1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   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.
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   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
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  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
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  24 
  25 #ifndef SHARE_GC_CMS_CMSHEAP_HPP
  26 #define SHARE_GC_CMS_CMSHEAP_HPP
  27 
  28 #include "gc/cms/concurrentMarkSweepGeneration.hpp"
  29 #include "gc/cms/parNewGeneration.hpp"
  30 #include "gc/shared/collectedHeap.hpp"
  31 #include "gc/shared/gcCause.hpp"
  32 #include "gc/shared/genCollectedHeap.hpp"
  33 #include "gc/shared/oopStorageParState.hpp"
  34 #include "utilities/growableArray.hpp"
  35 
  36 class CLDClosure;
  37 class GCMemoryManager;
  38 class MemoryPool;
  39 class OopsInGenClosure;
  40 class outputStream;
  41 class StrongRootsScope;
  42 class ThreadClosure;
  43 class WorkGang;
  44 
  45 class CMSHeap : public GenCollectedHeap {
  46 public:
  47   CMSHeap();
  48 
  49   // Returns JNI_OK on success
  50   virtual jint initialize();
  51   virtual CardTableRS* create_rem_set(const MemRegion& reserved_region);
  52 
  53   // Convenience function to be used in situations where the heap type can be
  54   // asserted to be this type.
  55   static CMSHeap* heap();
  56 
  57   virtual Name kind() const {
  58     return CollectedHeap::CMS;
  59   }
  60 
  61   virtual const char* name() const {
  62     return "Concurrent Mark Sweep";
  63   }
  64 
  65   WorkGang* workers() const { return _workers; }
  66 
  67   virtual void print_gc_threads_on(outputStream* st) const;
  68   virtual void gc_threads_do(ThreadClosure* tc) const;
  69   virtual void print_on_error(outputStream* st) const;
  70 
  71   // Perform a full collection of the heap; intended for use in implementing
  72   // "System.gc". This implies as full a collection as the CollectedHeap
  73   // supports. Caller does not hold the Heap_lock on entry.
  74   void collect(GCCause::Cause cause);
  75 
  76   void stop();
  77   void safepoint_synchronize_begin();
  78   void safepoint_synchronize_end();
  79 
  80   virtual GrowableArray<GCMemoryManager*> memory_managers();
  81   virtual GrowableArray<MemoryPool*> memory_pools();
  82 
  83   // If "young_gen_as_roots" is false, younger generations are
  84   // not scanned as roots; in this case, the caller must be arranging to
  85   // scan the younger generations itself.  (For example, a generation might
  86   // explicitly mark reachable objects in younger generations, to avoid
  87   // excess storage retention.)
  88   void cms_process_roots(StrongRootsScope* scope,
  89                          bool young_gen_as_roots,
  90                          ScanningOption so,
  91                          bool only_strong_roots,
  92                          OopsInGenClosure* root_closure,
  93                          CLDClosure* cld_closure);
  94 
  95   GCMemoryManager* old_manager() const { return _old_manager; }
  96 
  97   ParNewGeneration* young_gen() const {
  98     assert(_young_gen->kind() == Generation::ParNew, "Wrong generation type");
  99     return static_cast<ParNewGeneration*>(_young_gen);
 100   }
 101 
 102   ConcurrentMarkSweepGeneration* old_gen() const {
 103     assert(_old_gen->kind() == Generation::ConcurrentMarkSweep, "Wrong generation kind");
 104     return static_cast<ConcurrentMarkSweepGeneration*>(_old_gen);
 105   }
 106 
 107   // Apply "cur->do_oop" or "older->do_oop" to all the oops in objects
 108   // allocated since the last call to save_marks in the young generation.
 109   // The "cur" closure is applied to references in the younger generation
 110   // at "level", and the "older" closure to older generations.
 111   template <typename OopClosureType1, typename OopClosureType2>
 112   void oop_since_save_marks_iterate(OopClosureType1* cur,
 113                                     OopClosureType2* older);
 114 
 115 private:
 116   WorkGang* _workers;
 117   MemoryPool* _eden_pool;
 118   MemoryPool* _survivor_pool;
 119   MemoryPool* _old_pool;
 120 
 121   virtual void gc_prologue(bool full);
 122   virtual void gc_epilogue(bool full);
 123 
 124   virtual void initialize_serviceability();
 125 
 126   // Accessor for memory state verification support
 127   NOT_PRODUCT(
 128     virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); }
 129   )
 130 
 131   // Returns success or failure.
 132   bool create_cms_collector();
 133 
 134   // In support of ExplicitGCInvokesConcurrent functionality
 135   bool should_do_concurrent_full_gc(GCCause::Cause cause);
 136 
 137   void collect_mostly_concurrent(GCCause::Cause cause);
 138 
 139   // CMS forwards some non-heap value into the mark oop to reserve oops during
 140   // promotion, so we can't assert about obj alignment or that the forwardee is in heap
 141   virtual void check_oop_location(void* addr) const {}
 142 };
 143 
 144 #endif // SHARE_GC_CMS_CMSHEAP_HPP