diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/oops/klassVtable.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/oops/klassVtable.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1322 @@ +/* + * 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 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() : "", 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() : "", 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() : "", 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()) + // 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* 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* 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* mirandas = new GrowableArray(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* mirandas = new GrowableArray(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 ) +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 + 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 , 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