/*

 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.

 *

 * 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_SHENANDOAH_SHENANDOAHVERIFIER_HPP

#define SHARE_GC_SHENANDOAH_SHENANDOAHVERIFIER_HPP

#include "gc/shared/markBitMap.hpp"

#include "gc/shenandoah/shenandoahRootVerifier.hpp"

#include "memory/allocation.hpp"

#include "oops/oopsHierarchy.hpp"

#include "utilities/stack.hpp"

class ShenandoahHeap;

#ifdef _WINDOWS

#pragma warning( disable : 4522 )

#endif

class ShenandoahVerifierTask {

public:

  ShenandoahVerifierTask(oop o = NULL, int idx = 0): _obj(o) { }

  ShenandoahVerifierTask(oop o, size_t idx): _obj(o) { }

  ShenandoahVerifierTask(const ShenandoahVerifierTask& t): _obj(t._obj) { }

  ShenandoahVerifierTask& operator =(const ShenandoahVerifierTask& t) {

    _obj = t._obj;

    return *this;

  }

  volatile ShenandoahVerifierTask&

  operator =(const volatile ShenandoahVerifierTask& t) volatile {

    (void)const_cast<oop&>(_obj = t._obj);

    return *this;

  }

  inline oop obj()  const { return _obj; }

private:

  oop _obj;

};

typedef Stack<ShenandoahVerifierTask, mtGC> ShenandoahVerifierStack;

typedef volatile juint ShenandoahLivenessData;

class ShenandoahVerifier : public CHeapObj<mtGC> {

private:

  ShenandoahHeap* _heap;

  MarkBitMap* _verification_bit_map;

public:

  typedef enum {

    // Disable marked objects verification.

    _verify_marked_disable,

    // Objects should be marked in "next" bitmap.

    _verify_marked_incomplete,

    // Objects should be marked in "complete" bitmap.

    _verify_marked_complete

  } VerifyMarked;

  typedef enum {

    // Disable forwarded objects verification.

    _verify_forwarded_disable,

    // Objects should not have forwardees.

    _verify_forwarded_none,

    // Objects may have forwardees.

    _verify_forwarded_allow

  } VerifyForwarded;

  typedef enum {

    // Disable collection set verification.

    _verify_cset_disable,

    // Should have no references to cset.

    _verify_cset_none,

    // May have references to cset, all should be forwarded.

    // Note: Allowing non-forwarded references to cset is equivalent

    // to _verify_cset_disable.

    _verify_cset_forwarded

  } VerifyCollectionSet;

  typedef enum {

    // Disable liveness verification

    _verify_liveness_disable,

    // All objects should belong to live regions

    _verify_liveness_conservative,

    // All objects should belong to live regions,

    // and liveness data should be accurate

    _verify_liveness_complete

  } VerifyLiveness;

  typedef enum {

    // Disable region verification

    _verify_regions_disable,

    // No trash regions allowed

    _verify_regions_notrash,

    // No collection set regions allowed

    _verify_regions_nocset,

    // No trash and no cset regions allowed

    _verify_regions_notrash_nocset

  } VerifyRegions;

  typedef enum {

    // Disable gc-state verification

    _verify_gcstate_disable,

    // Nothing is in progress, no forwarded objects

    _verify_gcstate_stable,

    // Nothing is in progress, some objects are forwarded

    _verify_gcstate_forwarded,

    // Evacuation is in progress, some objects are forwarded

    _verify_gcstate_evacuation

  } VerifyGCState;

  struct VerifyOptions {

    VerifyForwarded     _verify_forwarded;

    VerifyMarked        _verify_marked;

    VerifyCollectionSet _verify_cset;

    VerifyLiveness      _verify_liveness;

    VerifyRegions       _verify_regions;

    VerifyGCState       _verify_gcstate;

    VerifyOptions(VerifyForwarded verify_forwarded,

                  VerifyMarked verify_marked,

                  VerifyCollectionSet verify_collection_set,

                  VerifyLiveness verify_liveness,

                  VerifyRegions verify_regions,

                  VerifyGCState verify_gcstate) :

            _verify_forwarded(verify_forwarded), _verify_marked(verify_marked),

            _verify_cset(verify_collection_set),

            _verify_liveness(verify_liveness), _verify_regions(verify_regions),

            _verify_gcstate(verify_gcstate) {}

  };

private:

  void verify_at_safepoint(const char *label,

                           VerifyForwarded forwarded,

                           VerifyMarked marked,

                           VerifyCollectionSet cset,

                           VerifyLiveness liveness,

                           VerifyRegions regions,

                           VerifyGCState gcstate);

public:

  ShenandoahVerifier(ShenandoahHeap* heap, MarkBitMap* verification_bitmap) :

          _heap(heap), _verification_bit_map(verification_bitmap) {};

  void verify_before_concmark();

  void verify_after_concmark();

  void verify_before_evacuation();

  void verify_during_evacuation();

  void verify_after_evacuation();

  void verify_before_updaterefs();

  void verify_after_updaterefs();

  void verify_before_fullgc();

  void verify_after_fullgc();

  void verify_before_traversal();

  void verify_after_traversal();

  void verify_after_degenerated();

  void verify_generic(VerifyOption option);

  // Roots should only contain to-space oops

  void verify_roots_in_to_space();

  void verify_roots_no_forwarded();

  void verify_roots_no_forwarded_except(ShenandoahRootVerifier::RootTypes types);

};

#endif // SHARE_GC_SHENANDOAH_SHENANDOAHVERIFIER_HPP