view src/share/vm/oops/cpCacheKlass.cpp @ 452:00b023ae2d78

6722113: CMS: Incorrect overflow handling during precleaning of Reference lists Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery. Reviewed-by: apetrusenko, jcoomes
author ysr
date Thu, 20 Nov 2008 12:27:41 -0800
parents d1605aabd0a1
children 9a25e0c45327
line wrap: on
line source

/*
 * Copyright 1998-2008 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/_cpCacheKlass.cpp.incl"


int constantPoolCacheKlass::oop_size(oop obj) const {
  assert(obj->is_constantPoolCache(), "must be constantPool");
  return constantPoolCacheOop(obj)->object_size();
}


constantPoolCacheOop constantPoolCacheKlass::allocate(int length, TRAPS) {
  // allocate memory
  int size = constantPoolCacheOopDesc::object_size(length);
  KlassHandle klass (THREAD, as_klassOop());
  constantPoolCacheOop cache = (constantPoolCacheOop)
    CollectedHeap::permanent_obj_allocate(klass, size, CHECK_NULL);
  cache->set_length(length);
  cache->set_constant_pool(NULL);
  return cache;
}

klassOop constantPoolCacheKlass::create_klass(TRAPS) {
  constantPoolCacheKlass o;
  KlassHandle h_this_klass(THREAD, Universe::klassKlassObj());
  KlassHandle k = base_create_klass(h_this_klass, header_size(), o.vtbl_value(), CHECK_NULL);
  // Make sure size calculation is right
  assert(k()->size() == align_object_size(header_size()), "wrong size for object");
  java_lang_Class::create_mirror(k, CHECK_NULL); // Allocate mirror
  return k();
}


void constantPoolCacheKlass::oop_follow_contents(oop obj) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::constantPoolCacheKlassObj never moves.
  // gc of constant pool cache instance variables
  MarkSweep::mark_and_push((oop*)cache->constant_pool_addr());
  // gc of constant pool cache entries
  int i = cache->length();
  while (i-- > 0) cache->entry_at(i)->follow_contents();
}

#ifndef SERIALGC
void constantPoolCacheKlass::oop_follow_contents(ParCompactionManager* cm,
                                                 oop obj) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::constantPoolCacheKlassObj never moves.
  // gc of constant pool cache instance variables
  PSParallelCompact::mark_and_push(cm, (oop*)cache->constant_pool_addr());
  // gc of constant pool cache entries
  int i = cache->length();
  while (i-- > 0) cache->entry_at(i)->follow_contents(cm);
}
#endif // SERIALGC


int constantPoolCacheKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // Get size before changing pointers.
  // Don't call size() or oop_size() since that is a virtual call.
  int size = cache->object_size();
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::constantPoolCacheKlassObj never moves.
  // iteration over constant pool cache instance variables
  blk->do_oop((oop*)cache->constant_pool_addr());
  // iteration over constant pool cache entries
  for (int i = 0; i < cache->length(); i++) cache->entry_at(i)->oop_iterate(blk);
  return size;
}


int constantPoolCacheKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // Get size before changing pointers.
  // Don't call size() or oop_size() since that is a virtual call.
  int size = cache->object_size();
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::constantPoolCacheKlassObj never moves.
  // iteration over constant pool cache instance variables
  oop* addr = (oop*)cache->constant_pool_addr();
  if (mr.contains(addr)) blk->do_oop(addr);
  // iteration over constant pool cache entries
  for (int i = 0; i < cache->length(); i++) cache->entry_at(i)->oop_iterate_m(blk, mr);
  return size;
}


int constantPoolCacheKlass::oop_adjust_pointers(oop obj) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // Get size before changing pointers.
  // Don't call size() or oop_size() since that is a virtual call.
  int size = cache->object_size();
  // Performance tweak: We skip iterating over the klass pointer since we
  // know that Universe::constantPoolCacheKlassObj never moves.
  // Iteration over constant pool cache instance variables
  MarkSweep::adjust_pointer((oop*)cache->constant_pool_addr());
  // iteration over constant pool cache entries
  for (int i = 0; i < cache->length(); i++)
    cache->entry_at(i)->adjust_pointers();
  return size;
}

#ifndef SERIALGC
void constantPoolCacheKlass::oop_copy_contents(PSPromotionManager* pm,
                                               oop obj) {
  assert(obj->is_constantPoolCache(), "should be constant pool");
}

void constantPoolCacheKlass::oop_push_contents(PSPromotionManager* pm,
                                               oop obj) {
  assert(obj->is_constantPoolCache(), "should be constant pool");
}

int
constantPoolCacheKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;

  // Iteration over constant pool cache instance variables
  PSParallelCompact::adjust_pointer((oop*)cache->constant_pool_addr());

  // iteration over constant pool cache entries
  for (int i = 0; i < cache->length(); ++i) {
    cache->entry_at(i)->update_pointers();
  }

  return cache->object_size();
}

int
constantPoolCacheKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
                                            HeapWord* beg_addr,
                                            HeapWord* end_addr) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;

  // Iteration over constant pool cache instance variables
  oop* p;
  p = (oop*)cache->constant_pool_addr();
  PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);

  // Iteration over constant pool cache entries
  for (int i = 0; i < cache->length(); ++i) {
    cache->entry_at(i)->update_pointers(beg_addr, end_addr);
  }
  return cache->object_size();
}
#endif // SERIALGC

#ifndef PRODUCT

void constantPoolCacheKlass::oop_print_on(oop obj, outputStream* st) {
  assert(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // super print
  Klass::oop_print_on(obj, st);
  // print constant pool cache entries
  for (int i = 0; i < cache->length(); i++) cache->entry_at(i)->print(st, i);
}

#endif

void constantPoolCacheKlass::oop_verify_on(oop obj, outputStream* st) {
  guarantee(obj->is_constantPoolCache(), "obj must be constant pool cache");
  constantPoolCacheOop cache = (constantPoolCacheOop)obj;
  // super verify
  Klass::oop_verify_on(obj, st);
  // print constant pool cache entries
  for (int i = 0; i < cache->length(); i++) cache->entry_at(i)->verify(st);
}


const char* constantPoolCacheKlass::internal_name() const {
  return "{constant pool cache}";
}