/*

 * Copyright (c) 2017, 2019, 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_SHENANDOAHCODEROOTS_HPP

#define SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP

#include "code/codeCache.hpp"

#include "gc/shenandoah/shenandoahSharedVariables.hpp"

#include "gc/shenandoah/shenandoahLock.hpp"

#include "memory/allocation.hpp"

#include "memory/iterator.hpp"

class ShenandoahHeap;

class ShenandoahHeapRegion;

class ShenandoahParallelCodeHeapIterator {

  friend class CodeCache;

private:

  CodeHeap*     _heap;

  DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile int));

  volatile int  _claimed_idx;

  volatile bool _finished;

  DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);

public:

  ShenandoahParallelCodeHeapIterator(CodeHeap* heap);

  void parallel_blobs_do(CodeBlobClosure* f);

};

class ShenandoahParallelCodeCacheIterator {

  friend class CodeCache;

private:

  ShenandoahParallelCodeHeapIterator* _iters;

  int                       _length;

private:

  // Noncopyable.

  ShenandoahParallelCodeCacheIterator(const ShenandoahParallelCodeCacheIterator& o);

  ShenandoahParallelCodeCacheIterator& operator=(const ShenandoahParallelCodeCacheIterator& o);

public:

  ShenandoahParallelCodeCacheIterator(const GrowableArray<CodeHeap*>* heaps);

  ~ShenandoahParallelCodeCacheIterator();

  void parallel_blobs_do(CodeBlobClosure* f);

};

// ShenandoahNMethod tuple records the internal locations of oop slots within the nmethod.

// This allows us to quickly scan the oops without doing the nmethod-internal scans, that

// sometimes involves parsing the machine code. Note it does not record the oops themselves,

// because it would then require handling these tuples as the new class of roots.

class ShenandoahNMethod : public CHeapObj<mtGC> {

private:

  nmethod* _nm;

  oop**    _oops;

  int      _oops_count;

public:

  ShenandoahNMethod(nmethod *nm, GrowableArray<oop*>* oops);

  ~ShenandoahNMethod();

  nmethod* nm() {

    return _nm;

  }

  bool has_cset_oops(ShenandoahHeap* heap);

  void assert_alive_and_correct() NOT_DEBUG_RETURN;

  void assert_same_oops(GrowableArray<oop*>* oops) NOT_DEBUG_RETURN;

  static bool find_with_nmethod(void* nm, ShenandoahNMethod* other) {

    return other->_nm == nm;

  }

};

class ShenandoahCodeRootsIterator {

  friend class ShenandoahCodeRoots;

protected:

  ShenandoahHeap* _heap;

  ShenandoahParallelCodeCacheIterator _par_iterator;

  ShenandoahSharedFlag _seq_claimed;

  DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));

  volatile size_t _claimed;

  DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);

protected:

  ShenandoahCodeRootsIterator();

  ~ShenandoahCodeRootsIterator();

  template<bool CSET_FILTER>

  void dispatch_parallel_blobs_do(CodeBlobClosure *f);

  template<bool CSET_FILTER>

  void fast_parallel_blobs_do(CodeBlobClosure *f);

};

class ShenandoahAllCodeRootsIterator : public ShenandoahCodeRootsIterator {

public:

  ShenandoahAllCodeRootsIterator() : ShenandoahCodeRootsIterator() {};

  void possibly_parallel_blobs_do(CodeBlobClosure *f);

};

class ShenandoahCsetCodeRootsIterator : public ShenandoahCodeRootsIterator {

public:

  ShenandoahCsetCodeRootsIterator() : ShenandoahCodeRootsIterator() {};

  void possibly_parallel_blobs_do(CodeBlobClosure* f);

};

class ShenandoahCodeRoots : public AllStatic {

  friend class ShenandoahHeap;

  friend class ShenandoahCodeRootsIterator;

public:

  static void initialize();

  static void add_nmethod(nmethod* nm);

  static void remove_nmethod(nmethod* nm);

private:

  static GrowableArray<ShenandoahNMethod*>* _recorded_nms;

  static ShenandoahLock                     _recorded_nms_lock;

};

#endif // SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP