src/share/vm/utilities/nativeCallStack.hpp

Wed, 27 Aug 2014 08:19:12 -0400

author
zgu
date
Wed, 27 Aug 2014 08:19:12 -0400
changeset 7074
833b0f92429a
child 7078
c6211b707068
permissions
-rw-r--r--

8046598: Scalable Native memory tracking development
Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill

     1 /*
     2  * Copyright (c) 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  */
    25 #ifndef SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP
    26 #define SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP
    28 #include "memory/allocation.hpp"
    29 #include "services/nmtCommon.hpp"
    30 #include "utilities/ostream.hpp"
    32 /*
    33  * This class represents a native call path (does not include Java frame)
    34  *
    35  * This class is developed in the context of native memory tracking, it can
    36  * be an useful tool for debugging purpose.
    37  *
    38  * For example, following code should print out native call path:
    39  *
    40  *   ....
    41  *   NativeCallStack here;
    42  *   here.print_on(tty);
    43  *   ....
    44  *
    45  * However, there are a couple of restrictions on this class. If the restrictions are
    46  * not strictly followed, it may break native memory tracking badly.
    47  *
    48  * 1. Number of stack frames to capture, is defined by native memory tracking.
    49  *    This number has impacts on how much memory to be used by native
    50  *    memory tracking.
    51  * 2. The class is strict stack object, no heap or virtual memory can be allocated
    52  *    from it.
    53  */
    54 class NativeCallStack : public StackObj {
    55  private:
    56   address   _stack[NMT_TrackingStackDepth];
    57   int       _hash_value;
    59  public:
    60   NativeCallStack(int toSkip = 0, bool fillStack = false);
    61   NativeCallStack(address* pc, int frameCount);
    64   // if it is an empty stack
    65   inline bool is_empty() const {
    66     return _stack[0] == NULL;
    67   }
    69   // number of stack frames captured
    70   int frames() const;
    72   inline int compare(const NativeCallStack& other) const {
    73     return memcmp(_stack, other._stack, sizeof(_stack));
    74   }
    76   inline bool equals(const NativeCallStack& other) const {
    77     // compare hash values
    78     if (hash() != other.hash()) return false;
    79     // compare each frame
    80     return compare(other) == 0;
    81   }
    83   inline address get_frame(int index) const {
    84     assert(index >= 0 && index < NMT_TrackingStackDepth, "Index out of bound");
    85     return _stack[index];
    86   }
    88   // Hash code. Any better algorithm?
    89   int hash() const;
    91   void print_on(outputStream* out) const;
    92   void print_on(outputStream* out, int indent) const;
    93 };
    95 #endif

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