1 /*
   2  * Copyright (c) 2005, 2010, 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 // HeapDumper is used to dump the java heap to file in HPROF binary format:
  26 //
  27 //  { HeapDumper dumper(true /* full GC before heap dump */);
  28 //    if (dumper.dump("/export/java.hprof")) {
  29 //      ResourceMark rm;
  30 //      tty->print_cr("Dump failed: %s", dumper.error_as_C_string());
  31 //    } else {
  32 //      // dump succeeded
  33 //    }
  34 //  }
  35 //
  36 
  37 class HeapDumper : public StackObj {
  38  private:
  39   char* _error;
  40   bool _print_to_tty;
  41   bool _gc_before_heap_dump;
  42   bool _oome;
  43   elapsedTimer _t;
  44 
  45   HeapDumper(bool gc_before_heap_dump, bool print_to_tty, bool oome) :
  46     _gc_before_heap_dump(gc_before_heap_dump), _error(NULL), _print_to_tty(print_to_tty), _oome(oome) { }
  47 
  48   // string representation of error
  49   char* error() const                   { return _error; }
  50   void set_error(char* error);
  51 
  52   // indicates if progress messages can be sent to tty
  53   bool print_to_tty() const             { return _print_to_tty; }
  54 
  55   // internal timer.
  56   elapsedTimer* timer()                 { return &_t; }
  57 
  58   static void dump_heap(bool oome);
  59 
  60  public:
  61   HeapDumper(bool gc_before_heap_dump) :
  62     _gc_before_heap_dump(gc_before_heap_dump), _error(NULL), _print_to_tty(false), _oome(false) { }
  63 
  64   ~HeapDumper();
  65 
  66   // dumps the heap to the specified file, returns 0 if success.
  67   int dump(const char* path);
  68 
  69   // returns error message (resource allocated), or NULL if no error
  70   char* error_as_C_string() const;
  71 
  72   static void dump_heap()    KERNEL_RETURN;
  73 
  74   static void dump_heap_from_oome()    KERNEL_RETURN;
  75 };