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 /*

  * 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

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  */

 #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/g1/g1InCSetState.hpp"

 #include "gc_implementation/shared/parGCAllocBuffer.hpp"

 // 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;

    }

    virtual HeapRegion* new_heap_region(uint hrs_index,

                                        G1BlockOffsetSharedArray* sharedOffsetArray,

                                        MemRegion mr) {

      return new HeapRegion(hrs_index, sharedOffsetArray, mr);

    }

 };

 // 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;

   // The survivor alignment in effect in bytes.

   // == 0 : don't align survivors

   // != 0 : align survivors to that alignment

   // These values were chosen to favor the non-alignment case since some

   // architectures have a special compare against zero instructions.

   const uint _survivor_alignment_bytes;

   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; }

   virtual void retire_alloc_buffers() = 0;

   virtual G1ParGCAllocBuffer* alloc_buffer(InCSetState dest, AllocationContext_t context) = 0;

   // Calculate the survivor space object alignment in bytes. Returns that or 0 if

   // there are no restrictions on survivor alignment.

   static uint calc_survivor_alignment_bytes() {

     assert(SurvivorAlignmentInBytes >= ObjectAlignmentInBytes, "sanity");

     if (SurvivorAlignmentInBytes == ObjectAlignmentInBytes) {

       // No need to align objects in the survivors differently, return 0

       // which means "survivor alignment is not used".

       return 0;

     } else {

       assert(SurvivorAlignmentInBytes > 0, "sanity");

       return SurvivorAlignmentInBytes;

     }

   }

 public:

   G1ParGCAllocator(G1CollectedHeap* g1h) :

     _g1h(g1h), _survivor_alignment_bytes(calc_survivor_alignment_bytes()),

     _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; }

   // Allocate word_sz words in dest, either directly into the regions or by

   // allocating a new PLAB. Returns the address of the allocated memory, NULL if

   // not successful.

   HeapWord* allocate_direct_or_new_plab(InCSetState dest,

                                         size_t word_sz,

                                         AllocationContext_t context);

   // Allocate word_sz words in the PLAB of dest.  Returns the address of the

   // allocated memory, NULL if not successful.

   HeapWord* plab_allocate(InCSetState dest,

                           size_t word_sz,

                           AllocationContext_t context) {

     G1ParGCAllocBuffer* buffer = alloc_buffer(dest, context);

     if (_survivor_alignment_bytes == 0) {

       return buffer->allocate(word_sz);

     } else {

       return buffer->allocate_aligned(word_sz, _survivor_alignment_bytes);

     }

   }

   HeapWord* allocate(InCSetState dest, size_t word_sz,

                      AllocationContext_t context) {

     HeapWord* const obj = plab_allocate(dest, word_sz, context);

     if (obj != NULL) {

       return obj;

     }

     return allocate_direct_or_new_plab(dest, word_sz, context);

   }

   void undo_allocation(InCSetState dest, HeapWord* obj, size_t word_sz, AllocationContext_t context) {

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

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

              "should contain whole object");

       alloc_buffer(dest, 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[InCSetState::Num];

 public:

   G1DefaultParGCAllocator(G1CollectedHeap* g1h);

   virtual G1ParGCAllocBuffer* alloc_buffer(InCSetState dest, AllocationContext_t context) {

     assert(dest.is_valid(),

            err_msg("Allocation buffer index out-of-bounds: " CSETSTATE_FORMAT, dest.value()));

     assert(_alloc_buffers[dest.value()] != NULL,

            err_msg("Allocation buffer is NULL: " CSETSTATE_FORMAT, dest.value()));

     return _alloc_buffers[dest.value()];

   }

   virtual void retire_alloc_buffers() ;

 };

 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP