view src/share/vm/gc_implementation/g1/heapRegion.inline.hpp @ 890:6cb8e9df7174

6819077: G1: first GC thread coming late into the GC. Summary: The first worker thread is delayed when entering the GC because it clears the card count table that is used in identifying hot cards. Replace the card count table with a dynamically sized evicting hash table that includes an epoch based counter. Reviewed-by: iveresov, tonyp
author johnc
date Tue, 04 Aug 2009 16:00:17 -0700
parents
children c18cbe5936b8
line wrap: on
line source
/*
 * Copyright 2001-2007 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.
 *
 */

inline HeapWord* G1OffsetTableContigSpace::allocate(size_t size) {
  HeapWord* res = ContiguousSpace::allocate(size);
  if (res != NULL) {
    _offsets.alloc_block(res, size);
  }
  return res;
}

// Because of the requirement of keeping "_offsets" up to date with the
// allocations, we sequentialize these with a lock.  Therefore, best if
// this is used for larger LAB allocations only.
inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t size) {
  MutexLocker x(&_par_alloc_lock);
  // This ought to be just "allocate", because of the lock above, but that
  // ContiguousSpace::allocate asserts that either the allocating thread
  // holds the heap lock or it is the VM thread and we're at a safepoint.
  // The best I (dld) could figure was to put a field in ContiguousSpace
  // meaning "locking at safepoint taken care of", and set/reset that
  // here.  But this will do for now, especially in light of the comment
  // above.  Perhaps in the future some lock-free manner of keeping the
  // coordination.
  HeapWord* res = ContiguousSpace::par_allocate(size);
  if (res != NULL) {
    _offsets.alloc_block(res, size);
  }
  return res;
}

inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) {
  return _offsets.block_start(p);
}

inline HeapWord*
G1OffsetTableContigSpace::block_start_const(const void* p) const {
  return _offsets.block_start_const(p);
}