view src/share/vm/gc_implementation/g1/heapRegionSets.cpp @ 2539:e8b0b0392037

7046182: G1: remove unnecessary iterations over the collection set Summary: Remove two unnecessary iterations over the collection set which are supposed to prepare the RSet's of the CSet regions for parallel iterations (we'll make sure this is done incrementally). I'll piggyback on this CR the removal of the G1_REM_SET_LOGGING code. Reviewed-by: brutisso, johnc
author tonyp
date Tue, 21 Jun 2011 15:23:07 -0400
parents 1216415d8e35
children 8aae2050e83e
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/*
 * Copyright (c) 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 "gc_implementation/g1/heapRegionRemSet.hpp"
#include "gc_implementation/g1/heapRegionSets.hpp"

//////////////////// FreeRegionList ////////////////////

const char* FreeRegionList::verify_region_extra(HeapRegion* hr) {
  if (hr->is_young()) {
    return "the region should not be young";
  }
  // The superclass will check that the region is empty and
  // not-humongous.
  return HeapRegionLinkedList::verify_region_extra(hr);
}

//////////////////// MasterFreeRegionList ////////////////////

const char* MasterFreeRegionList::verify_region_extra(HeapRegion* hr) {
  // We should reset the RSet for parallel iteration before we add it
  // to the master free list so that it is ready when the region is
  // re-allocated.
  if (!hr->rem_set()->verify_ready_for_par_iteration()) {
    return "the region's RSet should be ready for parallel iteration";
  }
  return FreeRegionList::verify_region_extra(hr);
}

bool MasterFreeRegionList::check_mt_safety() {
  // Master Free List MT safety protocol:
  // (a) If we're at a safepoint, operations on the master free list
  // should be invoked by either the VM thread (which will serialize
  // them) or by the GC workers while holding the
  // FreeList_lock.
  // (b) If we're not at a safepoint, operations on the master free
  // list should be invoked while holding the Heap_lock.

  guarantee((SafepointSynchronize::is_at_safepoint() &&
               (Thread::current()->is_VM_thread() ||
                                            FreeList_lock->owned_by_self())) ||
            (!SafepointSynchronize::is_at_safepoint() &&
                                                Heap_lock->owned_by_self()),
            hrs_ext_msg(this, "master free list MT safety protocol"));

  return FreeRegionList::check_mt_safety();
}

//////////////////// SecondaryFreeRegionList ////////////////////

bool SecondaryFreeRegionList::check_mt_safety() {
  // Secondary Free List MT safety protocol:
  // Operations on the secondary free list should always be invoked
  // while holding the SecondaryFreeList_lock.

  guarantee(SecondaryFreeList_lock->owned_by_self(),
            hrs_ext_msg(this, "secondary free list MT safety protocol"));

  return FreeRegionList::check_mt_safety();
}

//////////////////// HumongousRegionSet ////////////////////

const char* HumongousRegionSet::verify_region_extra(HeapRegion* hr) {
  if (hr->is_young()) {
    return "the region should not be young";
  }
  // The superclass will check that the region is not empty and
  // humongous.
  return HeapRegionSet::verify_region_extra(hr);
}

//////////////////// MasterHumongousRegionSet ////////////////////

bool MasterHumongousRegionSet::check_mt_safety() {
  // Master Humongous Set MT safety protocol:
  // (a) If we're at a safepoint, operations on the master humongous
  // set should be invoked by either the VM thread (which will
  // serialize them) or by the GC workers while holding the
  // OldSets_lock.
  // (b) If we're not at a safepoint, operations on the master
  // humongous set should be invoked while holding the Heap_lock.

  guarantee((SafepointSynchronize::is_at_safepoint() &&
               (Thread::current()->is_VM_thread() ||
                                             OldSets_lock->owned_by_self())) ||
            (!SafepointSynchronize::is_at_safepoint() &&
                                                 Heap_lock->owned_by_self()),
            hrs_ext_msg(this, "master humongous set MT safety protocol"));
  return HumongousRegionSet::check_mt_safety();
}