view src/share/vm/memory/iterator.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 da91efe96a93
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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 "memory/iterator.hpp"
#include "oops/oop.inline.hpp"

#ifdef ASSERT
bool OopClosure::_must_remember_klasses = false;
#endif

void ObjectToOopClosure::do_object(oop obj) {
  obj->oop_iterate(_cl);
}

void VoidClosure::do_void() {
  ShouldNotCallThis();
}

#ifdef ASSERT
bool OopClosure::must_remember_klasses() {
  return _must_remember_klasses;
}
void OopClosure::set_must_remember_klasses(bool v) {
  _must_remember_klasses = v;
}
#endif


MarkingCodeBlobClosure::MarkScope::MarkScope(bool activate)
  : _active(activate)
{
  if (_active)  nmethod::oops_do_marking_prologue();
}

MarkingCodeBlobClosure::MarkScope::~MarkScope() {
  if (_active)  nmethod::oops_do_marking_epilogue();
}

void MarkingCodeBlobClosure::do_code_blob(CodeBlob* cb) {
  nmethod* nm = cb->as_nmethod_or_null();
  if (nm == NULL)  return;
  if (!nm->test_set_oops_do_mark()) {
    NOT_PRODUCT(if (TraceScavenge)  nm->print_on(tty, "oops_do, 1st visit\n"));
    do_newly_marked_nmethod(nm);
  } else {
    NOT_PRODUCT(if (TraceScavenge)  nm->print_on(tty, "oops_do, skipped on 2nd visit\n"));
  }
}

void CodeBlobToOopClosure::do_newly_marked_nmethod(nmethod* nm) {
  nm->oops_do(_cl, /*do_strong_roots_only=*/ true);
}

void CodeBlobToOopClosure::do_code_blob(CodeBlob* cb) {
  if (!_do_marking) {
    nmethod* nm = cb->as_nmethod_or_null();
    NOT_PRODUCT(if (TraceScavenge && Verbose && nm != NULL)  nm->print_on(tty, "oops_do, unmarked visit\n"));
    // This assert won't work, since there are lots of mini-passes
    // (mostly in debug mode) that co-exist with marking phases.
    //assert(!(cb->is_nmethod() && ((nmethod*)cb)->test_oops_do_mark()), "found marked nmethod during mark-free phase");
    if (nm != NULL) {
      nm->oops_do(_cl);
    }
  } else {
    MarkingCodeBlobClosure::do_code_blob(cb);
  }
}