1 | /* |
---|---|
2 | * Copyright 2013-present Facebook, Inc. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | */ |
16 | |
17 | #include <folly/experimental/exception_tracer/StackTrace.h> |
18 | |
19 | #include <cassert> |
20 | #include <cstdlib> |
21 | #include <new> |
22 | |
23 | #include <folly/experimental/symbolizer/StackTrace.h> |
24 | |
25 | namespace folly { |
26 | namespace exception_tracer { |
27 | |
28 | class StackTraceStack::Node : public StackTrace { |
29 | public: |
30 | static Node* allocate(); |
31 | void deallocate(); |
32 | |
33 | Node* next; |
34 | |
35 | private: |
36 | Node() : next(nullptr) {} |
37 | ~Node() {} |
38 | }; |
39 | |
40 | auto StackTraceStack::Node::allocate() -> Node* { |
41 | // Null pointer on error, please. |
42 | return new (std::nothrow) Node(); |
43 | } |
44 | |
45 | void StackTraceStack::Node::deallocate() { |
46 | delete this; |
47 | } |
48 | |
49 | bool StackTraceStack::pushCurrent() { |
50 | checkGuard(); |
51 | auto node = Node::allocate(); |
52 | if (!node) { |
53 | // cannot allocate memory |
54 | return false; |
55 | } |
56 | |
57 | ssize_t n = folly::symbolizer::getStackTrace(node->addresses, kMaxFrames); |
58 | if (n == -1) { |
59 | node->deallocate(); |
60 | return false; |
61 | } |
62 | node->frameCount = n; |
63 | |
64 | node->next = top_; |
65 | top_ = node; |
66 | return true; |
67 | } |
68 | |
69 | bool StackTraceStack::pop() { |
70 | checkGuard(); |
71 | if (!top_) { |
72 | return false; |
73 | } |
74 | |
75 | auto node = top_; |
76 | top_ = node->next; |
77 | node->deallocate(); |
78 | return true; |
79 | } |
80 | |
81 | bool StackTraceStack::moveTopFrom(StackTraceStack& other) { |
82 | checkGuard(); |
83 | if (!other.top_) { |
84 | return false; |
85 | } |
86 | |
87 | auto node = other.top_; |
88 | other.top_ = node->next; |
89 | node->next = top_; |
90 | top_ = node; |
91 | return true; |
92 | } |
93 | |
94 | void StackTraceStack::clear() { |
95 | checkGuard(); |
96 | while (top_) { |
97 | pop(); |
98 | } |
99 | } |
100 | |
101 | StackTrace* StackTraceStack::top() { |
102 | checkGuard(); |
103 | return top_; |
104 | } |
105 | |
106 | StackTrace* StackTraceStack::next(StackTrace* p) { |
107 | checkGuard(); |
108 | assert(p); |
109 | return static_cast<Node*>(p)->next; |
110 | } |
111 | } // namespace exception_tracer |
112 | } // namespace folly |
113 |