1 /*

     2  * Copyright (c) 2017, 2018, 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_JFR_LEAKPROFILER_UTILITIES_SAVERESTORE_HPP

    26 #define SHARE_VM_JFR_LEAKPROFILER_UTILITIES_SAVERESTORE_HPP

    27 

    28 #include "memory/allocation.hpp"

    29 #include "memory/iterator.hpp"

    30 #include "oops/markOop.hpp"

    31 #include "utilities/growableArray.hpp"

    32 

    33 template <typename T, typename Impl>

    34 class SaveRestore {

    35  private:

    36   Impl _impl;

    37  public:

    38   SaveRestore() : _impl() {

    39     _impl.setup();

    40   }

    41 

    42   void save(T const& value) {

    43     _impl.save(value);

    44   }

    45 

    46   ~SaveRestore() {

    47     _impl.restore();

    48   }

    49 };

    50 

    51 template <typename T, typename Context>

    52 class ContextStore {

    53 private:

    54   GrowableArray<Context>* _storage;

    55 public:

    56   ContextStore() : _storage(NULL) {}

    57 

    58   void setup() {

    59     assert(_storage == NULL, "invariant");

    60     _storage = new GrowableArray<Context>(16);

    61   }

    62 

    63   void save(T const& value) {

    64     _storage->push(Context(value));

    65   }

    66 

    67   void restore() {

    68     for (int i = 0; i < _storage->length(); ++i) {

    69       _storage->at(i).~Context();

    70     }

    71   }

    72 };

    73 

    74 /*

    75 * This class will save the original mark oop of an object sample object.

    76 * It will then install an "identifier" mark oop to be used for

    77 * identification purposes in the search for reference chains.

    78 * The destructor will restore the original mark oop.

    79 */

    80 

    81 class MarkOopContext {

    82  private:

    83   oop _obj;

    84   markOop _mark_oop;

    85   void swap(MarkOopContext& rhs);

    86  public:

    87   MarkOopContext();

    88   MarkOopContext(const oop obj);

    89   MarkOopContext(const MarkOopContext& rhs);

    90   void operator=(MarkOopContext rhs);

    91   ~MarkOopContext();

    92 };

    93 

    94 typedef SaveRestore<oop, ContextStore<oop, MarkOopContext> > SaveRestoreMarkOops;

    95 

    96 class ClassLoaderData;

    97 

    98 class CLDClaimContext {

    99  private:

   100   ClassLoaderData* _cld;

   101   void swap(CLDClaimContext& rhs);

   102  public:

   103   CLDClaimContext();

   104   CLDClaimContext(ClassLoaderData* cld);

   105   CLDClaimContext(const CLDClaimContext& rhs);

   106   void operator=(CLDClaimContext rhs);

   107   ~CLDClaimContext();

   108 };

   109 

   110 typedef SaveRestore<ClassLoaderData*, ContextStore<ClassLoaderData*, CLDClaimContext> > SaveRestoreCLDClaimState;

   111 

   112 class CLDClaimStateClosure : public CLDClosure {

   113  private:

   114   SaveRestoreCLDClaimState _state;

   115  public:

   116   CLDClaimStateClosure();

   117   void do_cld(ClassLoaderData* cld);

   118 };

   119 

   120 class SaveRestoreCLDClaimBits : public StackObj {

   121  private:

   122   CLDClaimStateClosure _claim_state_closure;

   123  public:

   124   SaveRestoreCLDClaimBits();

   125   ~SaveRestoreCLDClaimBits();

   126 };

   127 

   128 #endif // SHARE_VM_JFR_LEAKPROFILER_UTILITIES_SAVERESTORE_HPP