1 /*
   2  * Copyright (c) 2002, 2014, 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_IMPLEMENTATION_SHARED_GSPACECOUNTERS_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_GSPACECOUNTERS_HPP
  27 
  28 #include "utilities/macros.hpp"
  29 #if INCLUDE_ALL_GCS
  30 #include "gc_implementation/shared/generationCounters.hpp"
  31 #include "memory/generation.hpp"
  32 #include "runtime/perfData.hpp"
  33 #endif // INCLUDE_ALL_GCS
  34 
  35 // A GSpaceCounter is a holder class for performance counters
  36 // that track a space;
  37 
  38 class GSpaceCounters: public CHeapObj<mtGC> {
  39   friend class VMStructs;
  40 
  41  private:
  42   PerfVariable*      _capacity;
  43   PerfVariable*      _used;
  44 
  45   // Constant PerfData types don't need to retain a reference.
  46   // However, it's a good idea to document them here.
  47   // PerfConstant*     _size;
  48 
  49   Generation*       _gen;
  50   char*             _name_space;
  51 
  52  public:
  53 
  54   GSpaceCounters(const char* name, int ordinal, size_t max_size, Generation* g,
  55                  GenerationCounters* gc, bool sampled=true);
  56 
  57   ~GSpaceCounters() {
  58     if (_name_space != NULL) FREE_C_HEAP_ARRAY(char, _name_space);
  59   }
  60 
  61   inline void update_capacity() {
  62     _capacity->set_value(_gen->capacity());
  63   }
  64 
  65   inline void update_used() {
  66     _used->set_value(_gen->used());
  67   }
  68 
  69   // special version of update_used() to allow the used value to be
  70   // passed as a parameter. This method can can be used in cases were
  71   // the  utilization is already known and/or when the _gen->used()
  72   // method is known to be expensive and we want to avoid unnecessary
  73   // calls to it.
  74   //
  75   inline void update_used(size_t used) {
  76     _used->set_value(used);
  77   }
  78 
  79   inline void inc_used(size_t size) {
  80     _used->inc(size);
  81   }
  82 
  83   debug_only(
  84     // for security reasons, we do not allow arbitrary reads from
  85     // the counters as they may live in shared memory.
  86     jlong used() {
  87       return _used->get_value();
  88     }
  89     jlong capacity() {
  90       return _used->get_value();
  91     }
  92   )
  93 
  94   inline void update_all() {
  95     update_used();
  96     update_capacity();
  97   }
  98 
  99   const char* name_space() const        { return _name_space; }
 100 };
 101 
 102 class GenerationUsedHelper : public PerfLongSampleHelper {
 103   private:
 104     Generation* _gen;
 105 
 106   public:
 107     GenerationUsedHelper(Generation* g) : _gen(g) { }
 108 
 109     inline jlong take_sample() {
 110       return _gen->used();
 111     }
 112 };
 113 
 114 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_GSPACECOUNTERS_HPP