/*

 * Copyright (c) 2015, 2017, 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_VM_GC_G1_G1ROOTPROCESSOR_HPP

#define SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP

#include "gc/shared/strongRootsScope.hpp"

#include "memory/allocation.hpp"

#include "runtime/mutex.hpp"

class CLDClosure;

class CodeBlobClosure;

class G1CollectedHeap;

class G1EvacuationRootClosures;

class G1GCPhaseTimes;

class G1RootClosures;

class Monitor;

class OopClosure;

class SubTasksDone;

// Scoped object to assist in applying oop, CLD and code blob closures to

// root locations. Handles claiming of different root scanning tasks

// and takes care of global state for root scanning via a StrongRootsScope.

// In the parallel case there is a shared G1RootProcessor object where all

// worker thread call the process_roots methods.

class G1RootProcessor : public StackObj {

  G1CollectedHeap* _g1h;

  SubTasksDone _process_strong_tasks;

  StrongRootsScope _srs;

  // Used to implement the Thread work barrier.

  Monitor _lock;

  volatile jint _n_workers_discovered_strong_classes;

  enum G1H_process_roots_tasks {

    G1RP_PS_Universe_oops_do,

    G1RP_PS_JNIHandles_oops_do,

    G1RP_PS_ObjectSynchronizer_oops_do,

    G1RP_PS_Management_oops_do,

    G1RP_PS_SystemDictionary_oops_do,

    G1RP_PS_ClassLoaderDataGraph_oops_do,

    G1RP_PS_jvmti_oops_do,

    G1RP_PS_CodeCache_oops_do,

    G1RP_PS_aot_oops_do,

    G1RP_PS_filter_satb_buffers,

    G1RP_PS_refProcessor_oops_do,

    // Leave this one last.

    G1RP_PS_NumElements

  };

  void worker_has_discovered_all_strong_classes();

  void wait_until_all_strong_classes_discovered();

  void process_all_roots(OopClosure* oops,

                         CLDClosure* clds,

                         CodeBlobClosure* blobs,

                         bool process_string_table);

  void process_java_roots(G1RootClosures* closures,

                          G1GCPhaseTimes* phase_times,

                          uint worker_i);

  void process_vm_roots(G1RootClosures* closures,

                        G1GCPhaseTimes* phase_times,

                        uint worker_i);

  void process_string_table_roots(G1RootClosures* closures,

                                  G1GCPhaseTimes* phase_times,

                                  uint worker_i);

  void process_code_cache_roots(CodeBlobClosure* code_closure,

                                G1GCPhaseTimes* phase_times,

                                uint worker_i);

public:

  G1RootProcessor(G1CollectedHeap* g1h, uint n_workers);

  // Apply closures to the strongly and weakly reachable roots in the system

  // in a single pass.

  // Record and report timing measurements for sub phases using the worker_i

  void evacuate_roots(G1EvacuationRootClosures* closures, uint worker_i);

  // Apply oops, clds and blobs to all strongly reachable roots in the system

  void process_strong_roots(OopClosure* oops,

                            CLDClosure* clds,

                            CodeBlobClosure* blobs);

  // Apply oops, clds and blobs to strongly and weakly reachable roots in the system

  void process_all_roots(OopClosure* oops,

                         CLDClosure* clds,

                         CodeBlobClosure* blobs);

  // Apply oops, clds and blobs to strongly and weakly reachable roots in the system,

  // the only thing different from process_all_roots is that we skip the string table

  // to avoid keeping every string live when doing class unloading.

  void process_all_roots_no_string_table(OopClosure* oops,

                                         CLDClosure* clds,

                                         CodeBlobClosure* blobs);

  // Number of worker threads used by the root processor.

  uint n_workers() const;

};

#endif // SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP