jdk8-mips64-public/hotspot: src/share/vm/oops/objArrayKlassKlass.cpp@e1162778c1c8 (annotated)

src/share/vm/oops/objArrayKlassKlass.cpp@e1162778c1c8 (annotated)

src/share/vm/oops/objArrayKlassKlass.cpp

Thu, 07 Apr 2011 09:53:20 -0700

author: johnc
date: Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781: e1162778c1c8
parent 2658: c7f3d0b4570f
child 3682: fc9d8850ab8b
permissions: -rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

 /*
  * 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/javaClasses.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "gc_implementation/shared/markSweep.inline.hpp"
 #include "gc_interface/collectedHeap.inline.hpp"
 #include "oops/instanceKlass.hpp"
 #include "oops/objArrayKlassKlass.hpp"
 #include "oops/oop.inline.hpp"
 #include "oops/oop.inline2.hpp"
 #ifndef SERIALGC
 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
 #include "memory/cardTableRS.hpp"
 #include "oops/oop.pcgc.inline.hpp"
 #endif
 klassOop objArrayKlassKlass::create_klass(TRAPS) {
   objArrayKlassKlass o;
   KlassHandle h_this_klass(THREAD, Universe::klassKlassObj());
   KlassHandle k = base_create_klass(h_this_klass, header_size(), o.vtbl_value(), CHECK_0);
   assert(k()->size() == align_object_size(header_size()), "wrong size for object");
   java_lang_Class::create_mirror(k, CHECK_0); // Allocate mirror
   return k();
 }
 klassOop objArrayKlassKlass::allocate_system_objArray_klass(TRAPS) {
   // system_objArrays have no instance klass, so allocate with fake class, then reset to NULL
   KlassHandle kk(THREAD, Universe::intArrayKlassObj());
   klassOop k = allocate_objArray_klass(1, kk, CHECK_0);
   objArrayKlass* tk = (objArrayKlass*) k->klass_part();
   tk->set_element_klass(NULL);
   tk->set_bottom_klass(NULL);
   return k;
 }
 klassOop objArrayKlassKlass::allocate_objArray_klass(int n, KlassHandle element_klass, TRAPS) {
   objArrayKlassKlassHandle this_oop(THREAD, as_klassOop());
   return allocate_objArray_klass_impl(this_oop, n, element_klass, THREAD);
 }
 klassOop objArrayKlassKlass::allocate_objArray_klass_impl(objArrayKlassKlassHandle this_oop,
                                                           int n, KlassHandle element_klass, TRAPS) {
   // Eagerly allocate the direct array supertype.
   KlassHandle super_klass = KlassHandle();
   if (!Universe::is_bootstrapping()) {
     KlassHandle element_super (THREAD, element_klass->super());
     if (element_super.not_null()) {
       // The element type has a direct super.  E.g., String[] has direct super of Object[].
       super_klass = KlassHandle(THREAD, element_super->array_klass_or_null());
       bool supers_exist = super_klass.not_null();
       // Also, see if the element has secondary supertypes.
       // We need an array type for each.
       objArrayHandle element_supers = objArrayHandle(THREAD,
                                             element_klass->secondary_supers());
       for( int i = element_supers->length()-1; i >= 0; i-- ) {
         klassOop elem_super = (klassOop) element_supers->obj_at(i);
         if (Klass::cast(elem_super)->array_klass_or_null() == NULL) {
           supers_exist = false;
           break;
         }
       }
       if (!supers_exist) {
         // Oops.  Not allocated yet.  Back out, allocate it, and retry.
 #ifndef PRODUCT
         if (WizardMode) {
           tty->print_cr("Must retry array klass creation for depth %d",n);
         }
 #endif
         KlassHandle ek;
         {
           MutexUnlocker mu(MultiArray_lock);
           MutexUnlocker mc(Compile_lock);   // for vtables
           klassOop sk = element_super->array_klass(CHECK_0);
           super_klass = KlassHandle(THREAD, sk);
           for( int i = element_supers->length()-1; i >= 0; i-- ) {
             KlassHandle elem_super (THREAD, element_supers->obj_at(i));
             elem_super->array_klass(CHECK_0);
           }
           // Now retry from the beginning
           klassOop klass_oop = element_klass->array_klass(n, CHECK_0);
           // Create a handle because the enclosing brace, when locking
           // can cause a gc.  Better to have this function return a Handle.
           ek = KlassHandle(THREAD, klass_oop);
         }  // re-lock
         return ek();
       }
     } else {
       // The element type is already Object.  Object[] has direct super of Object.
       super_klass = KlassHandle(THREAD, SystemDictionary::Object_klass());
     }
   }
   // Create type name for klass.
   Symbol* name = NULL;
   if (!element_klass->oop_is_instance() ||
       (name = instanceKlass::cast(element_klass())->array_name()) == NULL) {
     ResourceMark rm(THREAD);
     char *name_str = element_klass->name()->as_C_string();
     int len = element_klass->name()->utf8_length();
     char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
     int idx = 0;
     new_str[idx++] = '[';
     if (element_klass->oop_is_instance()) { // it could be an array or simple type
       new_str[idx++] = 'L';
     }
     memcpy(&new_str[idx], name_str, len * sizeof(char));
     idx += len;
     if (element_klass->oop_is_instance()) {
       new_str[idx++] = ';';
     }
     new_str[idx++] = '\0';
     name = SymbolTable::new_symbol(new_str, CHECK_0);
     if (element_klass->oop_is_instance()) {
       instanceKlass* ik = instanceKlass::cast(element_klass());
       ik->set_array_name(name);
     }
   }
   objArrayKlass o;
   arrayKlassHandle k = arrayKlass::base_create_array_klass(o.vtbl_value(),
                                                            objArrayKlass::header_size(),
                                                           this_oop,
                                                            CHECK_0);
   // Initialize instance variables
   objArrayKlass* oak = objArrayKlass::cast(k());
   oak->set_dimension(n);
   oak->set_element_klass(element_klass());
   oak->set_name(name);
   // decrement refcount because object arrays are not explicitly freed.  The
   // instanceKlass array_name() keeps the name counted while the klass is
   // loaded.
   name->decrement_refcount();
   klassOop bk;
   if (element_klass->oop_is_objArray()) {
     bk = objArrayKlass::cast(element_klass())->bottom_klass();
   } else {
     bk = element_klass();
   }
   assert(bk != NULL && (Klass::cast(bk)->oop_is_instance() || Klass::cast(bk)->oop_is_typeArray()), "invalid bottom klass");
   oak->set_bottom_klass(bk);
   oak->set_layout_helper(array_layout_helper(T_OBJECT));
   assert(oak->oop_is_javaArray(), "sanity");
   assert(oak->oop_is_objArray(), "sanity");
   // Call complete_create_array_klass after all instance variables has been initialized.
   arrayKlass::complete_create_array_klass(k, super_klass, CHECK_0);
   return k();
 }
 void objArrayKlassKlass::oop_follow_contents(oop obj) {
   assert(obj->is_klass(), "must be klass");
   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   MarkSweep::mark_and_push(oak->element_klass_addr());
   MarkSweep::mark_and_push(oak->bottom_klass_addr());
   arrayKlassKlass::oop_follow_contents(obj);
 }
 #ifndef SERIALGC
 void objArrayKlassKlass::oop_follow_contents(ParCompactionManager* cm,
                                              oop obj) {
   assert(obj->is_klass(), "must be klass");
   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   PSParallelCompact::mark_and_push(cm, oak->element_klass_addr());
   PSParallelCompact::mark_and_push(cm, oak->bottom_klass_addr());
   arrayKlassKlass::oop_follow_contents(cm, obj);
 }
 #endif // SERIALGC
 int objArrayKlassKlass::oop_adjust_pointers(oop obj) {
   assert(obj->is_klass(), "must be klass");
   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   MarkSweep::adjust_pointer(oak->element_klass_addr());
   MarkSweep::adjust_pointer(oak->bottom_klass_addr());
   return arrayKlassKlass::oop_adjust_pointers(obj);
 }
 int objArrayKlassKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
   assert(obj->is_klass(), "must be klass");
   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   blk->do_oop(oak->element_klass_addr());
   blk->do_oop(oak->bottom_klass_addr());
   return arrayKlassKlass::oop_oop_iterate(obj, blk);
 }
 int
 objArrayKlassKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
   assert(obj->is_klass(), "must be klass");
   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   oop* addr;
   addr = oak->element_klass_addr();
   if (mr.contains(addr)) blk->do_oop(addr);
   addr = oak->bottom_klass_addr();
   if (mr.contains(addr)) blk->do_oop(addr);
   return arrayKlassKlass::oop_oop_iterate_m(obj, blk, mr);
 }
 #ifndef SERIALGC
 void objArrayKlassKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
   assert(obj->blueprint()->oop_is_objArrayKlass(),"must be an obj array klass");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   oop* p = oak->element_klass_addr();
   if (PSScavenge::should_scavenge(p)) {
     pm->claim_or_forward_depth(p);
   }
   p = oak->bottom_klass_addr();
   if (PSScavenge::should_scavenge(p)) {
     pm->claim_or_forward_depth(p);
   }
   arrayKlassKlass::oop_push_contents(pm, obj);
 }
 int objArrayKlassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
   assert(obj->is_klass(), "must be klass");
   assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   PSParallelCompact::adjust_pointer(oak->element_klass_addr());
   PSParallelCompact::adjust_pointer(oak->bottom_klass_addr());
   return arrayKlassKlass::oop_update_pointers(cm, obj);
 }
 #endif // SERIALGC
 #ifndef PRODUCT
 // Printing
 void objArrayKlassKlass::oop_print_on(oop obj, outputStream* st) {
   assert(obj->is_klass(), "must be klass");
   objArrayKlass* oak = (objArrayKlass*) klassOop(obj)->klass_part();
   klassKlass::oop_print_on(obj, st);
   st->print(" - instance klass: ");
   oak->element_klass()->print_value_on(st);
   st->cr();
 }
 #endif //PRODUCT
 void objArrayKlassKlass::oop_print_value_on(oop obj, outputStream* st) {
   assert(obj->is_klass(), "must be klass");
   objArrayKlass* oak = (objArrayKlass*) klassOop(obj)->klass_part();
   oak->element_klass()->print_value_on(st);
   st->print("[]");
 }
 const char* objArrayKlassKlass::internal_name() const {
   return "{object array class}";
 }
 // Verification
 void objArrayKlassKlass::oop_verify_on(oop obj, outputStream* st) {
   arrayKlassKlass::oop_verify_on(obj, st);
   objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
   guarantee(oak->element_klass()->is_perm(),  "should be in permspace");
   guarantee(oak->element_klass()->is_klass(), "should be klass");
   guarantee(oak->bottom_klass()->is_perm(),   "should be in permspace");
   guarantee(oak->bottom_klass()->is_klass(),  "should be klass");
   Klass* bk = Klass::cast(oak->bottom_klass());
   guarantee(bk->oop_is_instance() || bk->oop_is_typeArray(),  "invalid bottom klass");
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/oops/objArrayKlassKlass.cpp@e1162778c1c8 (annotated)

src/share/vm/oops/objArrayKlassKlass.cpp