Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2010, 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() + sizeof(oopDesc));

   }

   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();

     }

   }

   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(AnonymousClasses, "");

       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 "<unknown>";

   return name()->as_klass_external_name();

 }

 const char* Klass::signature_name() const {

   if (name() == NULL)  return "<unknown>";

   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