view src/share/vm/oops/klassKlass.cpp @ 1091:6aa7255741f3

6906727: UseCompressedOops: some card-marking fixes related to object arrays Summary: Introduced a new write_ref_array(HeapWords* start, size_t count) method that does the requisite MemRegion range calculation so (some of the) clients of the erstwhile write_ref_array(MemRegion mr) do not need to worry. This removed all external uses of array_size(), which was also simplified and made private. Asserts were added to catch other possible issues. Further, less essential, fixes stemming from this investigation are deferred to CR 6904516 (to follow shortly in hs17). Reviewed-by: kvn, coleenp, jmasa
author ysr
date Thu, 03 Dec 2009 15:01:57 -0800
parents a61af66fc99e
children 4e6abf09f540
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/*
 * 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/_klassKlass.cpp.incl"

int klassKlass::oop_size(oop obj) const {
  assert (obj->is_klass(), "must be a klassOop");
  return klassOop(obj)->klass_part()->klass_oop_size();
}

klassOop klassKlass::create_klass(TRAPS) {
  KlassHandle h_this_klass;
  klassKlass o;
  // for bootstrapping, handles may not be available yet.
  klassOop k = base_create_klass_oop(h_this_klass, header_size(), o.vtbl_value(), CHECK_NULL);
  k->set_klass(k); // point to thyself
  // Do not try to allocate mirror, java.lang.Class not loaded at this point.
  // See Universe::fixup_mirrors()
  return k;
}

void klassKlass::oop_follow_contents(oop obj) {
  Klass* k = Klass::cast(klassOop(obj));
  // If we are alive it is valid to keep our superclass and subtype caches alive
  MarkSweep::mark_and_push(k->adr_super());
  for (juint i = 0; i < Klass::primary_super_limit(); i++)
    MarkSweep::mark_and_push(k->adr_primary_supers()+i);
  MarkSweep::mark_and_push(k->adr_secondary_super_cache());
  MarkSweep::mark_and_push(k->adr_secondary_supers());
  MarkSweep::mark_and_push(k->adr_java_mirror());
  MarkSweep::mark_and_push(k->adr_name());
  // We follow the subklass and sibling links at the end of the
  // marking phase, since otherwise following them will prevent
  // class unloading (all classes are transitively linked from
  // java.lang.Object).
  MarkSweep::revisit_weak_klass_link(k);
  obj->follow_header();
}

#ifndef SERIALGC
void klassKlass::oop_follow_contents(ParCompactionManager* cm,
                                     oop obj) {
  Klass* k = Klass::cast(klassOop(obj));
  // If we are alive it is valid to keep our superclass and subtype caches alive
  PSParallelCompact::mark_and_push(cm, k->adr_super());
  for (juint i = 0; i < Klass::primary_super_limit(); i++)
    PSParallelCompact::mark_and_push(cm, k->adr_primary_supers()+i);
  PSParallelCompact::mark_and_push(cm, k->adr_secondary_super_cache());
  PSParallelCompact::mark_and_push(cm, k->adr_secondary_supers());
  PSParallelCompact::mark_and_push(cm, k->adr_java_mirror());
  PSParallelCompact::mark_and_push(cm, k->adr_name());
  // We follow the subklass and sibling links at the end of the
  // marking phase, since otherwise following them will prevent
  // class unloading (all classes are transitively linked from
  // java.lang.Object).
  PSParallelCompact::revisit_weak_klass_link(cm, k);
  obj->follow_header(cm);
}
#endif // SERIALGC

int klassKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
  // Get size before changing pointers
  int size = oop_size(obj);
  Klass* k = Klass::cast(klassOop(obj));
  blk->do_oop(k->adr_super());
  for (juint i = 0; i < Klass::primary_super_limit(); i++)
    blk->do_oop(k->adr_primary_supers()+i);
  blk->do_oop(k->adr_secondary_super_cache());
  blk->do_oop(k->adr_secondary_supers());
  blk->do_oop(k->adr_java_mirror());
  blk->do_oop(k->adr_name());
  // The following are in the perm gen and are treated
  // specially in a later phase of a perm gen collection; ...
  assert(oop(k)->is_perm(), "should be in perm");
  assert(oop(k->subklass())->is_perm_or_null(), "should be in perm");
  assert(oop(k->next_sibling())->is_perm_or_null(), "should be in perm");
  // ... don't scan them normally, but remember this klassKlass
  // for later (see, for instance, oop_follow_contents above
  // for what MarkSweep does with it.
  if (blk->should_remember_klasses()) {
    blk->remember_klass(k);
  }
  obj->oop_iterate_header(blk);
  return size;
}


int klassKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
  // Get size before changing pointers
  int size = oop_size(obj);
  Klass* k = Klass::cast(klassOop(obj));
  oop* adr;
  adr = k->adr_super();
  if (mr.contains(adr)) blk->do_oop(adr);
  for (juint i = 0; i < Klass::primary_super_limit(); i++) {
    adr = k->adr_primary_supers()+i;
    if (mr.contains(adr)) blk->do_oop(adr);
  }
  adr = k->adr_secondary_super_cache();
  if (mr.contains(adr)) blk->do_oop(adr);
  adr = k->adr_secondary_supers();
  if (mr.contains(adr)) blk->do_oop(adr);
  adr = k->adr_java_mirror();
  if (mr.contains(adr)) blk->do_oop(adr);
  adr = k->adr_name();
  if (mr.contains(adr)) blk->do_oop(adr);
  // The following are "weak links" in the perm gen and are
  // treated specially in a later phase of a perm gen collection.
  assert(oop(k)->is_perm(), "should be in perm");
  assert(oop(k->adr_subklass())->is_perm(), "should be in perm");
  assert(oop(k->adr_next_sibling())->is_perm(), "should be in perm");
  if (blk->should_remember_klasses()
      && (mr.contains(k->adr_subklass())
          || mr.contains(k->adr_next_sibling()))) {
    blk->remember_klass(k);
  }
  obj->oop_iterate_header(blk, mr);
  return size;
}


int klassKlass::oop_adjust_pointers(oop obj) {
  // Get size before changing pointers
  int size = oop_size(obj);
  obj->adjust_header();

  Klass* k = Klass::cast(klassOop(obj));

  MarkSweep::adjust_pointer(k->adr_super());
  for (juint i = 0; i < Klass::primary_super_limit(); i++)
    MarkSweep::adjust_pointer(k->adr_primary_supers()+i);
  MarkSweep::adjust_pointer(k->adr_secondary_super_cache());
  MarkSweep::adjust_pointer(k->adr_secondary_supers());
  MarkSweep::adjust_pointer(k->adr_java_mirror());
  MarkSweep::adjust_pointer(k->adr_name());
  MarkSweep::adjust_pointer(k->adr_subklass());
  MarkSweep::adjust_pointer(k->adr_next_sibling());
  return size;
}

#ifndef SERIALGC
void klassKlass::oop_copy_contents(PSPromotionManager* pm, oop obj) {
}

void klassKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
}

int klassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  Klass* k = Klass::cast(klassOop(obj));

  oop* const beg_oop = k->oop_block_beg();
  oop* const end_oop = k->oop_block_end();
  for (oop* cur_oop = beg_oop; cur_oop < end_oop; ++cur_oop) {
    PSParallelCompact::adjust_pointer(cur_oop);
  }

  return oop_size(obj);
}

int klassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
                                    HeapWord* beg_addr, HeapWord* end_addr) {
  Klass* k = Klass::cast(klassOop(obj));

  oop* const beg_oop = MAX2((oop*)beg_addr, k->oop_block_beg());
  oop* const end_oop = MIN2((oop*)end_addr, k->oop_block_end());
  for (oop* cur_oop = beg_oop; cur_oop < end_oop; ++cur_oop) {
    PSParallelCompact::adjust_pointer(cur_oop);
  }

  return oop_size(obj);
}
#endif // SERIALGC


#ifndef PRODUCT

// Printing

void klassKlass::oop_print_on(oop obj, outputStream* st) {
  Klass::oop_print_on(obj, st);
}


void klassKlass::oop_print_value_on(oop obj, outputStream* st) {
  Klass::oop_print_value_on(obj, st);
}

#endif

const char* klassKlass::internal_name() const {
  return "{other class}";
}


// Verification

void klassKlass::oop_verify_on(oop obj, outputStream* st) {
  Klass::oop_verify_on(obj, st);
  guarantee(obj->is_perm(),                      "should be in permspace");
  guarantee(obj->is_klass(),                     "should be klass");

  Klass* k = Klass::cast(klassOop(obj));
  if (k->super() != NULL) {
    guarantee(k->super()->is_perm(),             "should be in permspace");
    guarantee(k->super()->is_klass(),            "should be klass");
  }
  klassOop ko = k->secondary_super_cache();
  if( ko != NULL ) {
    guarantee(ko->is_perm(),                     "should be in permspace");
    guarantee(ko->is_klass(),                    "should be klass");
  }
  for( uint i = 0; i < primary_super_limit(); i++ ) {
    oop ko = k->adr_primary_supers()[i]; // Cannot use normal accessor because it asserts
    if( ko != NULL ) {
      guarantee(ko->is_perm(),                   "should be in permspace");
      guarantee(ko->is_klass(),                  "should be klass");
    }
  }

  if (k->java_mirror() != NULL || (k->oop_is_instance() && instanceKlass::cast(klassOop(obj))->is_loaded())) {
    guarantee(k->java_mirror() != NULL,          "should be allocated");
    guarantee(k->java_mirror()->is_perm(),       "should be in permspace");
    guarantee(k->java_mirror()->is_instance(),   "should be instance");
  }
  if (k->name() != NULL) {
    guarantee(Universe::heap()->is_in_permanent(k->name()),
              "should be in permspace");
    guarantee(k->name()->is_symbol(), "should be symbol");
  }
}