1/*
2 * Copyright (c) 2014, 2016, 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#include "precompiled.hpp"
26#include "runtime/os.hpp"
27#include "utilities/globalDefinitions.hpp"
28#include "utilities/nativeCallStack.hpp"
29
30const NativeCallStack NativeCallStack::EMPTY_STACK(0, false);
31
32NativeCallStack::NativeCallStack(int toSkip, bool fillStack) :
33  _hash_value(0) {
34
35  if (fillStack) {
36    // We need to skip the NativeCallStack::NativeCallStack frame if a tail call is NOT used
37    // to call os::get_native_stack. A tail call is used if _NMT_NOINLINE_ is not defined
38    // (which means this is not a slowdebug build), and we are on 64-bit (except Windows).
39    // This is not necessarily a rule, but what has been obvserved to date.
40#define TAIL_CALL (!defined(_NMT_NOINLINE_) && !defined(WINDOWS) && defined(_LP64))
41#if !TAIL_CALL
42    toSkip++;
43#if (defined(_NMT_NOINLINE_) && defined(BSD) && defined(_LP64))
44    // Mac OS X slowdebug builds have this odd behavior where NativeCallStack::NativeCallStack
45    // appears as two frames, so we need to skip an extra frame.
46    toSkip++;
47#endif
48#endif
49    os::get_native_stack(_stack, NMT_TrackingStackDepth, toSkip);
50  } else {
51    for (int index = 0; index < NMT_TrackingStackDepth; index ++) {
52      _stack[index] = NULL;
53    }
54  }
55}
56
57NativeCallStack::NativeCallStack(address* pc, int frameCount) {
58  int frameToCopy = (frameCount < NMT_TrackingStackDepth) ?
59    frameCount : NMT_TrackingStackDepth;
60  int index;
61  for (index = 0; index < frameToCopy; index ++) {
62    _stack[index] = pc[index];
63  }
64  for (; index < NMT_TrackingStackDepth; index ++) {
65    _stack[index] = NULL;
66  }
67  _hash_value = 0;
68}
69
70// number of stack frames captured
71int NativeCallStack::frames() const {
72  int index;
73  for (index = 0; index < NMT_TrackingStackDepth; index ++) {
74    if (_stack[index] == NULL) {
75      break;
76    }
77  }
78  return index;
79}
80
81// Hash code. Any better algorithm?
82unsigned int NativeCallStack::hash() const {
83  uintptr_t hash_val = _hash_value;
84  if (hash_val == 0) {
85    for (int index = 0; index < NMT_TrackingStackDepth; index++) {
86      if (_stack[index] == NULL) break;
87      hash_val += (uintptr_t)_stack[index];
88    }
89
90    NativeCallStack* p = const_cast<NativeCallStack*>(this);
91    p->_hash_value = (unsigned int)(hash_val & 0xFFFFFFFF);
92  }
93  return _hash_value;
94}
95
96void NativeCallStack::print_on(outputStream* out) const {
97  print_on(out, 0);
98}
99
100// Decode and print this call path
101void NativeCallStack::print_on(outputStream* out, int indent) const {
102  address pc;
103  char    buf[1024];
104  int     offset;
105  if (is_empty()) {
106    for (int index = 0; index < indent; index ++) out->print(" ");
107    out->print("[BOOTSTRAP]");
108  } else {
109    for (int frame = 0; frame < NMT_TrackingStackDepth; frame ++) {
110      pc = get_frame(frame);
111      if (pc == NULL) break;
112      // Print indent
113      for (int index = 0; index < indent; index ++) out->print(" ");
114      if (os::dll_address_to_function_name(pc, buf, sizeof(buf), &offset)) {
115        out->print_cr("[" PTR_FORMAT "] %s+0x%x", p2i(pc), buf, offset);
116      } else {
117        out->print_cr("[" PTR_FORMAT "]", p2i(pc));
118      }
119    }
120  }
121}
122
123