src/hotspot/share/gc/shared/scavengableNMethods.hpp

/*
 * Copyright (c) 2019, 2023, 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.
 *
 */

#ifndef SHARE_GC_SHARED_SCAVENGABLENMETHODS_HPP
#define SHARE_GC_SHARED_SCAVENGABLENMETHODS_HPP

#include "memory/allStatic.hpp"
#include "utilities/macros.hpp"

class BoolObjectClosure;
class CodeBlobClosure;
class CodeBlobToOopClosure;
class nmethod;

class ScavengableNMethods : public AllStatic {
  friend class VMStructs;

  static nmethod*           _head;
  static BoolObjectClosure* _is_scavengable;

public:
  static void initialize(BoolObjectClosure* is_scavengable);

  static void register_nmethod(nmethod* nm);
  static void unregister_nmethod(nmethod* nm);
  static void verify_nmethod(nmethod* nm);

  // Remove nmethods that no longer have oops into young gen.
  static void prune_nmethods_not_into_young();
  // Remvoe unlinked (dead) nmethods.
  static void prune_unlinked_nmethods();

  // Apply closure to every scavengable nmethod.
  // Remove nmethods that no longer have scavengable oops.
  static void nmethods_do(CodeBlobToOopClosure* cl);

  static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* cl) PRODUCT_RETURN;

private:
  static void nmethods_do_and_prune(CodeBlobToOopClosure* cl);
  static void unlist_nmethod(nmethod* nm, nmethod* prev);

  static bool has_scavengable_oops(nmethod* nm);

  static void mark_on_list_nmethods() PRODUCT_RETURN;
  static void verify_unlisted_nmethods(CodeBlobClosure* cl) PRODUCT_RETURN;
};

#endif // SHARE_GC_SHARED_SCAVENGABLENMETHODS_HPP