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 MemoryManager;
  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 protected:
  46   virtual void check_gen_kinds();
  47 
  48 public:
  49   CMSHeap(GenCollectorPolicy *policy);
  50 
  51   // Returns JNI_OK on success
  52   virtual jint initialize();
  53 
  54   // Convenience function to be used in situations where the heap type can be
  55   // asserted to be this type.
  56   static CMSHeap* heap();
  57 
  58   virtual Name kind() const {
  59     return CollectedHeap::CMSHeap;
  60   }
  61 
  62   virtual const char* name() const {
  63     return "Concurrent Mark Sweep";
  64   }
  65 
  66   WorkGang* workers() const { return _workers; }
  67 
  68   virtual void print_gc_threads_on(outputStream* st) const;
  69   virtual void gc_threads_do(ThreadClosure* tc) const;
  70   virtual void print_on_error(outputStream* st) const;
  71 
  72   // Perform a full collection of the heap; intended for use in implementing
  73   // "System.gc". This implies as full a collection as the CollectedHeap
  74   // supports. Caller does not hold the Heap_lock on entry.
  75   void collect(GCCause::Cause cause);
  76 
  77   bool card_mark_must_follow_store() const {
  78     return true;
  79   }
  80 
  81   void stop();
  82   void safepoint_synchronize_begin();
  83   void safepoint_synchronize_end();
  84 
  85   virtual void init_memory_managers();
  86   virtual GrowableArray<MemoryManager*> 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 private:
 102   WorkGang* _workers;
 103 
 104   virtual void gc_prologue(bool full);
 105   virtual void gc_epilogue(bool full);
 106 
 107   // Accessor for memory state verification support
 108   NOT_PRODUCT(
 109     virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); }
 110   )
 111 
 112   // Returns success or failure.
 113   bool create_cms_collector();
 114 
 115   // In support of ExplicitGCInvokesConcurrent functionality
 116   bool should_do_concurrent_full_gc(GCCause::Cause cause);
 117 
 118   void collect_mostly_concurrent(GCCause::Cause cause);
 119 };
 120 
 121 #endif // SHARE_VM_GC_CMS_CMSHEAP_HPP