nativeCallStack.hpp revision 6881:c346a7739aee
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 */ 24 25#ifndef SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP 26#define SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP 27 28#include "memory/allocation.hpp" 29#include "services/nmtCommon.hpp" 30#include "utilities/ostream.hpp" 31 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 */ 54class NativeCallStack : public StackObj { 55 public: 56 static const NativeCallStack EMPTY_STACK; 57 58 private: 59 address _stack[NMT_TrackingStackDepth]; 60 int _hash_value; 61 62 public: 63 NativeCallStack(int toSkip = 0, bool fillStack = false); 64 NativeCallStack(address* pc, int frameCount); 65 66 67 // if it is an empty stack 68 inline bool is_empty() const { 69 return _stack[0] == NULL; 70 } 71 72 // number of stack frames captured 73 int frames() const; 74 75 inline int compare(const NativeCallStack& other) const { 76 return memcmp(_stack, other._stack, sizeof(_stack)); 77 } 78 79 inline bool equals(const NativeCallStack& other) const { 80 // compare hash values 81 if (hash() != other.hash()) return false; 82 // compare each frame 83 return compare(other) == 0; 84 } 85 86 inline address get_frame(int index) const { 87 assert(index >= 0 && index < NMT_TrackingStackDepth, "Index out of bound"); 88 return _stack[index]; 89 } 90 91 // Hash code. Any better algorithm? 92 int hash() const; 93 94 void print_on(outputStream* out) const; 95 void print_on(outputStream* out, int indent) const; 96}; 97 98#endif 99