/* * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/vmSymbols.hpp" #include "gc_interface/collectedHeap.inline.hpp" #include "memory/oopFactory.hpp" #include "memory/resourceArea.hpp" #include "oops/instanceKlass.hpp" #include "oops/klass.inline.hpp" #include "oops/klassOop.hpp" #include "oops/oop.inline.hpp" #include "oops/oop.inline2.hpp" #include "runtime/atomic.hpp" void Klass::set_name(Symbol* n) { _name = n; if (_name != NULL) _name->increment_refcount(); } bool Klass::is_subclass_of(klassOop k) const { // Run up the super chain and check klassOop t = as_klassOop(); if (t == k) return true; t = Klass::cast(t)->super(); while (t != NULL) { if (t == k) return true; t = Klass::cast(t)->super(); } return false; } bool Klass::search_secondary_supers(klassOop k) const { // Put some extra logic here out-of-line, before the search proper. // This cuts down the size of the inline method. // This is necessary, since I am never in my own secondary_super list. if (this->as_klassOop() == k) return true; // Scan the array-of-objects for a match int cnt = secondary_supers()->length(); for (int i = 0; i < cnt; i++) { if (secondary_supers()->obj_at(i) == k) { ((Klass*)this)->set_secondary_super_cache(k); return true; } } return false; } // Return self, except for abstract classes with exactly 1 // implementor. Then return the 1 concrete implementation. Klass *Klass::up_cast_abstract() { Klass *r = this; while( r->is_abstract() ) { // Receiver is abstract? Klass *s = r->subklass(); // Check for exactly 1 subklass if( !s || s->next_sibling() ) // Oops; wrong count; give up return this; // Return 'this' as a no-progress flag r = s; // Loop till find concrete class } return r; // Return the 1 concrete class } // Find LCA in class hierarchy Klass *Klass::LCA( Klass *k2 ) { Klass *k1 = this; while( 1 ) { if( k1->is_subtype_of(k2->as_klassOop()) ) return k2; if( k2->is_subtype_of(k1->as_klassOop()) ) return k1; k1 = k1->super()->klass_part(); k2 = k2->super()->klass_part(); } } void Klass::check_valid_for_instantiation(bool throwError, TRAPS) { ResourceMark rm(THREAD); THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError() : vmSymbols::java_lang_InstantiationException(), external_name()); } void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) { THROW(vmSymbols::java_lang_ArrayStoreException()); } void Klass::initialize(TRAPS) { ShouldNotReachHere(); } bool Klass::compute_is_subtype_of(klassOop k) { assert(k->is_klass(), "argument must be a class"); return is_subclass_of(k); } methodOop Klass::uncached_lookup_method(Symbol* name, Symbol* signature) const { #ifdef ASSERT tty->print_cr("Error: uncached_lookup_method called on a klass oop." " Likely error: reflection method does not correctly" " wrap return value in a mirror object."); #endif ShouldNotReachHere(); return NULL; } klassOop Klass::base_create_klass_oop(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS) { size = align_object_size(size); // allocate and initialize vtable Klass* kl = (Klass*) vtbl.allocate_permanent(klass, size, CHECK_NULL); klassOop k = kl->as_klassOop(); { // Preinitialize supertype information. // A later call to initialize_supers() may update these settings: kl->set_super(NULL); for (juint i = 0; i < Klass::primary_super_limit(); i++) { kl->_primary_supers[i] = NULL; } kl->set_secondary_supers(NULL); oop_store_without_check((oop*) &kl->_primary_supers[0], k); kl->set_super_check_offset(primary_supers_offset_in_bytes()); } kl->set_java_mirror(NULL); kl->set_modifier_flags(0); kl->set_layout_helper(Klass::_lh_neutral_value); kl->set_name(NULL); AccessFlags af; af.set_flags(0); kl->set_access_flags(af); kl->set_subklass(NULL); kl->set_next_sibling(NULL); kl->set_alloc_count(0); kl->set_alloc_size(0); kl->set_prototype_header(markOopDesc::prototype()); kl->set_biased_lock_revocation_count(0); kl->set_last_biased_lock_bulk_revocation_time(0); return k; } KlassHandle Klass::base_create_klass(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS) { klassOop ek = base_create_klass_oop(klass, size, vtbl, THREAD); return KlassHandle(THREAD, ek); } void Klass_vtbl::post_new_init_klass(KlassHandle& klass, klassOop new_klass, int size) const { assert(!new_klass->klass_part()->null_vtbl(), "Not a complete klass"); CollectedHeap::post_allocation_install_obj_klass(klass, new_klass, size); } void* Klass_vtbl::operator new(size_t ignored, KlassHandle& klass, int size, TRAPS) { // The vtable pointer is installed during the execution of // constructors in the call to permanent_obj_allocate(). Delay // the installation of the klass pointer into the new klass "k" // until after the vtable pointer has been installed (i.e., until // after the return of permanent_obj_allocate(). klassOop k = (klassOop) CollectedHeap::permanent_obj_allocate_no_klass_install(klass, size, CHECK_NULL); return k->klass_part(); } jint Klass::array_layout_helper(BasicType etype) { assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype"); // Note that T_ARRAY is not allowed here. int hsize = arrayOopDesc::base_offset_in_bytes(etype); int esize = type2aelembytes(etype); bool isobj = (etype == T_OBJECT); int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value; int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize)); assert(lh < (int)_lh_neutral_value, "must look like an array layout"); assert(layout_helper_is_javaArray(lh), "correct kind"); assert(layout_helper_is_objArray(lh) == isobj, "correct kind"); assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind"); assert(layout_helper_header_size(lh) == hsize, "correct decode"); assert(layout_helper_element_type(lh) == etype, "correct decode"); assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode"); return lh; } bool Klass::can_be_primary_super_slow() const { if (super() == NULL) return true; else if (super()->klass_part()->super_depth() >= primary_super_limit()-1) return false; else return true; } void Klass::initialize_supers(klassOop k, TRAPS) { if (FastSuperclassLimit == 0) { // None of the other machinery matters. set_super(k); return; } if (k == NULL) { set_super(NULL); oop_store_without_check((oop*) &_primary_supers[0], (oop) this->as_klassOop()); assert(super_depth() == 0, "Object must already be initialized properly"); } else if (k != super() || k == SystemDictionary::Object_klass()) { assert(super() == NULL || super() == SystemDictionary::Object_klass(), "initialize this only once to a non-trivial value"); set_super(k); Klass* sup = k->klass_part(); int sup_depth = sup->super_depth(); juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit()); if (!can_be_primary_super_slow()) my_depth = primary_super_limit(); for (juint i = 0; i < my_depth; i++) { oop_store_without_check((oop*) &_primary_supers[i], (oop) sup->_primary_supers[i]); } klassOop *super_check_cell; if (my_depth < primary_super_limit()) { oop_store_without_check((oop*) &_primary_supers[my_depth], (oop) this->as_klassOop()); super_check_cell = &_primary_supers[my_depth]; } else { // Overflow of the primary_supers array forces me to be secondary. super_check_cell = &_secondary_super_cache; } set_super_check_offset((address)super_check_cell - (address) this->as_klassOop()); #ifdef ASSERT { juint j = super_depth(); assert(j == my_depth, "computed accessor gets right answer"); klassOop t = as_klassOop(); while (!Klass::cast(t)->can_be_primary_super()) { t = Klass::cast(t)->super(); j = Klass::cast(t)->super_depth(); } for (juint j1 = j+1; j1 < primary_super_limit(); j1++) { assert(primary_super_of_depth(j1) == NULL, "super list padding"); } while (t != NULL) { assert(primary_super_of_depth(j) == t, "super list initialization"); t = Klass::cast(t)->super(); --j; } assert(j == (juint)-1, "correct depth count"); } #endif } if (secondary_supers() == NULL) { KlassHandle this_kh (THREAD, this); // Now compute the list of secondary supertypes. // Secondaries can occasionally be on the super chain, // if the inline "_primary_supers" array overflows. int extras = 0; klassOop p; for (p = super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) { ++extras; } // Compute the "real" non-extra secondaries. objArrayOop secondary_oops = compute_secondary_supers(extras, CHECK); objArrayHandle secondaries (THREAD, secondary_oops); // Store the extra secondaries in the first array positions: int fillp = extras; for (p = this_kh->super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) { int i; // Scan for overflow primaries being duplicates of 2nd'arys // This happens frequently for very deeply nested arrays: the // primary superclass chain overflows into the secondary. The // secondary list contains the element_klass's secondaries with // an extra array dimension added. If the element_klass's // secondary list already contains some primary overflows, they // (with the extra level of array-ness) will collide with the // normal primary superclass overflows. for( i = extras; i < secondaries->length(); i++ ) if( secondaries->obj_at(i) == p ) break; if( i < secondaries->length() ) continue; // It's a dup, don't put it in secondaries->obj_at_put(--fillp, p); } // See if we had some dup's, so the array has holes in it. if( fillp > 0 ) { // Pack the array. Drop the old secondaries array on the floor // and let GC reclaim it. objArrayOop s2 = oopFactory::new_system_objArray(secondaries->length() - fillp, CHECK); for( int i = 0; i < s2->length(); i++ ) s2->obj_at_put( i, secondaries->obj_at(i+fillp) ); secondaries = objArrayHandle(THREAD, s2); } #ifdef ASSERT if (secondaries() != Universe::the_array_interfaces_array()) { // We must not copy any NULL placeholders left over from bootstrap. for (int j = 0; j < secondaries->length(); j++) { assert(secondaries->obj_at(j) != NULL, "correct bootstrapping order"); } } #endif this_kh->set_secondary_supers(secondaries()); } } objArrayOop Klass::compute_secondary_supers(int num_extra_slots, TRAPS) { assert(num_extra_slots == 0, "override for complex klasses"); return Universe::the_empty_system_obj_array(); } Klass* Klass::subklass() const { return _subklass == NULL ? NULL : Klass::cast(_subklass); } instanceKlass* Klass::superklass() const { assert(super() == NULL || super()->klass_part()->oop_is_instance(), "must be instance klass"); return _super == NULL ? NULL : instanceKlass::cast(_super); } Klass* Klass::next_sibling() const { return _next_sibling == NULL ? NULL : Klass::cast(_next_sibling); } void Klass::set_subklass(klassOop s) { assert(s != as_klassOop(), "sanity check"); oop_store_without_check((oop*)&_subklass, s); } void Klass::set_next_sibling(klassOop s) { assert(s != as_klassOop(), "sanity check"); oop_store_without_check((oop*)&_next_sibling, s); } void Klass::append_to_sibling_list() { debug_only(if (!SharedSkipVerify) as_klassOop()->verify();) // add ourselves to superklass' subklass list instanceKlass* super = superklass(); if (super == NULL) return; // special case: class Object assert(SharedSkipVerify || (!super->is_interface() // interfaces cannot be supers && (super->superklass() == NULL || !is_interface())), "an interface can only be a subklass of Object"); klassOop prev_first_subklass = super->subklass_oop(); if (prev_first_subklass != NULL) { // set our sibling to be the superklass' previous first subklass set_next_sibling(prev_first_subklass); } // make ourselves the superklass' first subklass super->set_subklass(as_klassOop()); debug_only(if (!SharedSkipVerify) as_klassOop()->verify();) } void Klass::remove_from_sibling_list() { // remove receiver from sibling list instanceKlass* super = superklass(); assert(super != NULL || as_klassOop() == SystemDictionary::Object_klass(), "should have super"); if (super == NULL) return; // special case: class Object if (super->subklass() == this) { // first subklass super->set_subklass(_next_sibling); } else { Klass* sib = super->subklass(); while (sib->next_sibling() != this) { sib = sib->next_sibling(); }; sib->set_next_sibling(_next_sibling); } } void Klass::follow_weak_klass_links( BoolObjectClosure* is_alive, OopClosure* keep_alive) { // This klass is alive but the subklass and siblings are not followed/updated. // We update the subklass link and the subklass' sibling links here. // Our own sibling link will be updated by our superclass (which must be alive // since we are). assert(is_alive->do_object_b(as_klassOop()), "just checking, this should be live"); if (ClassUnloading) { klassOop sub = subklass_oop(); if (sub != NULL && !is_alive->do_object_b(sub)) { // first subklass not alive, find first one alive do { #ifndef PRODUCT if (TraceClassUnloading && WizardMode) { ResourceMark rm; tty->print_cr("[Unlinking class (subclass) %s]", sub->klass_part()->external_name()); } #endif sub = sub->klass_part()->next_sibling_oop(); } while (sub != NULL && !is_alive->do_object_b(sub)); set_subklass(sub); } // now update the subklass' sibling list while (sub != NULL) { klassOop next = sub->klass_part()->next_sibling_oop(); if (next != NULL && !is_alive->do_object_b(next)) { // first sibling not alive, find first one alive do { #ifndef PRODUCT if (TraceClassUnloading && WizardMode) { ResourceMark rm; tty->print_cr("[Unlinking class (sibling) %s]", next->klass_part()->external_name()); } #endif next = next->klass_part()->next_sibling_oop(); } while (next != NULL && !is_alive->do_object_b(next)); sub->klass_part()->set_next_sibling(next); } sub = next; } } else { // Always follow subklass and sibling link. This will prevent any klasses from // being unloaded (all classes are transitively linked from java.lang.Object). keep_alive->do_oop(adr_subklass()); keep_alive->do_oop(adr_next_sibling()); } } void Klass::remove_unshareable_info() { if (oop_is_instance()) { instanceKlass* ik = (instanceKlass*)this; if (ik->is_linked()) { ik->unlink_class(); } } // Clear the Java vtable if the oop has one. // The vtable isn't shareable because it's in the wrong order wrt the methods // once the method names get moved and resorted. klassVtable* vt = vtable(); if (vt != NULL) { assert(oop_is_instance() || oop_is_array(), "nothing else has vtable"); vt->clear_vtable(); } set_subklass(NULL); set_next_sibling(NULL); } void Klass::shared_symbols_iterate(SymbolClosure* closure) { closure->do_symbol(&_name); } klassOop Klass::array_klass_or_null(int rank) { EXCEPTION_MARK; // No exception can be thrown by array_klass_impl when called with or_null == true. // (In anycase, the execption mark will fail if it do so) return array_klass_impl(true, rank, THREAD); } klassOop Klass::array_klass_or_null() { EXCEPTION_MARK; // No exception can be thrown by array_klass_impl when called with or_null == true. // (In anycase, the execption mark will fail if it do so) return array_klass_impl(true, THREAD); } klassOop Klass::array_klass_impl(bool or_null, int rank, TRAPS) { fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass"); return NULL; } klassOop Klass::array_klass_impl(bool or_null, TRAPS) { fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass"); return NULL; } void Klass::with_array_klasses_do(void f(klassOop k)) { f(as_klassOop()); } const char* Klass::external_name() const { if (oop_is_instance()) { instanceKlass* ik = (instanceKlass*) this; if (ik->is_anonymous()) { assert(EnableInvokeDynamic, ""); intptr_t hash = ik->java_mirror()->identity_hash(); char hash_buf[40]; sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash); size_t hash_len = strlen(hash_buf); size_t result_len = name()->utf8_length(); char* result = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1); name()->as_klass_external_name(result, (int) result_len + 1); assert(strlen(result) == result_len, ""); strcpy(result + result_len, hash_buf); assert(strlen(result) == result_len + hash_len, ""); return result; } } if (name() == NULL) return ""; return name()->as_klass_external_name(); } const char* Klass::signature_name() const { if (name() == NULL) return ""; return name()->as_C_string(); } // Unless overridden, modifier_flags is 0. jint Klass::compute_modifier_flags(TRAPS) const { return 0; } int Klass::atomic_incr_biased_lock_revocation_count() { return (int) Atomic::add(1, &_biased_lock_revocation_count); } // Unless overridden, jvmti_class_status has no flags set. jint Klass::jvmti_class_status() const { return 0; } // Printing void Klass::oop_print_on(oop obj, outputStream* st) { ResourceMark rm; // print title st->print_cr("%s ", internal_name()); obj->print_address_on(st); if (WizardMode) { // print header obj->mark()->print_on(st); } // print class st->print(" - klass: "); obj->klass()->print_value_on(st); st->cr(); } void Klass::oop_print_value_on(oop obj, outputStream* st) { // print title ResourceMark rm; // Cannot print in debug mode without this st->print("%s", internal_name()); obj->print_address_on(st); } // Verification void Klass::oop_verify_on(oop obj, outputStream* st) { guarantee(obj->is_oop(), "should be oop"); guarantee(obj->klass()->is_perm(), "should be in permspace"); guarantee(obj->klass()->is_klass(), "klass field is not a klass"); } void Klass::oop_verify_old_oop(oop obj, oop* p, bool allow_dirty) { /* $$$ I think this functionality should be handled by verification of RememberedSet::verify_old_oop(obj, p, allow_dirty, false); the card table. */ } void Klass::oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty) { } #ifndef PRODUCT void Klass::verify_vtable_index(int i) { assert(oop_is_instance() || oop_is_array(), "only instanceKlass and arrayKlass have vtables"); if (oop_is_instance()) { assert(i>=0 && i<((instanceKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds"); } else { assert(i>=0 && i<((arrayKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds"); } } #endif