1 /*
   2  * Copyright (c) 2005, 2011, 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
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  23  */
  24 
  25 #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_VMCMSOPERATIONS_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_VMCMSOPERATIONS_HPP
  27 
  28 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp"
  29 #include "gc_implementation/shared/vmGCOperations.hpp"
  30 #include "gc_interface/gcCause.hpp"
  31 #include "runtime/vm_operations.hpp"
  32 
  33 // The VM_CMS_Operation is slightly different from
  34 // a VM_GC_Operation -- and would not have subclassed easily
  35 // to VM_GC_Operation without several changes to VM_GC_Operation.
  36 // To minimize the changes, we have replicated some of the VM_GC_Operation
  37 // functionality here. We will consolidate that back by doing subclassing
  38 // as appropriate in Dolphin.
  39 //
  40 //  VM_Operation
  41 //    VM_CMS_Operation
  42 //    - implements the common portion of work done in support
  43 //      of CMS' stop-world phases (initial mark and remark).
  44 //
  45 //      VM_CMS_Initial_Mark
  46 //      VM_CMS_Final_Mark
  47 //
  48 
  49 // Forward decl.
  50 class CMSCollector;
  51 
  52 class VM_CMS_Operation: public VM_Operation {
  53  protected:
  54   CMSCollector*  _collector;                 // associated collector
  55   bool           _prologue_succeeded;     // whether doit_prologue succeeded
  56 
  57   bool lost_race() const;
  58 
  59   // java.lang.ref.Reference support
  60   void acquire_pending_list_lock();
  61   void release_and_notify_pending_list_lock();
  62 
  63  public:
  64   VM_CMS_Operation(CMSCollector* collector):
  65     _collector(collector),
  66     _prologue_succeeded(false) {}
  67   ~VM_CMS_Operation() {}
  68 
  69   // The legal collector state for executing this CMS op.
  70   virtual const CMSCollector::CollectorState legal_state() const = 0;
  71 
  72   // Whether the pending list lock needs to be held
  73   virtual const bool needs_pll() const = 0;
  74 
  75   // Execute operations in the context of the caller,
  76   // prior to execution of the vm operation itself.
  77   virtual bool doit_prologue();
  78   // Execute operations in the context of the caller,
  79   // following completion of the vm operation.
  80   virtual void doit_epilogue();
  81 
  82   virtual bool evaluate_at_safepoint() const { return true; }
  83   virtual bool is_cheap_allocated() const { return false; }
  84   virtual bool allow_nested_vm_operations() const  { return false; }
  85   bool prologue_succeeded() const { return _prologue_succeeded; }
  86 
  87   void verify_before_gc();
  88   void verify_after_gc();
  89 };
  90 
  91 
  92 // VM_CMS_Operation for the initial marking phase of CMS.
  93 class VM_CMS_Initial_Mark: public VM_CMS_Operation {
  94  public:
  95   VM_CMS_Initial_Mark(CMSCollector* _collector) :
  96     VM_CMS_Operation(_collector) {}
  97 
  98   virtual VMOp_Type type() const { return VMOp_CMS_Initial_Mark; }
  99   virtual void doit();
 100 
 101   virtual const CMSCollector::CollectorState legal_state() const {
 102     return CMSCollector::InitialMarking;
 103   }
 104 
 105   virtual const bool needs_pll() const {
 106     return false;
 107   }
 108 };
 109 
 110 // VM_CMS_Operation for the final remark phase of CMS.
 111 class VM_CMS_Final_Remark: public VM_CMS_Operation {
 112  public:
 113   VM_CMS_Final_Remark(CMSCollector* _collector) :
 114     VM_CMS_Operation(_collector) {}
 115   virtual VMOp_Type type() const { return VMOp_CMS_Final_Remark; }
 116   virtual void doit();
 117 
 118   virtual const CMSCollector::CollectorState legal_state() const {
 119     return CMSCollector::FinalMarking;
 120   }
 121 
 122   virtual const bool needs_pll() const {
 123     return true;
 124   }
 125 };
 126 
 127 
 128 // VM operation to invoke a concurrent collection of the heap as a
 129 // GenCollectedHeap heap.
 130 class VM_GenCollectFullConcurrent: public VM_GC_Operation {
 131   bool _disabled_icms;
 132  public:
 133   VM_GenCollectFullConcurrent(unsigned int gc_count_before,
 134                               unsigned int full_gc_count_before,
 135                               GCCause::Cause gc_cause)
 136     : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */),
 137       _disabled_icms(false)
 138   {
 139     assert(FullGCCount_lock != NULL, "Error");
 140     assert(UseAsyncConcMarkSweepGC, "Else will hang caller");
 141   }
 142   ~VM_GenCollectFullConcurrent() {}
 143   virtual VMOp_Type type() const { return VMOp_GenCollectFullConcurrent; }
 144   virtual void doit();
 145   virtual void doit_epilogue();
 146   virtual bool is_cheap_allocated() const { return false; }
 147   virtual bool evaluate_at_safepoint() const;
 148 };
 149 
 150 #endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_VMCMSOPERATIONS_HPP