1 /*
   2  * Copyright (c) 2002, 2004, 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 // A GSpaceCounter is a holder class for performance counters
  26 // that track a space;
  27 
  28 class GSpaceCounters: public CHeapObj {
  29   friend class VMStructs;
  30 
  31  private:
  32   PerfVariable*      _capacity;
  33   PerfVariable*      _used;
  34 
  35   // Constant PerfData types don't need to retain a reference.
  36   // However, it's a good idea to document them here.
  37   // PerfConstant*     _size;
  38 
  39   Generation*       _gen;
  40   char*             _name_space;
  41 
  42  public:
  43 
  44   GSpaceCounters(const char* name, int ordinal, size_t max_size, Generation* g,
  45                  GenerationCounters* gc, bool sampled=true);
  46 
  47   ~GSpaceCounters() {
  48     if (_name_space != NULL) FREE_C_HEAP_ARRAY(char, _name_space);
  49   }
  50 
  51   inline void update_capacity() {
  52     _capacity->set_value(_gen->capacity());
  53   }
  54 
  55   inline void update_used() {
  56     _used->set_value(_gen->used());
  57   }
  58 
  59   // special version of update_used() to allow the used value to be
  60   // passed as a parameter. This method can can be used in cases were
  61   // the  utilization is already known and/or when the _gen->used()
  62   // method is known to be expensive and we want to avoid unnecessary
  63   // calls to it.
  64   //
  65   inline void update_used(size_t used) {
  66     _used->set_value(used);
  67   }
  68 
  69   inline void inc_used(size_t size) {
  70     _used->inc(size);
  71   }
  72 
  73   debug_only(
  74     // for security reasons, we do not allow arbitrary reads from
  75     // the counters as they may live in shared memory.
  76     jlong used() {
  77       return _used->get_value();
  78     }
  79     jlong capacity() {
  80       return _used->get_value();
  81     }
  82   )
  83 
  84   inline void update_all() {
  85     update_used();
  86     update_capacity();
  87   }
  88 
  89   const char* name_space() const        { return _name_space; }
  90 };
  91 
  92 class GenerationUsedHelper : public PerfLongSampleHelper {
  93   private:
  94     Generation* _gen;
  95 
  96   public:
  97     GenerationUsedHelper(Generation* g) : _gen(g) { }
  98 
  99     inline jlong take_sample() {
 100       return _gen->used();
 101     }
 102 };