rev 7799 : imported patch 8073466-remove-ratining-functionality-in-pargcallocbuffer

   1 /*
   2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP
  27 
  28 #include "gc_implementation/g1/g1AllocationContext.hpp"
  29 #include "gc_implementation/g1/g1AllocRegion.hpp"
  30 #include "gc_implementation/g1/g1InCSetState.hpp"
  31 #include "gc_implementation/shared/parGCAllocBuffer.hpp"
  32 
  33 // Base class for G1 allocators.
  34 class G1Allocator : public CHeapObj<mtGC> {
  35   friend class VMStructs;
  36 protected:
  37   G1CollectedHeap* _g1h;
  38 
  39   // Outside of GC pauses, the number of bytes used in all regions other
  40   // than the current allocation region.
  41   size_t _summary_bytes_used;
  42 
  43 public:
  44    G1Allocator(G1CollectedHeap* heap) :
  45      _g1h(heap), _summary_bytes_used(0) { }
  46 
  47    static G1Allocator* create_allocator(G1CollectedHeap* g1h);
  48 
  49    virtual void init_mutator_alloc_region() = 0;
  50    virtual void release_mutator_alloc_region() = 0;
  51 
  52    virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info) = 0;
  53    virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) = 0;
  54    virtual void abandon_gc_alloc_regions() = 0;
  55 
  56    virtual MutatorAllocRegion*    mutator_alloc_region(AllocationContext_t context) = 0;
  57    virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) = 0;
  58    virtual OldGCAllocRegion*      old_gc_alloc_region(AllocationContext_t context) = 0;
  59    virtual size_t                 used() = 0;
  60    virtual bool                   is_retained_old_region(HeapRegion* hr) = 0;
  61 
  62    void                           reuse_retained_old_region(EvacuationInfo& evacuation_info,
  63                                                             OldGCAllocRegion* old,
  64                                                             HeapRegion** retained);
  65 
  66    size_t used_unlocked() const {
  67      return _summary_bytes_used;
  68    }
  69 
  70    void increase_used(size_t bytes) {
  71      _summary_bytes_used += bytes;
  72    }
  73 
  74    void decrease_used(size_t bytes) {
  75      assert(_summary_bytes_used >= bytes,
  76             err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" should be >= bytes: "SIZE_FORMAT,
  77                 _summary_bytes_used, bytes));
  78      _summary_bytes_used -= bytes;
  79    }
  80 
  81    void set_used(size_t bytes) {
  82      _summary_bytes_used = bytes;
  83    }
  84 
  85    virtual HeapRegion* new_heap_region(uint hrs_index,
  86                                        G1BlockOffsetSharedArray* sharedOffsetArray,
  87                                        MemRegion mr) {
  88      return new HeapRegion(hrs_index, sharedOffsetArray, mr);
  89    }
  90 };
  91 
  92 // The default allocator for G1.
  93 class G1DefaultAllocator : public G1Allocator {
  94 protected:
  95   // Alloc region used to satisfy mutator allocation requests.
  96   MutatorAllocRegion _mutator_alloc_region;
  97 
  98   // Alloc region used to satisfy allocation requests by the GC for
  99   // survivor objects.
 100   SurvivorGCAllocRegion _survivor_gc_alloc_region;
 101 
 102   // Alloc region used to satisfy allocation requests by the GC for
 103   // old objects.
 104   OldGCAllocRegion _old_gc_alloc_region;
 105 
 106   HeapRegion* _retained_old_gc_alloc_region;
 107 public:
 108   G1DefaultAllocator(G1CollectedHeap* heap) : G1Allocator(heap), _retained_old_gc_alloc_region(NULL) { }
 109 
 110   virtual void init_mutator_alloc_region();
 111   virtual void release_mutator_alloc_region();
 112 
 113   virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info);
 114   virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info);
 115   virtual void abandon_gc_alloc_regions();
 116 
 117   virtual bool is_retained_old_region(HeapRegion* hr) {
 118     return _retained_old_gc_alloc_region == hr;
 119   }
 120 
 121   virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) {
 122     return &_mutator_alloc_region;
 123   }
 124 
 125   virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) {
 126     return &_survivor_gc_alloc_region;
 127   }
 128 
 129   virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) {
 130     return &_old_gc_alloc_region;
 131   }
 132 
 133   virtual size_t used() {
 134     assert(Heap_lock->owner() != NULL,
 135            "Should be owned on this thread's behalf.");
 136     size_t result = _summary_bytes_used;
 137 
 138     // Read only once in case it is set to NULL concurrently
 139     HeapRegion* hr = mutator_alloc_region(AllocationContext::current())->get();
 140     if (hr != NULL) {
 141       result += hr->used();
 142     }
 143     return result;
 144   }
 145 };
 146 
 147 class G1ParGCAllocBuffer: public ParGCAllocBuffer {
 148 private:
 149   bool _retired;
 150 
 151 public:
 152   G1ParGCAllocBuffer(size_t gclab_word_size);
 153   virtual ~G1ParGCAllocBuffer() {
 154     guarantee(_retired, "Allocation buffer has not been retired");
 155   }
 156 
 157   virtual void set_buf(HeapWord* buf) {
 158     ParGCAllocBuffer::set_buf(buf);
 159     _retired = false;
 160   }
 161 
 162   virtual void retire(bool end_of_gc, bool retain) {
 163     if (_retired) {
 164       return;
 165     }
 166     ParGCAllocBuffer::retire(end_of_gc, retain);
 167     _retired = true;
 168   }
 169 };
 170 
 171 class G1ParGCAllocator : public CHeapObj<mtGC> {
 172   friend class G1ParScanThreadState;
 173 protected:
 174   G1CollectedHeap* _g1h;
 175 
 176   // The survivor alignment in effect in bytes.
 177   // == 0 : don't align survivors
 178   // != 0 : align survivors to that alignment
 179   // These values were chosen to favor the non-alignment case since some
 180   // architectures have a special compare against zero instructions.
 181   const uint _survivor_alignment_bytes;
 182 
 183   size_t _alloc_buffer_waste;
 184   size_t _undo_waste;
 185 
 186   void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
 187   void add_to_undo_waste(size_t waste)         { _undo_waste += waste; }
 188 
 189   virtual void retire_alloc_buffers() = 0;
 190   virtual G1ParGCAllocBuffer* alloc_buffer(InCSetState dest, AllocationContext_t context) = 0;
 191 
 192   // Calculate the survivor space object alignment in bytes. Returns that or 0 if
 193   // there are no restrictions on survivor alignment.
 194   static uint calc_survivor_alignment_bytes() {
 195     assert(SurvivorAlignmentInBytes >= ObjectAlignmentInBytes, "sanity");
 196     if (SurvivorAlignmentInBytes == ObjectAlignmentInBytes) {
 197       // No need to align objects in the survivors differently, return 0
 198       // which means "survivor alignment is not used".
 199       return 0;
 200     } else {
 201       assert(SurvivorAlignmentInBytes > 0, "sanity");
 202       return SurvivorAlignmentInBytes;
 203     }
 204   }
 205 
 206 public:
 207   G1ParGCAllocator(G1CollectedHeap* g1h) :
 208     _g1h(g1h), _survivor_alignment_bytes(calc_survivor_alignment_bytes()),
 209     _alloc_buffer_waste(0), _undo_waste(0) {
 210   }
 211 
 212   static G1ParGCAllocator* create_allocator(G1CollectedHeap* g1h);
 213 
 214   size_t alloc_buffer_waste() { return _alloc_buffer_waste; }
 215   size_t undo_waste() {return _undo_waste; }
 216 
 217   // Allocate word_sz words in dest, either directly into the regions or by
 218   // allocating a new PLAB. Returns the address of the allocated memory, NULL if
 219   // not successful.
 220   HeapWord* allocate_direct_or_new_plab(InCSetState dest,
 221                                         size_t word_sz,
 222                                         AllocationContext_t context);
 223 
 224   // Allocate word_sz words in the PLAB of dest.  Returns the address of the
 225   // allocated memory, NULL if not successful.
 226   HeapWord* plab_allocate(InCSetState dest,
 227                           size_t word_sz,
 228                           AllocationContext_t context) {
 229     G1ParGCAllocBuffer* buffer = alloc_buffer(dest, context);
 230     if (_survivor_alignment_bytes == 0) {
 231       return buffer->allocate(word_sz);
 232     } else {
 233       return buffer->allocate_aligned(word_sz, _survivor_alignment_bytes);
 234     }
 235   }
 236 
 237   HeapWord* allocate(InCSetState dest, size_t word_sz,
 238                      AllocationContext_t context) {
 239     HeapWord* const obj = plab_allocate(dest, word_sz, context);
 240     if (obj != NULL) {
 241       return obj;
 242     }
 243     return allocate_direct_or_new_plab(dest, word_sz, context);
 244   }
 245 
 246   void undo_allocation(InCSetState dest, HeapWord* obj, size_t word_sz, AllocationContext_t context) {
 247     if (alloc_buffer(dest, context)->contains(obj)) {
 248       assert(alloc_buffer(dest, context)->contains(obj + word_sz - 1),
 249              "should contain whole object");
 250       alloc_buffer(dest, context)->undo_allocation(obj, word_sz);
 251     } else {
 252       CollectedHeap::fill_with_object(obj, word_sz);
 253       add_to_undo_waste(word_sz);
 254     }
 255   }
 256 };
 257 
 258 class G1DefaultParGCAllocator : public G1ParGCAllocator {
 259   G1ParGCAllocBuffer  _surviving_alloc_buffer;
 260   G1ParGCAllocBuffer  _tenured_alloc_buffer;
 261   G1ParGCAllocBuffer* _alloc_buffers[InCSetState::Num];
 262 
 263 public:
 264   G1DefaultParGCAllocator(G1CollectedHeap* g1h);
 265 
 266   virtual G1ParGCAllocBuffer* alloc_buffer(InCSetState dest, AllocationContext_t context) {
 267     assert(dest.is_valid(),
 268            err_msg("Allocation buffer index out-of-bounds: " CSETSTATE_FORMAT, dest.value()));
 269     assert(_alloc_buffers[dest.value()] != NULL,
 270            err_msg("Allocation buffer is NULL: " CSETSTATE_FORMAT, dest.value()));
 271     return _alloc_buffers[dest.value()];
 272   }
 273 
 274   virtual void retire_alloc_buffers() ;
 275 };
 276 
 277 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP
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