/*

 * Copyright (c) 2014, 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_IMPLEMENTATION_G1_G1ALLOCATOR_HPP

#define SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP

#include "gc_implementation/g1/g1AllocationContext.hpp"

#include "gc_implementation/g1/g1AllocRegion.hpp"

#include "gc_implementation/shared/parGCAllocBuffer.hpp"

enum GCAllocPurpose {

  GCAllocForTenured,

  GCAllocForSurvived,

  GCAllocPurposeCount

};

// Base class for G1 allocators.

class G1Allocator : public CHeapObj<mtGC> {

  friend class VMStructs;

protected:

  G1CollectedHeap* _g1h;

  // Outside of GC pauses, the number of bytes used in all regions other

  // than the current allocation region.

  size_t _summary_bytes_used;

public:

   G1Allocator(G1CollectedHeap* heap) :

     _g1h(heap), _summary_bytes_used(0) { }

   static G1Allocator* create_allocator(G1CollectedHeap* g1h);

   virtual void init_mutator_alloc_region() = 0;

   virtual void release_mutator_alloc_region() = 0;

   virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info) = 0;

   virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) = 0;

   virtual void abandon_gc_alloc_regions() = 0;

   virtual MutatorAllocRegion*    mutator_alloc_region(AllocationContext_t context) = 0;

   virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) = 0;

   virtual OldGCAllocRegion*      old_gc_alloc_region(AllocationContext_t context) = 0;

   virtual size_t                 used() = 0;

   virtual bool                   is_retained_old_region(HeapRegion* hr) = 0;

   void                           reuse_retained_old_region(EvacuationInfo& evacuation_info,

                                                            OldGCAllocRegion* old,

                                                            HeapRegion** retained);

   size_t used_unlocked() const {

     return _summary_bytes_used;

   }

   void increase_used(size_t bytes) {

     _summary_bytes_used += bytes;

   }

   void decrease_used(size_t bytes) {

     assert(_summary_bytes_used >= bytes,

            err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" should be >= bytes: "SIZE_FORMAT,

                _summary_bytes_used, bytes));

     _summary_bytes_used -= bytes;

   }

   void set_used(size_t bytes) {

     _summary_bytes_used = bytes;

   }

};

// The default allocator for G1.

class G1DefaultAllocator : public G1Allocator {

protected:

  // Alloc region used to satisfy mutator allocation requests.

  MutatorAllocRegion _mutator_alloc_region;

  // Alloc region used to satisfy allocation requests by the GC for

  // survivor objects.

  SurvivorGCAllocRegion _survivor_gc_alloc_region;

  // Alloc region used to satisfy allocation requests by the GC for

  // old objects.

  OldGCAllocRegion _old_gc_alloc_region;

  HeapRegion* _retained_old_gc_alloc_region;

public:

  G1DefaultAllocator(G1CollectedHeap* heap) : G1Allocator(heap), _retained_old_gc_alloc_region(NULL) { }

  virtual void init_mutator_alloc_region();

  virtual void release_mutator_alloc_region();

  virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info);

  virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info);

  virtual void abandon_gc_alloc_regions();

  virtual bool is_retained_old_region(HeapRegion* hr) {

    return _retained_old_gc_alloc_region == hr;

  }

  virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) {

    return &_mutator_alloc_region;

  }

  virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) {

    return &_survivor_gc_alloc_region;

  }

  virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) {

    return &_old_gc_alloc_region;

  }

  virtual size_t used() {

    assert(Heap_lock->owner() != NULL,

           "Should be owned on this thread's behalf.");

    size_t result = _summary_bytes_used;

    // Read only once in case it is set to NULL concurrently

    HeapRegion* hr = mutator_alloc_region(AllocationContext::current())->get();

    if (hr != NULL) {

      result += hr->used();

    }

    return result;

  }

};

class G1ParGCAllocBuffer: public ParGCAllocBuffer {

private:

  bool _retired;

public:

  G1ParGCAllocBuffer(size_t gclab_word_size);

  virtual ~G1ParGCAllocBuffer() {

    guarantee(_retired, "Allocation buffer has not been retired");

  }

  virtual void set_buf(HeapWord* buf) {

    ParGCAllocBuffer::set_buf(buf);

    _retired = false;

  }

  virtual void retire(bool end_of_gc, bool retain) {

    if (_retired) {

      return;

    }

    ParGCAllocBuffer::retire(end_of_gc, retain);

    _retired = true;

  }

};

class G1ParGCAllocator : public CHeapObj<mtGC> {

  friend class G1ParScanThreadState;

protected:

  G1CollectedHeap* _g1h;

  size_t _alloc_buffer_waste;

  size_t _undo_waste;

  void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }

  void add_to_undo_waste(size_t waste)         { _undo_waste += waste; }

  HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context);

  virtual void retire_alloc_buffers() = 0;

  virtual G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose, AllocationContext_t context) = 0;

public:

  G1ParGCAllocator(G1CollectedHeap* g1h) :

    _g1h(g1h), _alloc_buffer_waste(0), _undo_waste(0) {

  }

  static G1ParGCAllocator* create_allocator(G1CollectedHeap* g1h);

  size_t alloc_buffer_waste() { return _alloc_buffer_waste; }

  size_t undo_waste() {return _undo_waste; }

  HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) {

    HeapWord* obj = NULL;

    if (purpose == GCAllocForSurvived) {

      obj = alloc_buffer(purpose, context)->allocate_aligned(word_sz, SurvivorAlignmentInBytes);

    } else {

      obj = alloc_buffer(purpose, context)->allocate(word_sz);

    }

    if (obj != NULL) {

      return obj;

    }

    return allocate_slow(purpose, word_sz, context);

  }

  void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz, AllocationContext_t context) {

    if (alloc_buffer(purpose, context)->contains(obj)) {

      assert(alloc_buffer(purpose, context)->contains(obj + word_sz - 1),

             "should contain whole object");

      alloc_buffer(purpose, context)->undo_allocation(obj, word_sz);

    } else {

      CollectedHeap::fill_with_object(obj, word_sz);

      add_to_undo_waste(word_sz);

    }

  }

};

class G1DefaultParGCAllocator : public G1ParGCAllocator {

  G1ParGCAllocBuffer  _surviving_alloc_buffer;

  G1ParGCAllocBuffer  _tenured_alloc_buffer;

  G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];

public:

  G1DefaultParGCAllocator(G1CollectedHeap* g1h);

  virtual G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose, AllocationContext_t context) {

    return _alloc_buffers[purpose];

  }

  virtual void retire_alloc_buffers() ;

};

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP