rev 59248 : 8244777: ClassLoaderStats VM Op uses constant hash value

   1 /*
   2  * Copyright (c) 2014, 2020, 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_CLASSFILE_CLASSLOADERSTATS_HPP
  26 #define SHARE_CLASSFILE_CLASSLOADERSTATS_HPP
  27 
  28 
  29 #include "classfile/classLoaderData.hpp"
  30 #include "oops/klass.hpp"
  31 #include "oops/oop.hpp"
  32 #include "oops/oopsHierarchy.hpp"
  33 #include "runtime/vmOperations.hpp"
  34 #include "services/diagnosticCommand.hpp"
  35 #include "utilities/resourceHash.hpp"
  36 
  37 
  38 class ClassLoaderStatsDCmd : public DCmd {
  39 public:
  40   ClassLoaderStatsDCmd(outputStream* output, bool heap) :
  41     DCmd(output, heap) {
  42   }
  43 
  44   static const char* name() {
  45     return "VM.classloader_stats";
  46   }
  47 
  48   static const char* description() {
  49     return "Print statistics about all ClassLoaders.";
  50   }
  51 
  52   static const char* impact() {
  53     return "Low";
  54   }
  55 
  56   virtual void execute(DCmdSource source, TRAPS);
  57 
  58   static int num_arguments() {
  59     return 0;
  60   }
  61 
  62   static const JavaPermission permission() {
  63     JavaPermission p = {"java.lang.management.ManagementPermission",
  64                         "monitor", NULL};
  65     return p;
  66   }
  67 };
  68 
  69 
  70 class ClassLoaderStats : public ResourceObj {
  71 public:
  72   ClassLoaderData*  _cld;
  73   oop               _class_loader;
  74   oop               _parent;
  75 
  76   size_t            _chunk_sz;
  77   size_t            _block_sz;
  78   uintx             _classes_count;
  79 
  80   size_t            _hidden_chunk_sz;
  81   size_t            _hidden_block_sz;
  82   uintx             _hidden_classes_count;
  83 
  84   ClassLoaderStats() :
  85     _cld(0),
  86     _class_loader(0),
  87     _parent(0),
  88     _chunk_sz(0),
  89     _block_sz(0),
  90     _classes_count(0),
  91     _hidden_chunk_sz(0),
  92     _hidden_block_sz(0),
  93     _hidden_classes_count(0) {
  94   }
  95 };
  96 
  97 
  98 class ClassLoaderStatsClosure : public CLDClosure {
  99 protected:
 100   static bool oop_equals(oop const& s1, oop const& s2) {
 101     return s1 == s2;
 102   }
 103 
 104   static unsigned oop_hash(oop const& s1) {
 105     uintptr_t tmp = cast_from_oop<uintptr_t>(s1);
 106     unsigned hash = (unsigned)tmp;
 107     hash = ~hash + (hash << 15);
 108     hash = hash ^ (hash >> 12);
 109     hash = hash + (hash << 2);
 110     hash = hash ^ (hash >> 4);
 111     hash = hash * 2057;
 112     hash = hash ^ (hash >> 16);
 113     return hash;
 114   }
 115 
 116   typedef ResourceHashtable<oop, ClassLoaderStats*,
 117       ClassLoaderStatsClosure::oop_hash, ClassLoaderStatsClosure::oop_equals> StatsTable;
 118 
 119   outputStream* _out;
 120   StatsTable* _stats;
 121   uintx   _total_loaders;
 122   uintx   _total_classes;
 123   size_t  _total_chunk_sz;
 124   size_t  _total_block_sz;
 125 
 126 public:
 127   ClassLoaderStatsClosure(outputStream* out) :
 128     _out(out),
 129     _stats(new StatsTable()),
 130     _total_loaders(0),
 131     _total_classes(0),
 132     _total_chunk_sz(0),
 133     _total_block_sz(0) {
 134   }
 135 
 136   virtual void do_cld(ClassLoaderData* cld);
 137   virtual bool do_entry(oop const& key, ClassLoaderStats* const& cls);
 138   void print();
 139 
 140 private:
 141   void addEmptyParents(oop cl);
 142 };
 143 
 144 
 145 class ClassLoaderStatsVMOperation : public VM_Operation {
 146   outputStream* _out;
 147 
 148 public:
 149   ClassLoaderStatsVMOperation(outputStream* out) :
 150     _out(out) {
 151   }
 152 
 153   VMOp_Type type() const {
 154     return VMOp_ClassLoaderStatsOperation;
 155   }
 156 
 157   void doit();
 158 };
 159 
 160 #endif // SHARE_CLASSFILE_CLASSLOADERSTATS_HPP
--- EOF ---