view src/share/vm/oops/objArrayKlassKlass.cpp @ 2149:7e37af9d69ef

7011379: G1: overly long concurrent marking cycles Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads. Reviewed-by: johnc, ysr
author tonyp
date Wed, 19 Jan 2011 09:35:17 -0500
parents f95d63e2154a
children 3582bf76420e
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/*
 * 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/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"

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 (except for symbol arrays, since symbolKlass
  // does not have a name).  This will potentially allocate an object, cause
  // GC, and all other kinds of things.  Hence, this must be done before we
  // get a handle to the new objArrayKlass we want to construct.  We cannot
  // block while holding a handling to a partly initialized object.
  symbolHandle name = symbolHandle();

  if (!element_klass->oop_is_symbol()) {
    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 = oopFactory::new_symbol_handle(new_str, CHECK_0);
  }

  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());

  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(obj, blk);
}

#ifndef SERIALGC
void objArrayKlassKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  assert(obj->blueprint()->oop_is_objArrayKlass(),"must be an obj array klass");
}

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);
}

int objArrayKlassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
                                            HeapWord* beg_addr,
                                            HeapWord* end_addr) {
  assert(obj->is_klass(), "must be klass");
  assert(klassOop(obj)->klass_part()->oop_is_objArray_slow(), "must be obj array");

  oop* p;
  objArrayKlass* oak = objArrayKlass::cast((klassOop)obj);
  p = oak->element_klass_addr();
  PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
  p = oak->bottom_klass_addr();
  PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);

  return arrayKlassKlass::oop_update_pointers(cm, obj, beg_addr, end_addr);
}
#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) {
  klassKlass::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");
}