truffle: src/share/vm/oops/klassVtable.cpp comparison

comparison src/share/vm/oops/klassVtable.cpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	f8236e79048a

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--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 1997-2006 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/_klassVtable.cpp.incl"
+inline instanceKlass* klassVtable::ik() const {
+Klass* k = _klass()->klass_part();
+assert(k->oop_is_instance(), "not an instanceKlass");
+return (instanceKlass*)k;
+}
+// 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.  Let's say there is a 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,
+int &num_miranda_methods,
+klassOop super,
+objArrayOop methods,
+AccessFlags class_flags,
+oop classloader,
+symbolOop classname,
+objArrayOop local_interfaces
+) {
+No_Safepoint_Verifier nsv;
+// set up default result values
+vtable_length = 0;
+num_miranda_methods = 0;
+// start off with super's vtable length
+instanceKlass* sk = (instanceKlass*)super->klass_part();
+vtable_length = super == NULL ? 0 : sk->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->obj_at(i)->is_method(), "must be a methodOop");
+methodOop m = methodOop(methods->obj_at(i));
+if (needs_new_vtable_entry(m, super, classloader, classname, class_flags)) {
+vtable_length += vtableEntry::size(); // we need a new entry
+}
+}
+// compute the number of mirandas methods that must be added to the end
+num_miranda_methods = get_num_mirandas(super, methods, local_interfaces);
+vtable_length += (num_miranda_methods * 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 && !Universe::is_bootstrapping() &&
+vtable_length != Universe::base_vtable_size()) {
+// 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(super != NULL || vtable_length == Universe::base_vtable_size(),
+"bad vtable size for class Object");
+assert(vtable_length % vtableEntry::size() == 0, "bad vtable length");
+assert(vtable_length >= Universe::base_vtable_size(), "vtable too small");
+}
+int klassVtable::index_of(methodOop m, int len) const {
+assert(m->vtable_index() >= 0, "do not ask this of non-vtable methods");
+return m->vtable_index();
+}
+int klassVtable::initialize_from_super(KlassHandle super) {
+if (super.is_null()) {
+return 0;
+} else {
+// copy methods from superKlass
+// can't inherit from array class, so must be instanceKlass
+assert(super->oop_is_instance(), "must be instance klass");
+instanceKlass* sk = (instanceKlass*)super()->klass_part();
+klassVtable* superVtable = sk->vtable();
+assert(superVtable->length() <= _length, "vtable too short");
+#ifdef ASSERT
+superVtable->verify(tty, true);
+#endif
+superVtable->copy_vtable_to(table());
+#ifndef PRODUCT
+if (PrintVtables && Verbose) {
+tty->print_cr("copy vtable from %s to %s size %d", sk->internal_name(), klass()->internal_name(), _length);
+}
+#endif
+return superVtable->length();
+}
+}
+// Revised lookup semantics   introduced 1.3 (Kestral beta)
+void klassVtable::initialize_vtable(bool checkconstraints, TRAPS) {
+// Note:  Arrays can have intermediate array supers.  Use java_super to skip them.
+KlassHandle super (THREAD, klass()->java_super());
+int nofNewEntries = 0;
+if (PrintVtables && !klass()->oop_is_array()) {
+ResourceMark rm(THREAD);
+tty->print_cr("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()) {
+// just clear everything
+for (int i = 0; i < _length; i++) table()[i].clear();
+return;
+}
+int super_vtable_len = initialize_from_super(super);
+if (klass()->oop_is_array()) {
+assert(super_vtable_len == _length, "arrays shouldn't introduce new methods");
+} else {
+assert(_klass->oop_is_instance(), "must be instanceKlass");
+objArrayHandle methods(THREAD, ik()->methods());
+int len = methods()->length();
+int initialized = super_vtable_len;
+// update_super_vtable can stop for gc - ensure using handles
+for (int i = 0; i < len; i++) {
+HandleMark hm(THREAD);
+assert(methods()->obj_at(i)->is_method(), "must be a methodOop");
+methodHandle mh(THREAD, (methodOop)methods()->obj_at(i));
+bool needs_new_entry = update_super_vtable(ik(), mh, super_vtable_len, checkconstraints, CHECK);
+if (needs_new_entry) {
+put_method_at(mh(), initialized);
+mh()->set_vtable_index(initialized); // set primary vtable index
+initialized++;
+}
+}
+// add miranda methods; it will also update the value of initialized
+fill_in_mirandas(initialized);
+// In class hierachieswhere the accesibility is not increasing (i.e., going from private ->
+// package_private -> publicprotected), the vtable might actually be smaller than our initial
+// calculation.
+assert(initialized <= _length, "vtable initialization failed");
+for(;initialized < _length; initialized++) {
+put_method_at(NULL, initialized);
+}
+NOT_PRODUCT(verify(tty, true));
+}
+}
+// Interates through the vtables to find the broadest access level. This
+// will always be monotomic for valid Java programs - but not neccesarily
+// for incompatible class files.
+klassVtable::AccessType klassVtable::vtable_accessibility_at(int i) {
+// This vtable is not implementing the specific method
+if (i >= length()) return acc_private;
+// Compute AccessType for current method. public or protected we are done.
+methodOop m = method_at(i);
+if (m->is_protected() || m->is_public()) return acc_publicprotected;
+AccessType acc = m->is_package_private() ? acc_package_private : acc_private;
+// Compute AccessType for method in super classes
+klassOop super = klass()->super();
+AccessType super_acc = (super != NULL) ? instanceKlass::cast(klass()->super())->vtable()->vtable_accessibility_at(i)
+: acc_private;
+// Merge
+return (AccessType)MAX2((int)acc, (int)super_acc);
+}
+// 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_super_vtable(instanceKlass* klass, methodHandle target_method, int super_vtable_len, bool checkconstraints, TRAPS) {
+ResourceMark rm;
+bool allocate_new = true;
+assert(klass->oop_is_instance(), "must be instanceKlass");
+// 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(methodOopDesc::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 (klass->is_final() || target_method()->is_final()) {
+// 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;
+}
+// we need a new entry if there is no superclass
+if (klass->super() == NULL) {
+return allocate_new;
+}
+// private methods always have a new entry in the vtable
+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, not
+// unhandled oops unless they are reinitialized for each loop
+// handles for name, signature, klass, target_method
+// not for match_method, holder
+symbolHandle name(THREAD,target_method()->name());
+symbolHandle signature(THREAD,target_method()->signature());
+for(int i = 0; i < super_vtable_len; i++) {
+methodOop match_method = method_at(i);
+// Check if method name matches
+if (match_method->name() == name() && match_method->signature() == signature()) {
+instanceKlass* holder = (THREAD, instanceKlass::cast(match_method->method_holder()));
+// Check if the match_method is accessable from current class
+bool same_package_init = false;
+bool same_package_flag = false;
+bool simple_match = match_method->is_public()  || match_method->is_protected();
+if (!simple_match) {
+same_package_init = true;
+same_package_flag = holder->is_same_class_package(_klass->class_loader(), _klass->name());
+simple_match = match_method->is_package_private() && same_package_flag;
+}
+// match_method is the superclass' method. Note we can't override
+// and shouldn't access superclass' ACC_PRIVATE methods
+// (although they have been copied into our vtable)
+// A simple form of this statement is:
+// if ( (match_method->is_public()  || match_method->is_protected()) ||
+//    (match_method->is_package_private() && holder->is_same_class_package(klass->class_loader(), klass->name()))) {
+//
+// The complexity is introduced it avoid recomputing 'is_same_class_package' which is expensive.
+if (simple_match) {
+// Check if target_method and match_method has same level of accessibility. The accesibility of the
+// match method is the "most-general" visibility of all entries at it's particular vtable index for
+// all superclasses. This check must be done before we override the current entry in the vtable.
+AccessType at = vtable_accessibility_at(i);
+bool same_access = false;
+if (  (at == acc_publicprotected && (target_method()->is_public() || target_method()->is_protected())
+|| (at == acc_package_private && (target_method()->is_package_private() &&
+(( same_package_init && same_package_flag) ||
+(!same_package_init && holder->is_same_class_package(_klass->class_loader(), _klass->name()))))))) {
+same_access = true;
+}
+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.
+symbolHandle signature(THREAD, target_method()->signature());
+Handle this_loader(THREAD, _klass->class_loader());
+instanceKlassHandle super_klass(THREAD, _klass->super());
+Handle super_loader(THREAD, super_klass->class_loader());
+if (this_loader() != super_loader()) {
+ResourceMark rm(THREAD);
+char* failed_type_name =
+SystemDictionary::check_signature_loaders(signature, this_loader,
+super_loader, true,
+CHECK_(false));
+if (failed_type_name != 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(this_loader());
+char* current = _klass->name()->as_C_string();
+const char* loader2 = SystemDictionary::loader_name(super_loader());
+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);
+if (same_access) {
+// target and match has same accessiblity - share entry
+allocate_new = false;
+target_method()->set_vtable_index(i);
+#ifndef PRODUCT
+if (PrintVtables && Verbose) {
+AccessType targetacc;
+if (target_method()->is_protected() ||
+target_method()->is_public()) {
+targetacc =  acc_publicprotected;
+} else {
+targetacc = target_method()->is_package_private() ? acc_package_private : acc_private;
+}
+tty->print_cr("overriding with %s::%s index %d, original flags: %x overriders flags: %x",
+_klass->internal_name(), (target_method() != NULL) ?
+target_method()->name()->as_C_string() : "<NULL>", i,
+at, targetacc);
+}
+#endif /*PRODUCT*/
+} else {
+#ifndef PRODUCT
+if (PrintVtables && Verbose) {
+AccessType targetacc;
+if (target_method()->is_protected() ||
+target_method()->is_public()) {
+targetacc =  acc_publicprotected;
+} else {
+targetacc = target_method()->is_package_private() ? acc_package_private : acc_private;
+}
+tty->print_cr("override %s %s::%s at index %d, original flags: %x overriders flags: %x",
+allocate_new ? "+ new" : "only",
+_klass->internal_name(), (target_method() != NULL) ?
+target_method()->name()->as_C_string() : "<NULL>", i,
+at, targetacc);
+}
+#endif /*PRODUCT*/
+}
+}
+}
+}
+return allocate_new;
+}
+void klassVtable::put_method_at(methodOop m, int index) {
+assert(m->is_oop_or_null(), "Not an oop or null");
+#ifndef PRODUCT
+if (PrintVtables && Verbose) {
+tty->print_cr("adding %s::%s at index %d", _klass->internal_name(),
+(m != NULL) ? m->name()->as_C_string() : "<NULL>", index);
+}
+assert(unchecked_method_at(index)->is_oop_or_null(), "Not an oop or null");
+#endif
+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,
+// when the Universe is boostrapping, a super's vtable might not be initialized.
+bool klassVtable::needs_new_vtable_entry(methodOop target_method,
+klassOop super,
+oop classloader,
+symbolOop classname,
+AccessFlags class_flags) {
+if ((class_flags.is_final() || target_method->is_final()) ||
+// 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;
+}
+// we need a new entry if there is no superclass
+if (super == NULL) {
+return true;
+}
+// private methods always have a new entry in the vtable
+if (target_method->is_private()) {
+return true;
+}
+// search through the super class hierarchy to see if we need
+// a new entry
+symbolOop name = target_method->name();
+symbolOop signature = target_method->signature();
+klassOop k = super;
+methodOop match_method = NULL;
+instanceKlass *holder = NULL;
+while (k != NULL) {
+// lookup through the hierarchy for a method with matching name and sign.
+match_method = instanceKlass::cast(k)->lookup_method(name, signature);
+if (match_method == NULL) {
+break; // we still have to search for a matching miranda method
+}
+// get the class holding the matching method
+holder = instanceKlass::cast(match_method->method_holder());
+if (!match_method->is_static()) { // we want only instance method matches
+if ((target_method->is_public() || target_method->is_protected()) &&
+(match_method->is_public()  || match_method->is_protected())) {
+// target and match are public/protected; we do not need a new entry
+return false;
+}
+if (target_method->is_package_private() &&
+match_method->is_package_private() &&
+holder->is_same_class_package(classloader, classname)) {
+// target and match are P private; we do not need a new entry
+return false;
+}
+}
+k = holder->super(); // haven't found a match yet; continue to look
+}
+// if the target method is public or protected it may have a matching
+// miranda method in the super, whose entry it should re-use.
+if (target_method->is_public() || target_method->is_protected()) {
+instanceKlass *sk = instanceKlass::cast(super);
+if (sk->has_miranda_methods()) {
+if (sk->lookup_method_in_all_interfaces(name, signature) != 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(symbolOop name, symbolOop signature) {
+// search from the bottom, might be faster
+for (int i = (length() - 1); i >= 0; i--) {
+methodOop m = table()[i].method();
+if (is_miranda_entry_at(i) &&
+m->name() == name && m->signature() == signature) {
+return i;
+}
+}
+return methodOopDesc::invalid_vtable_index;
+}
+// check if an entry is miranda
+bool klassVtable::is_miranda_entry_at(int i) {
+methodOop m = method_at(i);
+klassOop method_holder = m->method_holder();
+instanceKlass *mhk = instanceKlass::cast(method_holder);
+// miranda methods are interface methods in a class's vtable
+if (mhk->is_interface()) {
+assert(m->is_public() && m->is_abstract(), "should be public and abstract");
+assert(ik()->implements_interface(method_holder) , "this class should implement the interface");
+assert(is_miranda(m, ik()->methods(), ik()->super()), "should be a miranda_method");
+return true;
+}
+return false;
+}
+// check if a method is a miranda method, given a class's methods table and it's super
+// the caller must make sure that the method belongs to an interface implemented by the class
+bool klassVtable::is_miranda(methodOop m, objArrayOop class_methods, klassOop super) {
+symbolOop name = m->name();
+symbolOop signature = m->signature();
+if (instanceKlass::find_method(class_methods, name, signature) == NULL) {
+// did not find it in the method table of the current class
+if (super == NULL) {
+// super doesn't exist
+return true;
+} else {
+if (instanceKlass::cast(super)->lookup_method(name, signature) == NULL) {
+// super class hierarchy does not implement it
+return true;
+}
+}
+}
+return false;
+}
+void klassVtable::add_new_mirandas_to_list(GrowableArray<methodOop>* list_of_current_mirandas,
+objArrayOop current_interface_methods,
+objArrayOop class_methods,
+klassOop 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++) {
+methodOop im = methodOop(current_interface_methods->obj_at(i));
+bool is_duplicate = false;
+int num_of_current_mirandas = list_of_current_mirandas->length();
+// check for duplicate mirandas in different interfaces we implement
+for (int j = 0; j < num_of_current_mirandas; j++) {
+methodOop miranda = list_of_current_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, super)) { // is it a miranda at all?
+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()) == NULL) {
+list_of_current_mirandas->append(im);
+}
+}
+}
+}
+}
+void klassVtable::get_mirandas(GrowableArray<methodOop>* mirandas,
+klassOop super, objArrayOop class_methods,
+objArrayOop local_interfaces) {
+assert((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(klassOop(local_interfaces->obj_at(i)));
+add_new_mirandas_to_list(mirandas, ik->methods(), class_methods, super);
+// iterate thru each local's super interfaces
+objArrayOop 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(klassOop(super_ifs->obj_at(j)));
+add_new_mirandas_to_list(mirandas, sik->methods(), class_methods, super);
+}
+}
+}
+// get number of mirandas
+int klassVtable::get_num_mirandas(klassOop super, objArrayOop class_methods, objArrayOop local_interfaces) {
+ResourceMark rm;
+GrowableArray<methodOop>* mirandas = new GrowableArray<methodOop>(20);
+get_mirandas(mirandas, super, class_methods, local_interfaces);
+return mirandas->length();
+}
+// fill in mirandas
+void klassVtable::fill_in_mirandas(int& initialized) {
+ResourceMark rm;
+GrowableArray<methodOop>* mirandas = new GrowableArray<methodOop>(20);
+instanceKlass *this_ik = ik();
+get_mirandas(mirandas, this_ik->super(), this_ik->methods(), this_ik->local_interfaces());
+int num_mirandas = mirandas->length();
+for (int i = 0; i < num_mirandas; i++) {
+put_method_at(mirandas->at(i), initialized);
+initialized++;
+}
+}
+void klassVtable::copy_vtable_to(vtableEntry* start) {
+Copy::disjoint_words((HeapWord*)table(), (HeapWord*)start, _length * vtableEntry::size());
+}
+void klassVtable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
+int methods_length, bool * trace_name_printed) {
+// search the vtable for uses of either obsolete or EMCP methods
+for (int j = 0; j < methods_length; j++) {
+methodOop old_method = old_methods[j];
+methodOop new_method = new_methods[j];
+// In the vast majority of cases we could get the vtable index
+// by using:  old_method->vtable_index()
+// However, there are rare cases, eg. sun.awt.X11.XDecoratedPeer.getX()
+// in sun.awt.X11.XFramePeer where methods occur more than once in the
+// vtable, so, alas, we must do an exhaustive search.
+for (int index = 0; index < length(); index++) {
+if (unchecked_method_at(index) == old_method) {
+put_method_at(new_method, index);
+if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
+if (!(*trace_name_printed)) {
+// RC_TRACE_MESG macro has an embedded ResourceMark
+RC_TRACE_MESG(("adjust: name=%s",
+Klass::cast(old_method->method_holder())->external_name()));
+*trace_name_printed = true;
+}
+// RC_TRACE macro has an embedded ResourceMark
+RC_TRACE(0x00100000, ("vtable method update: %s(%s)",
+new_method->name()->as_C_string(),
+new_method->signature()->as_C_string()));
+}
+}
+}
+}
+}
+// Garbage collection
+void klassVtable::oop_follow_contents() {
+int len = length();
+for (int i = 0; i < len; i++) {
+MarkSweep::mark_and_push(adr_method_at(i));
+}
+}
+#ifndef SERIALGC
+void klassVtable::oop_follow_contents(ParCompactionManager* cm) {
+int len = length();
+for (int i = 0; i < len; i++) {
+PSParallelCompact::mark_and_push(cm, adr_method_at(i));
+}
+}
+#endif // SERIALGC
+void klassVtable::oop_adjust_pointers() {
+int len = length();
+for (int i = 0; i < len; i++) {
+MarkSweep::adjust_pointer(adr_method_at(i));
+}
+}
+#ifndef SERIALGC
+void klassVtable::oop_update_pointers(ParCompactionManager* cm) {
+const int n = length();
+for (int i = 0; i < n; i++) {
+PSParallelCompact::adjust_pointer(adr_method_at(i));
+}
+}
+void klassVtable::oop_update_pointers(ParCompactionManager* cm,
+HeapWord* beg_addr, HeapWord* end_addr) {
+const int n = length();
+const int entry_size = vtableEntry::size();
+int beg_idx = 0;
+HeapWord* const method_0 = (HeapWord*)adr_method_at(0);
+if (beg_addr > method_0) {
+// it's safe to use cast, as we have guarantees on vtable size to be sane
+beg_idx = int((pointer_delta(beg_addr, method_0) + entry_size - 1) / entry_size);
+}
+oop* const beg_oop = adr_method_at(beg_idx);
+oop* const end_oop = MIN2((oop*)end_addr, adr_method_at(n));
+for (oop* cur_oop = beg_oop; cur_oop < end_oop; cur_oop += entry_size) {
+PSParallelCompact::adjust_pointer(cur_oop);
+}
+}
+#endif // SERIALGC
+// Iterators
+void klassVtable::oop_oop_iterate(OopClosure* blk) {
+int len = length();
+for (int i = 0; i < len; i++) {
+blk->do_oop(adr_method_at(i));
+}
+}
+void klassVtable::oop_oop_iterate_m(OopClosure* blk, MemRegion mr) {
+int len = length();
+int i;
+for (i = 0; i < len; i++) {
+if ((HeapWord*)adr_method_at(i) >= mr.start()) break;
+}
+for (; i < len; i++) {
+oop* adr = adr_method_at(i);
+if ((HeapWord*)adr < mr.end()) blk->do_oop(adr);
+}
+}
+//-----------------------------------------------------------------------------------------
+// Itable code
+// Initialize a itableMethodEntry
+void itableMethodEntry::initialize(methodOop m) {
+if (m == NULL) return;
+_method = m;
+}
+klassItable::klassItable(instanceKlassHandle 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->as_klassOop()) + offset_entry->offset());
+intptr_t* end         = klass->end_of_itable();
+_table_offset      = (intptr_t*)offset_entry - (intptr_t*)klass->as_klassOop();
+_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;
+}
+}
+// This lenght of the itable was either zero, or it has not yet been initialized.
+_table_offset      = 0;
+_size_offset_table = 0;
+_size_method_table = 0;
+}
+// Garbage Collection
+void klassItable::oop_follow_contents() {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+MarkSweep::mark_and_push((oop*)&ioe->_interface);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+MarkSweep::mark_and_push((oop*)&ime->_method);
+ime++;
+}
+}
+#ifndef SERIALGC
+void klassItable::oop_follow_contents(ParCompactionManager* cm) {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+PSParallelCompact::mark_and_push(cm, (oop*)&ioe->_interface);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+PSParallelCompact::mark_and_push(cm, (oop*)&ime->_method);
+ime++;
+}
+}
+#endif // SERIALGC
+void klassItable::oop_adjust_pointers() {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+MarkSweep::adjust_pointer((oop*)&ioe->_interface);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+MarkSweep::adjust_pointer((oop*)&ime->_method);
+ime++;
+}
+}
+#ifndef SERIALGC
+void klassItable::oop_update_pointers(ParCompactionManager* cm) {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+PSParallelCompact::adjust_pointer((oop*)&ioe->_interface);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+PSParallelCompact::adjust_pointer((oop*)&ime->_method);
+ime++;
+}
+}
+void klassItable::oop_update_pointers(ParCompactionManager* cm,
+HeapWord* beg_addr, HeapWord* end_addr) {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+oop* p = (oop*)&ioe->_interface;
+PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+oop* p = (oop*)&ime->_method;
+PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
+ime++;
+}
+}
+#endif // SERIALGC
+// Iterators
+void klassItable::oop_oop_iterate(OopClosure* blk) {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+blk->do_oop((oop*)&ioe->_interface);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+blk->do_oop((oop*)&ime->_method);
+ime++;
+}
+}
+void klassItable::oop_oop_iterate_m(OopClosure* blk, MemRegion mr) {
+// offset table
+itableOffsetEntry* ioe = offset_entry(0);
+for(int i = 0; i < _size_offset_table; i++) {
+oop* adr = (oop*)&ioe->_interface;
+if (mr.contains(adr)) blk->do_oop(adr);
+ioe++;
+}
+// method table
+itableMethodEntry* ime = method_entry(0);
+for(int j = 0; j < _size_method_table; j++) {
+oop* adr = (oop*)&ime->_method;
+if (mr.contains(adr)) blk->do_oop(adr);
+ime++;
+}
+}
+static int initialize_count = 0;
+// Initialization
+void klassItable::initialize_itable(bool checkconstraints, TRAPS) {
+// Cannot be setup doing bootstrapping
+if (Universe::is_bootstrapping()) return;
+int num_interfaces = nof_interfaces();
+if (num_interfaces > 0) {
+if (TraceItables) tty->print_cr("%3d: Initializing itables for %s", ++initialize_count, _klass->name()->as_C_string());
+// In debug mode, we got an extra NULL/NULL entry
+debug_only(num_interfaces--);
+assert(num_interfaces > 0, "to few interfaces in offset itable");
+// Interate through all interfaces
+int i;
+for(i = 0; i < num_interfaces; i++) {
+itableOffsetEntry* ioe = offset_entry(i);
+KlassHandle interf_h (THREAD, ioe->interface_klass());
+assert(interf_h() != NULL && ioe->offset() != 0, "bad offset entry in itable");
+initialize_itable_for_interface(ioe->offset(), interf_h, checkconstraints, CHECK);
+}
+#ifdef ASSERT
+// Check that the last entry is empty
+itableOffsetEntry* ioe = offset_entry(i);
+assert(ioe->interface_klass() == NULL && ioe->offset() == 0, "terminator entry missing");
+#endif
+}
+}
+void klassItable::initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS) {
+objArrayHandle methods(THREAD, instanceKlass::cast(interf_h())->methods());
+int nof_methods = methods()->length();
+HandleMark hm;
+KlassHandle klass = _klass;
+assert(nof_methods > 0, "at least one method must exist for interface to be in vtable")
+Handle interface_loader (THREAD, instanceKlass::cast(interf_h())->class_loader());
+int ime_num = 0;
+// Skip first methodOop if it is a class initializer
+int i = ((methodOop)methods()->obj_at(0))->name() != vmSymbols::class_initializer_name() ? 0 : 1;
+// m, method_name, method_signature, klass reset each loop so they
+// don't need preserving across check_signature_loaders call
+// methods needs a handle in case of gc from check_signature_loaders
+for(; i < nof_methods; i++) {
+methodOop m = (methodOop)methods()->obj_at(i);
+symbolOop method_name = m->name();
+symbolOop method_signature = m->signature();
+// This is same code as in Linkresolver::lookup_instance_method_in_klasses
+methodOop target = klass->uncached_lookup_method(method_name, method_signature);
+while (target != NULL && target->is_static()) {
+// continue with recursive lookup through the superclass
+klassOop super = Klass::cast(target->method_holder())->super();
+target = (super == NULL) ? methodOop(NULL) : Klass::cast(super)->uncached_lookup_method(method_name, method_signature);
+}
+if (target == NULL || !target->is_public() || target->is_abstract()) {
+// Entry do not resolve. Leave it empty
+} else {
+// Entry did resolve, check loader constraints before initializing
+// if checkconstraints requested
+methodHandle  target_h (THREAD, target); // preserve across gc
+if (checkconstraints) {
+Handle method_holder_loader (THREAD, instanceKlass::cast(target->method_holder())->class_loader());
+if (method_holder_loader() != interface_loader()) {
+ResourceMark rm(THREAD);
+char* failed_type_name =
+SystemDictionary::check_signature_loaders(method_signature,
+method_holder_loader,
+interface_loader,
+true, CHECK);
+if (failed_type_name != 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_h()->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_h())->name()->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
+itableOffsetEntry::method_entry(_klass(), method_table_offset)[ime_num].initialize(target_h());
+}
+// Progress to next entry
+ime_num++;
+}
+}
+// Update entry for specic methodOop
+void klassItable::initialize_with_method(methodOop m) {
+itableMethodEntry* ime = method_entry(0);
+for(int i = 0; i < _size_method_table; i++) {
+if (ime->method() == m) {
+ime->initialize(m);
+}
+ime++;
+}
+}
+void klassItable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
+int methods_length, bool * trace_name_printed) {
+// search the itable for uses of either obsolete or EMCP methods
+for (int j = 0; j < methods_length; j++) {
+methodOop old_method = old_methods[j];
+methodOop new_method = new_methods[j];
+itableMethodEntry* ime = method_entry(0);
+for (int i = 0; i < _size_method_table; i++) {
+if (ime->method() == old_method) {
+ime->initialize(new_method);
+if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
+if (!(*trace_name_printed)) {
+// RC_TRACE_MESG macro has an embedded ResourceMark
+RC_TRACE_MESG(("adjust: name=%s",
+Klass::cast(old_method->method_holder())->external_name()));
+*trace_name_printed = true;
+}
+// RC_TRACE macro has an embedded ResourceMark
+RC_TRACE(0x00200000, ("itable method update: %s(%s)",
+new_method->name()->as_C_string(),
+new_method->signature()->as_C_string()));
+}
+break;
+}
+ime++;
+}
+}
+}
+// Setup
+class InterfaceVisiterClosure : public StackObj {
+public:
+virtual void doit(klassOop intf, int method_count) = 0;
+};
+// Visit all interfaces with at-least one method (excluding <clinit>)
+void visit_all_interfaces(objArrayOop transitive_intf, InterfaceVisiterClosure *blk) {
+// Handle array argument
+for(int i = 0; i < transitive_intf->length(); i++) {
+klassOop intf = (klassOop)transitive_intf->obj_at(i);
+assert(Klass::cast(intf)->is_interface(), "sanity check");
+// Find no. of methods excluding a <clinit>
+int method_count = instanceKlass::cast(intf)->methods()->length();
+if (method_count > 0) {
+methodOop m = (methodOop)instanceKlass::cast(intf)->methods()->obj_at(0);
+assert(m != NULL && m->is_method(), "sanity check");
+if (m->name() == vmSymbols::object_initializer_name()) {
+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(klassOop 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(klassOop 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(objArrayHandle transitive_interfaces) {
+// Count no of interfaces and total number of interface methods
+CountInterfacesClosure cic;
+visit_all_interfaces(transitive_interfaces(), &cic);
+// Add one extra entry in debug mode, so we can null-terminate the table
+int nof_methods    = cic.nof_methods();
+int nof_interfaces = cic.nof_interfaces();
+debug_only(if (nof_interfaces > 0) nof_interfaces++);
+int itable_size = calc_itable_size(nof_interfaces, nof_methods);
+// Statistics
+update_stats(itable_size * HeapWordSize);
+return itable_size;
+}
+// Fill out offset table and interface klasses into the itable space
+void klassItable::setup_itable_offset_table(instanceKlassHandle 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 in debug mode, so we can null-terminate the table
+debug_only(if (nof_interfaces > 0) nof_interfaces++);
+assert(compute_itable_size(objArrayHandle(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) <= klass->start_of_static_fields(), "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->as_klassOop(), 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
+}
+// m must be a method in an interface
+int klassItable::compute_itable_index(methodOop m) {
+klassOop intf = m->method_holder();
+assert(instanceKlass::cast(intf)->is_interface(), "sanity check");
+objArrayOop methods = instanceKlass::cast(intf)->methods();
+int index = 0;
+while(methods->obj_at(index) != m) {
+index++;
+assert(index < methods->length(), "should find index for resolve_invoke");
+}
+// Adjust for <clinit>, which is left out of table if first method
+if (methods->length() > 0 && ((methodOop)methods->obj_at(0))->name() == vmSymbols::class_initializer_name()) {
+index--;
+}
+return index;
+}
+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) {
+fatal1("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
+klassOop 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));
+assert(method() != NULL, "must have set method");
+method()->verify();
+// we sub_type, because it could be a miranda method
+if (!vt->klass()->is_subtype_of(method()->method_holder())) {
+#ifndef PRODUCT
+print();
+#endif
+fatal1("vtableEntry %#lx: method is from subclass", this);
+}
+}
+#ifndef PRODUCT
+void vtableEntry::print() {
+ResourceMark rm;
+tty->print("vtableEntry %s: ", method()->name()->as_C_string());
+if (Verbose) {
+tty->print("m %#lx ", (address)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(klassOop k) {
+Klass* kl = k->klass_part();
+klassVtable* vt = kl->vtable();
+if (vt == NULL) return;
+no_klasses++;
+if (kl->oop_is_instance()) {
+no_instance_klasses++;
+kl->array_klasses_do(do_class);
+}
+if (kl->oop_is_array()) {
+no_array_klasses++;
+sum_of_array_vtable_len += vt->length();
+}
+sum_of_vtable_len += vt->length();
+}
+static void compute() {
+SystemDictionary::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);
+}
+bool klassVtable::check_no_old_entries() {
+// Check that there really is no entry
+for (int i = 0; i < length(); i++) {
+methodOop m = unchecked_method_at(i);
+if (m != NULL) {
+if (m->is_old()) {
+return false;
+}
+}
+}
+return true;
+}
+void klassVtable::dump_vtable() {
+tty->print_cr("vtable dump --");
+for (int i = 0; i < length(); i++) {
+methodOop m = unchecked_method_at(i);
+if (m != NULL) {
+tty->print("      (%5d)  ", i);
+m->access_flags().print_on(tty);
+tty->print(" --  ");
+m->print_name(tty);
+tty->cr();
+}
+}
+}
+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("%6d K uses for itables (average by class: %d bytes)", _total_size / K, _total_size / _total_classes);
+}
+#endif // PRODUCT

Mercurial > hg > truffle

comparison src/share/vm/oops/klassVtable.cpp @ 0:a61af66fc99e jdk7-b24