1 /*

     2  * Copyright (c) 2005, 2019, 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_GC_CMS_CMSVMOPERATIONS_HPP

    26 #define SHARE_GC_CMS_CMSVMOPERATIONS_HPP

    27 

    28 #include "gc/cms/concurrentMarkSweepGeneration.hpp"

    29 #include "gc/shared/gcCause.hpp"

    30 #include "gc/shared/gcId.hpp"

    31 #include "gc/shared/gcVMOperations.hpp"

    32 #include "runtime/vmOperations.hpp"

    33 

    34 // The VM_CMS_Operation is slightly different from

    35 // a VM_GC_Operation -- and would not have subclassed easily

    36 // to VM_GC_Operation without several changes to VM_GC_Operation.

    37 // To minimize the changes, we have replicated some of the VM_GC_Operation

    38 // functionality here. We will consolidate that back by doing subclassing

    39 // as appropriate in Dolphin.

    40 //

    41 //  VM_Operation

    42 //    VM_CMS_Operation

    43 //    - implements the common portion of work done in support

    44 //      of CMS' stop-world phases (initial mark and remark).

    45 //

    46 //      VM_CMS_Initial_Mark

    47 //      VM_CMS_Final_Mark

    48 //

    49 

    50 // Forward decl.

    51 class CMSCollector;

    52 

    53 class VM_CMS_Operation: public VM_Operation {

    54  protected:

    55   CMSCollector*  _collector;                 // associated collector

    56   bool           _prologue_succeeded;     // whether doit_prologue succeeded

    57   uint           _gc_id;

    58 

    59   bool lost_race() const;

    60 

    61  public:

    62   VM_CMS_Operation(CMSCollector* collector):

    63     _collector(collector),

    64     _prologue_succeeded(false),

    65     _gc_id(GCId::current()) {}

    66   ~VM_CMS_Operation() {}

    67 

    68   // The legal collector state for executing this CMS op.

    69   virtual const CMSCollector::CollectorState legal_state() const = 0;

    70 

    71   // Whether the pending list lock needs to be held

    72   virtual const bool needs_pending_list_lock() const = 0;

    73 

    74   // Execute operations in the context of the caller,

    75   // prior to execution of the vm operation itself.

    76   virtual bool doit_prologue();

    77   // Execute operations in the context of the caller,

    78   // following completion of the vm operation.

    79   virtual void doit_epilogue();

    80 

    81   virtual bool evaluate_at_safepoint() const { return true; }

    82   virtual bool is_cheap_allocated() const { return false; }

    83   virtual bool allow_nested_vm_operations() const  { return false; }

    84   bool prologue_succeeded() const { return _prologue_succeeded; }

    85 

    86   void verify_before_gc();

    87   void verify_after_gc();

    88 };

    89 

    90 

    91 // VM_CMS_Operation for the initial marking phase of CMS.

    92 class VM_CMS_Initial_Mark: public VM_CMS_Operation {

    93  public:

    94   VM_CMS_Initial_Mark(CMSCollector* _collector) :

    95     VM_CMS_Operation(_collector) {}

    96 

    97   virtual VMOp_Type type() const { return VMOp_CMS_Initial_Mark; }

    98   virtual void doit();

    99 

   100   virtual const CMSCollector::CollectorState legal_state() const {

   101     return CMSCollector::InitialMarking;

   102   }

   103 

   104   virtual const bool needs_pending_list_lock() const {

   105     return false;

   106   }

   107 };

   108 

   109 // VM_CMS_Operation for the final remark phase of CMS.

   110 class VM_CMS_Final_Remark: public VM_CMS_Operation {

   111  public:

   112   VM_CMS_Final_Remark(CMSCollector* _collector) :

   113     VM_CMS_Operation(_collector) {}

   114   virtual VMOp_Type type() const { return VMOp_CMS_Final_Remark; }

   115   virtual void doit();

   116 

   117   virtual const CMSCollector::CollectorState legal_state() const {

   118     return CMSCollector::FinalMarking;

   119   }

   120 

   121   virtual const bool needs_pending_list_lock() const {

   122     return true;

   123   }

   124 };

   125 

   126 

   127 // VM operation to invoke a concurrent collection of the heap as a

   128 // GenCollectedHeap heap.

   129 class VM_GenCollectFullConcurrent: public VM_GC_Operation {

   130  public:

   131   VM_GenCollectFullConcurrent(uint gc_count_before,

   132                               uint full_gc_count_before,

   133                               GCCause::Cause gc_cause)

   134     : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */)

   135   {

   136     assert(FullGCCount_lock != NULL, "Error");

   137   }

   138   ~VM_GenCollectFullConcurrent() {}

   139   virtual VMOp_Type type() const { return VMOp_GenCollectFullConcurrent; }

   140   virtual void doit();

   141   virtual void doit_epilogue();

   142   virtual bool is_cheap_allocated() const { return false; }

   143   virtual bool evaluate_at_safepoint() const;

   144 };

   145 

   146 #endif // SHARE_GC_CMS_CMSVMOPERATIONS_HPP