view src/share/vm/gc_implementation/g1/satbQueue.cpp @ 889:15c5903cf9e1

6865703: G1: Parallelize hot card cache cleanup Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads. Reviewed-by: jmasa, tonyp
author johnc
date Mon, 03 Aug 2009 12:59:30 -0700
parents df6caf649ff7
children 44f61c24ddab
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.
 *
 */

# include "incls/_precompiled.incl"
# include "incls/_satbQueue.cpp.incl"

void ObjPtrQueue::apply_closure(ObjectClosure* cl) {
  if (_buf != NULL) {
    apply_closure_to_buffer(cl, _buf, _index, _sz);
    _index = _sz;
  }
}

void ObjPtrQueue::apply_closure_to_buffer(ObjectClosure* cl,
                                          void** buf, size_t index, size_t sz) {
  if (cl == NULL) return;
  for (size_t i = index; i < sz; i += oopSize) {
    oop obj = (oop)buf[byte_index_to_index((int)i)];
    // There can be NULL entries because of destructors.
    if (obj != NULL) {
      cl->do_object(obj);
    }
  }
}

#ifdef ASSERT
void ObjPtrQueue::verify_oops_in_buffer() {
  if (_buf == NULL) return;
  for (size_t i = _index; i < _sz; i += oopSize) {
    oop obj = (oop)_buf[byte_index_to_index((int)i)];
    assert(obj != NULL && obj->is_oop(true /* ignore mark word */),
           "Not an oop");
  }
}
#endif

#ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
#pragma warning( disable:4355 ) // 'this' : used in base member initializer list
#endif // _MSC_VER


SATBMarkQueueSet::SATBMarkQueueSet() :
  PtrQueueSet(),
  _closure(NULL), _par_closures(NULL),
  _shared_satb_queue(this, true /*perm*/)
{}

void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
                                  int max_completed_queue,
                                  Mutex* lock) {
  PtrQueueSet::initialize(cbl_mon, fl_lock, max_completed_queue);
  _shared_satb_queue.set_lock(lock);
  if (ParallelGCThreads > 0) {
    _par_closures = NEW_C_HEAP_ARRAY(ObjectClosure*, ParallelGCThreads);
  }
}


void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) {
  DEBUG_ONLY(t->satb_mark_queue().verify_oops_in_buffer();)
  t->satb_mark_queue().handle_zero_index();
}

void SATBMarkQueueSet::set_active_all_threads(bool b) {
  _all_active = b;
  for(JavaThread* t = Threads::first(); t; t = t->next()) {
    t->satb_mark_queue().set_active(b);
  }
}

void SATBMarkQueueSet::set_closure(ObjectClosure* closure) {
  _closure = closure;
}

void SATBMarkQueueSet::set_par_closure(int i, ObjectClosure* par_closure) {
  assert(ParallelGCThreads > 0 && _par_closures != NULL, "Precondition");
  _par_closures[i] = par_closure;
}

void SATBMarkQueueSet::iterate_closure_all_threads() {
  for(JavaThread* t = Threads::first(); t; t = t->next()) {
    t->satb_mark_queue().apply_closure(_closure);
  }
  shared_satb_queue()->apply_closure(_closure);
}

void SATBMarkQueueSet::par_iterate_closure_all_threads(int worker) {
  SharedHeap* sh = SharedHeap::heap();
  int parity = sh->strong_roots_parity();

  for(JavaThread* t = Threads::first(); t; t = t->next()) {
    if (t->claim_oops_do(true, parity)) {
      t->satb_mark_queue().apply_closure(_par_closures[worker]);
    }
  }
  // We'll have worker 0 do this one.
  if (worker == 0) {
    shared_satb_queue()->apply_closure(_par_closures[0]);
  }
}

bool SATBMarkQueueSet::apply_closure_to_completed_buffer_work(bool par,
                                                              int worker) {
  CompletedBufferNode* nd = NULL;
  {
    MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
    if (_completed_buffers_head != NULL) {
      nd = _completed_buffers_head;
      _completed_buffers_head = nd->next;
      if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
      _n_completed_buffers--;
      if (_n_completed_buffers == 0) _process_completed = false;
    }
  }
  ObjectClosure* cl = (par ? _par_closures[worker] : _closure);
  if (nd != NULL) {
    ObjPtrQueue::apply_closure_to_buffer(cl, nd->buf, 0, _sz);
    deallocate_buffer(nd->buf);
    delete nd;
    return true;
  } else {
    return false;
  }
}

void SATBMarkQueueSet::abandon_partial_marking() {
  CompletedBufferNode* buffers_to_delete = NULL;
  {
    MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
    while (_completed_buffers_head != NULL) {
      CompletedBufferNode* nd = _completed_buffers_head;
      _completed_buffers_head = nd->next;
      nd->next = buffers_to_delete;
      buffers_to_delete = nd;
    }
    _completed_buffers_tail = NULL;
    _n_completed_buffers = 0;
    DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
  }
  while (buffers_to_delete != NULL) {
    CompletedBufferNode* nd = buffers_to_delete;
    buffers_to_delete = nd->next;
    deallocate_buffer(nd->buf);
    delete nd;
  }
  assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
  // So we can safely manipulate these queues.
  for (JavaThread* t = Threads::first(); t; t = t->next()) {
    t->satb_mark_queue().reset();
  }
  shared_satb_queue()->reset();
}