num].initialize(target());
+ if (log_develop_is_enabled(Trace, itables)) {
+ ResourceMark rm(THREAD);
+ if (target() != NULL) {
+ LogTarget(Trace, itables) lt;
+ LogStream ls(lt);
+ char* sig = target()->name_and_sig_as_C_string();
+ ls.print("interface: %s, ime_num: %d, target: %s, method_holder: %s ",
+ interf->internal_name(), ime_num, sig,
+ target()->method_holder()->internal_name());
+ ls.print("target_method flags: ");
+ target()->print_linkage_flags(&ls);
+ ls.cr();
+ }
+ }
+ }
+ }
+}
+
+#if INCLUDE_JVMTI
+// search the itable for uses of either obsolete or EMCP methods
+void klassItable::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
+
+ itableMethodEntry* ime = method_entry(0);
+ for (int i = 0; i < _size_method_table; i++, ime++) {
+ Method* old_method = ime->method();
+ if (old_method == NULL || old_method->method_holder() != holder || !old_method->is_old()) {
+ continue; // skip uninteresting entries
+ }
+ assert(!old_method->is_deleted(), "itable methods may not be deleted");
+
+ Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
+
+ assert(new_method != NULL, "method_with_idnum() should not be NULL");
+ assert(old_method != new_method, "sanity check");
+
+ ime->initialize(new_method);
+
+ if (log_is_enabled(Info, redefine, class, update)) {
+ ResourceMark rm;
+ if (!(*trace_name_printed)) {
+ log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
+ *trace_name_printed = true;
+ }
+ log_trace(redefine, class, update, itables)
+ ("itable method update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string());
+ }
+ }
+}
+
+// an itable should never contain old or obsolete methods
+bool klassItable::check_no_old_or_obsolete_entries() {
+ itableMethodEntry* ime = method_entry(0);
+ for (int i = 0; i < _size_method_table; i++) {
+ Method* m = ime->method();
+ if (m != NULL &&
+ (NOT_PRODUCT(!m->is_valid() ||) m->is_old() || m->is_obsolete())) {
+ return false;
+ }
+ ime++;
+ }
+ return true;
+}
+
+void klassItable::dump_itable() {
+ itableMethodEntry* ime = method_entry(0);
+ tty->print_cr("itable dump --");
+ for (int i = 0; i < _size_method_table; i++) {
+ Method* m = ime->method();
+ if (m != NULL) {
+ tty->print(" (%5d) ", i);
+ m->access_flags().print_on(tty);
+ if (m->is_default_method()) {
+ tty->print("default ");
+ }
+ tty->print(" -- ");
+ m->print_name(tty);
+ tty->cr();
+ }
+ ime++;
+ }
+}
+#endif // INCLUDE_JVMTI
+
+// Setup
+class InterfaceVisiterClosure : public StackObj {
+ public:
+ virtual void doit(Klass* intf, int method_count) = 0;
+};
+
+// Visit all interfaces with at least one itable method
+void visit_all_interfaces(Array<Klass*>* transitive_intf, InterfaceVisiterClosure *blk) {
+ // Handle array argument
+ for(int i = 0; i < transitive_intf->length(); i++) {
+ Klass* intf = transitive_intf->at(i);
+ assert(intf->is_interface(), "sanity check");
+
+ // Find no. of itable methods
+ int method_count = 0;
+ // method_count = klassItable::method_count_for_interface(intf);
+ Array<Method*>* methods = InstanceKlass::cast(intf)->methods();
+ if (methods->length() > 0) {
+ for (int i = methods->length(); --i >= 0; ) {
+ if (interface_method_needs_itable_index(methods->at(i))) {
+ method_count++;
+ }
+ }
+ }
+
+ // Only count interfaces with at least one method
+ if (method_count > 0) {
+ blk->doit(intf, method_count);
+ }
+ }
+}
+
+class CountInterfacesClosure : public InterfaceVisiterClosure {
+ private:
+ int _nof_methods;
+ int _nof_interfaces;
+ public:
+ CountInterfacesClosure() { _nof_methods = 0; _nof_interfaces = 0; }
+
+ int nof_methods() const { return _nof_methods; }
+ int nof_interfaces() const { return _nof_interfaces; }
+
+ void doit(Klass* intf, int method_count) { _nof_methods += method_count; _nof_interfaces++; }
+};
+
+class SetupItableClosure : public InterfaceVisiterClosure {
+ private:
+ itableOffsetEntry* _offset_entry;
+ itableMethodEntry* _method_entry;
+ address _klass_begin;
+ public:
+ SetupItableClosure(address klass_begin, itableOffsetEntry* offset_entry, itableMethodEntry* method_entry) {
+ _klass_begin = klass_begin;
+ _offset_entry = offset_entry;
+ _method_entry = method_entry;
+ }
+
+ itableMethodEntry* method_entry() const { return _method_entry; }
+
+ void doit(Klass* intf, int method_count) {
+ int offset = ((address)_method_entry) - _klass_begin;
+ _offset_entry->initialize(intf, offset);
+ _offset_entry++;
+ _method_entry += method_count;
+ }
+};
+
+int klassItable::compute_itable_size(Array<Klass*>* transitive_interfaces) {
+ // Count no of interfaces and total number of interface methods
+ CountInterfacesClosure cic;
+ visit_all_interfaces(transitive_interfaces, &cic);
+
+ // There's alway an extra itable entry so we can null-terminate it.
+ int itable_size = calc_itable_size(cic.nof_interfaces() + 1, cic.nof_methods());
+
+ // Statistics
+ update_stats(itable_size * wordSize);
+
+ return itable_size;
+}
+
+
+// Fill out offset table and interface klasses into the itable space
+void klassItable::setup_itable_offset_table(InstanceKlass* klass) {
+ if (klass->itable_length() == 0) return;
+ assert(!klass->is_interface(), "Should have zero length itable");
+
+ // Count no of interfaces and total number of interface methods
+ CountInterfacesClosure cic;
+ visit_all_interfaces(klass->transitive_interfaces(), &cic);
+ int nof_methods = cic.nof_methods();
+ int nof_interfaces = cic.nof_interfaces();
+
+ // Add one extra entry so we can null-terminate the table
+ nof_interfaces++;
+
+ assert(compute_itable_size(klass->transitive_interfaces()) ==
+ calc_itable_size(nof_interfaces, nof_methods),
+ "mismatch calculation of itable size");
+
+ // Fill-out offset table
+ itableOffsetEntry* ioe = (itableOffsetEntry*)klass->start_of_itable();
+ itableMethodEntry* ime = (itableMethodEntry*)(ioe + nof_interfaces);
+ intptr_t* end = klass->end_of_itable();
+ assert((oop*)(ime + nof_methods) <= (oop*)klass->start_of_nonstatic_oop_maps(), "wrong offset calculation (1)");
+ assert((oop*)(end) == (oop*)(ime + nof_methods), "wrong offset calculation (2)");
+
+ // Visit all interfaces and initialize itable offset table
+ SetupItableClosure sic((address)klass, ioe, ime);
+ visit_all_interfaces(klass->transitive_interfaces(), &sic);
+
+#ifdef ASSERT
+ ime = sic.method_entry();
+ oop* v = (oop*) klass->end_of_itable();
+ assert( (oop*)(ime) == v, "wrong offset calculation (2)");
+#endif
+}
+
+
+// inverse to itable_index
+Method* klassItable::method_for_itable_index(Klass* intf, int itable_index) {
+ assert(InstanceKlass::cast(intf)->is_interface(), "sanity check");
+ assert(intf->verify_itable_index(itable_index), "");
+ Array<Method*>* methods = InstanceKlass::cast(intf)->methods();
+
+ if (itable_index < 0 || itable_index >= method_count_for_interface(intf))
+ return NULL; // help caller defend against bad indices
+
+ int index = itable_index;
+ Method* m = methods->at(index);
+ int index2 = -1;
+ while (!m->has_itable_index() ||
+ (index2 = m->itable_index()) != itable_index) {
+ assert(index2 < itable_index, "monotonic");
+ if (++index == methods->length())
+ return NULL;
+ m = methods->at(index);
+ }
+ assert(m->itable_index() == itable_index, "correct inverse");
+
+ return m;
+}
+
+void klassVtable::verify(outputStream* st, bool forced) {
+ // make sure table is initialized
+ if (!Universe::is_fully_initialized()) return;
+#ifndef PRODUCT
+ // avoid redundant verifies
+ if (!forced && _verify_count == Universe::verify_count()) return;
+ _verify_count = Universe::verify_count();
+#endif
+ oop* end_of_obj = (oop*)_klass + _klass->size();
+ oop* end_of_vtable = (oop *)&table()[_length];
+ if (end_of_vtable > end_of_obj) {
+ fatal("klass %s: klass object too short (vtable extends beyond end)",
+ _klass->internal_name());
+ }
+
+ for (int i = 0; i < _length; i++) table()[i].verify(this, st);
+ // verify consistency with superKlass vtable
+ Klass* super = _klass->super();
+ if (super != NULL) {
+ InstanceKlass* sk = InstanceKlass::cast(super);
+ klassVtable vt = sk->vtable();
+ for (int i = 0; i < vt.length(); i++) {
+ verify_against(st, &vt, i);
+ }
+ }
+}
+
+void klassVtable::verify_against(outputStream* st, klassVtable* vt, int index) {
+ vtableEntry* vte = &vt->table()[index];
+ if (vte->method()->name() != table()[index].method()->name() ||
+ vte->method()->signature() != table()[index].method()->signature()) {
+ fatal("mismatched name/signature of vtable entries");
+ }
+}
+
+#ifndef PRODUCT
+void klassVtable::print() {
+ ResourceMark rm;
+ tty->print("klassVtable for klass %s (length %d):\n", _klass->internal_name(), length());
+ for (int i = 0; i < length(); i++) {
+ table()[i].print();
+ tty->cr();
+ }
+}
+#endif
+
+void vtableEntry::verify(klassVtable* vt, outputStream* st) {
+ NOT_PRODUCT(FlagSetting fs(IgnoreLockingAssertions, true));
+ Klass* vtklass = vt->klass();
+ if (vtklass->is_instance_klass() &&
+ (InstanceKlass::cast(vtklass)->major_version() >= klassVtable::VTABLE_TRANSITIVE_OVERRIDE_VERSION)) {
+ assert(method() != NULL, "must have set method");
+ }
+ if (method() != NULL) {
+ method()->verify();
+ // we sub_type, because it could be a miranda method
+ if (!vtklass->is_subtype_of(method()->method_holder())) {
+#ifndef PRODUCT
+ print();
+#endif
+ fatal("vtableEntry " PTR_FORMAT ": method is from subclass", p2i(this));
+ }
+ }
+}
+
+#ifndef PRODUCT
+
+void vtableEntry::print() {
+ ResourceMark rm;
+ tty->print("vtableEntry %s: ", method()->name()->as_C_string());
+ if (Verbose) {
+ tty->print("m " PTR_FORMAT " ", p2i(method()));
+ }
+}
+
+class VtableStats : AllStatic {
+ public:
+ static int no_klasses; // # classes with vtables
+ static int no_array_klasses; // # array classes
+ static int no_instance_klasses; // # instanceKlasses
+ static int sum_of_vtable_len; // total # of vtable entries
+ static int sum_of_array_vtable_len; // total # of vtable entries in array klasses only
+ static int fixed; // total fixed overhead in bytes
+ static int filler; // overhead caused by filler bytes
+ static int entries; // total bytes consumed by vtable entries
+ static int array_entries; // total bytes consumed by array vtable entries
+
+ static void do_class(Klass* k) {
+ Klass* kl = k;
+ klassVtable vt = kl->vtable();
+ no_klasses++;
+ if (kl->is_instance_klass()) {
+ no_instance_klasses++;
+ kl->array_klasses_do(do_class);
+ }
+ if (kl->is_array_klass()) {
+ no_array_klasses++;
+ sum_of_array_vtable_len += vt.length();
+ }
+ sum_of_vtable_len += vt.length();
+ }
+
+ static void compute() {
+ ClassLoaderDataGraph::classes_do(do_class);
+ fixed = no_klasses * oopSize; // vtable length
+ // filler size is a conservative approximation
+ filler = oopSize * (no_klasses - no_instance_klasses) * (sizeof(InstanceKlass) - sizeof(ArrayKlass) - 1);
+ entries = sizeof(vtableEntry) * sum_of_vtable_len;
+ array_entries = sizeof(vtableEntry) * sum_of_array_vtable_len;
+ }
+};
+
+int VtableStats::no_klasses = 0;
+int VtableStats::no_array_klasses = 0;
+int VtableStats::no_instance_klasses = 0;
+int VtableStats::sum_of_vtable_len = 0;
+int VtableStats::sum_of_array_vtable_len = 0;
+int VtableStats::fixed = 0;
+int VtableStats::filler = 0;
+int VtableStats::entries = 0;
+int VtableStats::array_entries = 0;
+
+void klassVtable::print_statistics() {
+ ResourceMark rm;
+ HandleMark hm;
+ VtableStats::compute();
+ tty->print_cr("vtable statistics:");
+ tty->print_cr("%6d classes (%d instance, %d array)", VtableStats::no_klasses, VtableStats::no_instance_klasses, VtableStats::no_array_klasses);
+ int total = VtableStats::fixed + VtableStats::filler + VtableStats::entries;
+ tty->print_cr("%6d bytes fixed overhead (refs + vtable object header)", VtableStats::fixed);
+ tty->print_cr("%6d bytes filler overhead", VtableStats::filler);
+ tty->print_cr("%6d bytes for vtable entries (%d for arrays)", VtableStats::entries, VtableStats::array_entries);
+ tty->print_cr("%6d bytes total", total);
+}
+
+int klassItable::_total_classes; // Total no. of classes with itables
+long klassItable::_total_size; // Total no. of bytes used for itables
+
+void klassItable::print_statistics() {
+ tty->print_cr("itable statistics:");
+ tty->print_cr("%6d classes with itables", _total_classes);
+ tty->print_cr("%6lu K uses for itables (average by class: %ld bytes)", _total_size / K, _total_size / _total_classes);
+}
+
+#endif // PRODUCT