src/share/vm/gc_implementation/g1/g1Allocator.hpp

Fri, 05 Sep 2014 09:49:19 +0200

author
sjohanss
date
Fri, 05 Sep 2014 09:49:19 +0200
changeset 7118
227a9e5e4b4a
child 7131
d35872270666
permissions
-rw-r--r--

8057536: Refactor G1 to allow context specific allocations
Summary: Splitting out a g1 allocator class to simply specialized allocators which can associate each allocation with a given context.
Reviewed-by: mgerdin, brutisso

     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  */
    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP
    26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP
    28 #include "gc_implementation/g1/g1AllocationContext.hpp"
    29 #include "gc_implementation/g1/g1AllocRegion.hpp"
    30 #include "gc_implementation/shared/parGCAllocBuffer.hpp"
    32 enum GCAllocPurpose {
    33   GCAllocForTenured,
    34   GCAllocForSurvived,
    35   GCAllocPurposeCount
    36 };
    38 // Base class for G1 allocators.
    39 class G1Allocator : public CHeapObj<mtGC> {
    40   friend class VMStructs;
    41 protected:
    42   G1CollectedHeap* _g1h;
    44   // Outside of GC pauses, the number of bytes used in all regions other
    45   // than the current allocation region.
    46   size_t _summary_bytes_used;
    48 public:
    49    G1Allocator(G1CollectedHeap* heap) :
    50      _g1h(heap), _summary_bytes_used(0) { }
    52    static G1Allocator* create_allocator(G1CollectedHeap* g1h);
    54    virtual void init_mutator_alloc_region() = 0;
    55    virtual void release_mutator_alloc_region() = 0;
    57    virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info) = 0;
    58    virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) = 0;
    59    virtual void abandon_gc_alloc_regions() = 0;
    61    virtual MutatorAllocRegion*    mutator_alloc_region(AllocationContext_t context) = 0;
    62    virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) = 0;
    63    virtual OldGCAllocRegion*      old_gc_alloc_region(AllocationContext_t context) = 0;
    64    virtual size_t                 used() = 0;
    65    virtual bool                   is_retained_old_region(HeapRegion* hr) = 0;
    67    void                           reuse_retained_old_region(EvacuationInfo& evacuation_info,
    68                                                             OldGCAllocRegion* old,
    69                                                             HeapRegion** retained);
    71    size_t used_unlocked() const {
    72      return _summary_bytes_used;
    73    }
    75    void increase_used(size_t bytes) {
    76      _summary_bytes_used += bytes;
    77    }
    79    void decrease_used(size_t bytes) {
    80      assert(_summary_bytes_used >= bytes,
    81             err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" should be >= bytes: "SIZE_FORMAT,
    82                 _summary_bytes_used, bytes));
    83      _summary_bytes_used -= bytes;
    84    }
    86    void set_used(size_t bytes) {
    87      _summary_bytes_used = bytes;
    88    }
    89 };
    91 // The default allocator for G1.
    92 class G1DefaultAllocator : public G1Allocator {
    93 protected:
    94   // Alloc region used to satisfy mutator allocation requests.
    95   MutatorAllocRegion _mutator_alloc_region;
    97   // Alloc region used to satisfy allocation requests by the GC for
    98   // survivor objects.
    99   SurvivorGCAllocRegion _survivor_gc_alloc_region;
   101   // Alloc region used to satisfy allocation requests by the GC for
   102   // old objects.
   103   OldGCAllocRegion _old_gc_alloc_region;
   105   HeapRegion* _retained_old_gc_alloc_region;
   106 public:
   107   G1DefaultAllocator(G1CollectedHeap* heap) : G1Allocator(heap), _retained_old_gc_alloc_region(NULL) { }
   109   virtual void init_mutator_alloc_region();
   110   virtual void release_mutator_alloc_region();
   112   virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info);
   113   virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info);
   114   virtual void abandon_gc_alloc_regions();
   116   virtual bool is_retained_old_region(HeapRegion* hr) {
   117     return _retained_old_gc_alloc_region == hr;
   118   }
   120   virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) {
   121     return &_mutator_alloc_region;
   122   }
   124   virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) {
   125     return &_survivor_gc_alloc_region;
   126   }
   128   virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) {
   129     return &_old_gc_alloc_region;
   130   }
   132   virtual size_t used() {
   133     assert(Heap_lock->owner() != NULL,
   134            "Should be owned on this thread's behalf.");
   135     size_t result = _summary_bytes_used;
   137     // Read only once in case it is set to NULL concurrently
   138     HeapRegion* hr = mutator_alloc_region(AllocationContext::current())->get();
   139     if (hr != NULL) {
   140       result += hr->used();
   141     }
   142     return result;
   143   }
   144 };
   146 class G1ParGCAllocBuffer: public ParGCAllocBuffer {
   147 private:
   148   bool _retired;
   150 public:
   151   G1ParGCAllocBuffer(size_t gclab_word_size);
   152   virtual ~G1ParGCAllocBuffer() {
   153     guarantee(_retired, "Allocation buffer has not been retired");
   154   }
   156   virtual void set_buf(HeapWord* buf) {
   157     ParGCAllocBuffer::set_buf(buf);
   158     _retired = false;
   159   }
   161   virtual void retire(bool end_of_gc, bool retain) {
   162     if (_retired) {
   163       return;
   164     }
   165     ParGCAllocBuffer::retire(end_of_gc, retain);
   166     _retired = true;
   167   }
   168 };
   170 class G1ParGCAllocator : public CHeapObj<mtGC> {
   171   friend class G1ParScanThreadState;
   172 protected:
   173   G1CollectedHeap* _g1h;
   175   size_t _alloc_buffer_waste;
   176   size_t _undo_waste;
   178   void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
   179   void add_to_undo_waste(size_t waste)         { _undo_waste += waste; }
   181   HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context);
   183   virtual void retire_alloc_buffers() = 0;
   184   virtual G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose, AllocationContext_t context) = 0;
   186 public:
   187   G1ParGCAllocator(G1CollectedHeap* g1h) :
   188     _g1h(g1h), _alloc_buffer_waste(0), _undo_waste(0) {
   189   }
   191   static G1ParGCAllocator* create_allocator(G1CollectedHeap* g1h);
   193   size_t alloc_buffer_waste() { return _alloc_buffer_waste; }
   194   size_t undo_waste() {return _undo_waste; }
   196   HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) {
   197     HeapWord* obj = NULL;
   198     if (purpose == GCAllocForSurvived) {
   199       obj = alloc_buffer(purpose, context)->allocate_aligned(word_sz, SurvivorAlignmentInBytes);
   200     } else {
   201       obj = alloc_buffer(purpose, context)->allocate(word_sz);
   202     }
   203     if (obj != NULL) {
   204       return obj;
   205     }
   206     return allocate_slow(purpose, word_sz, context);
   207   }
   209   void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz, AllocationContext_t context) {
   210     if (alloc_buffer(purpose, context)->contains(obj)) {
   211       assert(alloc_buffer(purpose, context)->contains(obj + word_sz - 1),
   212              "should contain whole object");
   213       alloc_buffer(purpose, context)->undo_allocation(obj, word_sz);
   214     } else {
   215       CollectedHeap::fill_with_object(obj, word_sz);
   216       add_to_undo_waste(word_sz);
   217     }
   218   }
   219 };
   221 class G1DefaultParGCAllocator : public G1ParGCAllocator {
   222   G1ParGCAllocBuffer  _surviving_alloc_buffer;
   223   G1ParGCAllocBuffer  _tenured_alloc_buffer;
   224   G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
   226 public:
   227   G1DefaultParGCAllocator(G1CollectedHeap* g1h);
   229   virtual G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose, AllocationContext_t context) {
   230     return _alloc_buffers[purpose];
   231   }
   233   virtual void retire_alloc_buffers() ;
   234 };
   236 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP

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