1 /*
  2  * Copyright (c) 2017, 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_CMS_CMSHEAP_HPP
 26 #define SHARE_VM_GC_CMS_CMSHEAP_HPP
 27 
 28 #include "gc/cms/concurrentMarkSweepGeneration.hpp"
 29 #include "gc/shared/collectedHeap.hpp"
 30 #include "gc/shared/gcCause.hpp"
 31 #include "gc/shared/genCollectedHeap.hpp"
 32 #include "utilities/growableArray.hpp"
 33 
 34 class CLDClosure;
 35 class GenCollectorPolicy;
 36 class GCMemoryManager;
 37 class MemoryPool;
 38 class OopsInGenClosure;
 39 class outputStream;
 40 class StrongRootsScope;
 41 class ThreadClosure;
 42 class WorkGang;
 43 
 44 class CMSHeap : public GenCollectedHeap {
 45 
 46 protected:
 47   virtual void check_gen_kinds();
 48 
 49 public:
 50   CMSHeap(GenCollectorPolicy *policy);
 51 
 52   // Returns JNI_OK on success
 53   virtual jint initialize();
 54 
 55   // Convenience function to be used in situations where the heap type can be
 56   // asserted to be this type.
 57   static CMSHeap* heap();
 58 
 59   virtual Name kind() const {
 60     return CollectedHeap::CMSHeap;
 61   }
 62 
 63   virtual const char* name() const {
 64     return "Concurrent Mark Sweep";
 65   }
 66 
 67   WorkGang* workers() const { return _workers; }
 68 
 69   virtual void print_gc_threads_on(outputStream* st) const;
 70   virtual void gc_threads_do(ThreadClosure* tc) const;
 71   virtual void print_on_error(outputStream* st) const;
 72 
 73   // Perform a full collection of the heap; intended for use in implementing
 74   // "System.gc". This implies as full a collection as the CollectedHeap
 75   // supports. Caller does not hold the Heap_lock on entry.
 76   void collect(GCCause::Cause cause);
 77 
 78   bool card_mark_must_follow_store() const {
 79     return true;
 80   }
 81 
 82   void stop();
 83   void safepoint_synchronize_begin();
 84   void safepoint_synchronize_end();
 85 
 86   virtual GrowableArray<GCMemoryManager*> memory_managers();
 87   virtual GrowableArray<MemoryPool*> memory_pools();
 88 
 89   // If "young_gen_as_roots" is false, younger generations are
 90   // not scanned as roots; in this case, the caller must be arranging to
 91   // scan the younger generations itself.  (For example, a generation might
 92   // explicitly mark reachable objects in younger generations, to avoid
 93   // excess storage retention.)
 94   void cms_process_roots(StrongRootsScope* scope,
 95                          bool young_gen_as_roots,
 96                          ScanningOption so,
 97                          bool only_strong_roots,
 98                          OopsInGenClosure* root_closure,
 99                          CLDClosure* cld_closure);
100 
101   GCMemoryManager* old_manager() const { return _old_manager; }
102 
103 private:
104   WorkGang* _workers;
105   MemoryPool* _eden_pool;
106   MemoryPool* _survivor_pool;
107   MemoryPool* _old_pool;
108 
109   virtual void gc_prologue(bool full);
110   virtual void gc_epilogue(bool full);
111 
112   virtual void initialize_serviceability();
113 
114   // Accessor for memory state verification support
115   NOT_PRODUCT(
116     virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); }
117   )
118 
119   // Returns success or failure.
120   bool create_cms_collector();
121 
122   // In support of ExplicitGCInvokesConcurrent functionality
123   bool should_do_concurrent_full_gc(GCCause::Cause cause);
124 
125   void collect_mostly_concurrent(GCCause::Cause cause);
126 };
127 
128 #endif // SHARE_VM_GC_CMS_CMSHEAP_HPP