view src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp @ 3979:4dfb2df418f2

6484982: G1: process references during evacuation pauses Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate. Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp
author johnc
date Thu, 22 Sep 2011 10:57:37 -0700
parents e1162778c1c8
children f08d439fab8c
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/*
 * Copyright (c) 2001, 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/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/heapRegion.hpp"
#include "gc_implementation/g1/satbQueue.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/thread.hpp"
#ifdef TARGET_OS_FAMILY_linux
# include "thread_linux.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "thread_solaris.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "thread_windows.inline.hpp"
#endif

G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
                                                 int max_covered_regions) :
    CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
{
  _kind = G1SATBCT;
}


void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
  // Nulls should have been already filtered.
  assert(pre_val->is_oop(true), "Error");

  if (!JavaThread::satb_mark_queue_set().is_active()) return;
  Thread* thr = Thread::current();
  if (thr->is_Java_thread()) {
    JavaThread* jt = (JavaThread*)thr;
    jt->satb_mark_queue().enqueue(pre_val);
  } else {
    MutexLocker x(Shared_SATB_Q_lock);
    JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
  }
}

template <class T> void
G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
  if (!JavaThread::satb_mark_queue_set().is_active()) return;
  T* elem_ptr = dst;
  for (int i = 0; i < count; i++, elem_ptr++) {
    T heap_oop = oopDesc::load_heap_oop(elem_ptr);
    if (!oopDesc::is_null(heap_oop)) {
      enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
    }
  }
}

G1SATBCardTableLoggingModRefBS::
G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
                               int max_covered_regions) :
  G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
  _dcqs(JavaThread::dirty_card_queue_set())
{
  _kind = G1SATBCTLogging;
}

void
G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
                                                     oop new_val) {
  jbyte* byte = byte_for(field);
  if (*byte != dirty_card) {
    *byte = dirty_card;
    Thread* thr = Thread::current();
    if (thr->is_Java_thread()) {
      JavaThread* jt = (JavaThread*)thr;
      jt->dirty_card_queue().enqueue(byte);
    } else {
      MutexLockerEx x(Shared_DirtyCardQ_lock,
                      Mutex::_no_safepoint_check_flag);
      _dcqs.shared_dirty_card_queue()->enqueue(byte);
    }
  }
}

void
G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
                                                       oop new_val) {
  uintptr_t field_uint = (uintptr_t)field;
  uintptr_t new_val_uint = (uintptr_t)new_val;
  uintptr_t comb = field_uint ^ new_val_uint;
  comb = comb >> HeapRegion::LogOfHRGrainBytes;
  if (comb == 0) return;
  if (new_val == NULL) return;
  // Otherwise, log it.
  G1SATBCardTableLoggingModRefBS* g1_bs =
    (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
  g1_bs->write_ref_field_work(field, new_val);
}

void
G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
  jbyte* byte = byte_for(mr.start());
  jbyte* last_byte = byte_for(mr.last());
  Thread* thr = Thread::current();
  if (whole_heap) {
    while (byte <= last_byte) {
      *byte = dirty_card;
      byte++;
    }
  } else {
    // Enqueue if necessary.
    if (thr->is_Java_thread()) {
      JavaThread* jt = (JavaThread*)thr;
      while (byte <= last_byte) {
        if (*byte != dirty_card) {
          *byte = dirty_card;
          jt->dirty_card_queue().enqueue(byte);
        }
        byte++;
      }
    } else {
      MutexLockerEx x(Shared_DirtyCardQ_lock,
                      Mutex::_no_safepoint_check_flag);
      while (byte <= last_byte) {
        if (*byte != dirty_card) {
          *byte = dirty_card;
          _dcqs.shared_dirty_card_queue()->enqueue(byte);
        }
        byte++;
      }
    }
  }
}