1 /*
   2  * Copyright (c) 2001, 2009, 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 // VM_operations for the G1 collector.
  26 // VM_GC_Operation:
  27 //   - VM_CGC_Operation
  28 //   - VM_G1CollectFull
  29 //   - VM_G1CollectForAllocation
  30 //   - VM_G1IncCollectionPause
  31 //   - VM_G1PopRegionCollectionPause
  32 
  33 class VM_G1CollectFull: public VM_GC_Operation {
  34  public:
  35   VM_G1CollectFull(unsigned int gc_count_before,
  36                    unsigned int full_gc_count_before,
  37                    GCCause::Cause cause)
  38     : VM_GC_Operation(gc_count_before, full_gc_count_before) {
  39     _gc_cause = cause;
  40   }
  41   ~VM_G1CollectFull() {}
  42   virtual VMOp_Type type() const { return VMOp_G1CollectFull; }
  43   virtual void doit();
  44   virtual const char* name() const {
  45     return "full garbage-first collection";
  46   }
  47 };
  48 
  49 class VM_G1CollectForAllocation: public VM_GC_Operation {
  50  private:
  51   HeapWord*   _res;
  52   size_t      _size;                       // size of object to be allocated
  53  public:
  54   VM_G1CollectForAllocation(size_t size, int gc_count_before)
  55     : VM_GC_Operation(gc_count_before) {
  56     _size        = size;
  57     _res         = NULL;
  58   }
  59   ~VM_G1CollectForAllocation()        {}
  60   virtual VMOp_Type type() const { return VMOp_G1CollectForAllocation; }
  61   virtual void doit();
  62   virtual const char* name() const {
  63     return "garbage-first collection to satisfy allocation";
  64   }
  65   HeapWord* result() { return _res; }
  66 };
  67 
  68 class VM_G1IncCollectionPause: public VM_GC_Operation {
  69 private:
  70   bool _should_initiate_conc_mark;
  71   double _target_pause_time_ms;
  72   unsigned int _full_collections_completed_before;
  73 public:
  74   VM_G1IncCollectionPause(unsigned int   gc_count_before,
  75                           bool           should_initiate_conc_mark,
  76                           double         target_pause_time_ms,
  77                           GCCause::Cause cause)
  78     : VM_GC_Operation(gc_count_before),
  79       _full_collections_completed_before(0),
  80       _should_initiate_conc_mark(should_initiate_conc_mark),
  81       _target_pause_time_ms(target_pause_time_ms) {
  82     guarantee(target_pause_time_ms > 0.0,
  83               err_msg("target_pause_time_ms = %1.6lf should be positive",
  84                       target_pause_time_ms));
  85 
  86     _gc_cause = cause;
  87   }
  88   virtual VMOp_Type type() const { return VMOp_G1IncCollectionPause; }
  89   virtual void doit();
  90   virtual void doit_epilogue();
  91   virtual const char* name() const {
  92     return "garbage-first incremental collection pause";
  93   }
  94 };
  95 
  96 // Concurrent GC stop-the-world operations such as initial and final mark;
  97 // consider sharing these with CMS's counterparts.
  98 class VM_CGC_Operation: public VM_Operation {
  99   VoidClosure* _cl;
 100   const char* _printGCMessage;
 101  public:
 102   VM_CGC_Operation(VoidClosure* cl, const char *printGCMsg) :
 103     _cl(cl),
 104     _printGCMessage(printGCMsg)
 105     {}
 106 
 107   ~VM_CGC_Operation() {}
 108 
 109   virtual VMOp_Type type() const { return VMOp_CGC_Operation; }
 110   virtual void doit();
 111   virtual bool doit_prologue();
 112   virtual void doit_epilogue();
 113   virtual const char* name() const {
 114     return "concurrent gc";
 115   }
 116 };