1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "AsyncStackTrace.h"
28
29#include "ScriptCallStack.h"
30#include <wtf/Ref.h>
31
32namespace Inspector {
33
34Ref<AsyncStackTrace> AsyncStackTrace::create(Ref<ScriptCallStack>&& callStack, bool singleShot, RefPtr<AsyncStackTrace> parent)
35{
36 ASSERT(callStack->size());
37 return adoptRef(*new AsyncStackTrace(WTFMove(callStack), singleShot, WTFMove(parent)));
38}
39
40AsyncStackTrace::AsyncStackTrace(Ref<ScriptCallStack>&& callStack, bool singleShot, RefPtr<AsyncStackTrace> parent)
41 : m_callStack(WTFMove(callStack))
42 , m_parent(parent)
43 , m_singleShot(singleShot)
44{
45 if (m_parent)
46 m_parent->m_childCount++;
47}
48
49AsyncStackTrace::~AsyncStackTrace()
50{
51 if (m_parent)
52 remove();
53 ASSERT(!m_childCount);
54}
55
56bool AsyncStackTrace::isPending() const
57{
58 return m_state == State::Pending;
59}
60
61bool AsyncStackTrace::isLocked() const
62{
63 return m_state == State::Pending || m_state == State::Active || m_childCount > 1;
64}
65
66void AsyncStackTrace::willDispatchAsyncCall(size_t maxDepth)
67{
68 ASSERT(m_state == State::Pending);
69 m_state = State::Active;
70
71 truncate(maxDepth);
72}
73
74void AsyncStackTrace::didDispatchAsyncCall()
75{
76 ASSERT(m_state == State::Active || m_state == State::Canceled);
77
78 if (m_state == State::Active && !m_singleShot) {
79 m_state = State::Pending;
80 return;
81 }
82
83 m_state = State::Dispatched;
84
85 if (!m_childCount)
86 remove();
87}
88
89void AsyncStackTrace::didCancelAsyncCall()
90{
91 if (m_state == State::Canceled)
92 return;
93
94 if (m_state == State::Pending && !m_childCount)
95 remove();
96
97 m_state = State::Canceled;
98}
99
100RefPtr<Protocol::Console::StackTrace> AsyncStackTrace::buildInspectorObject() const
101{
102 RefPtr<Protocol::Console::StackTrace> topStackTrace;
103 RefPtr<Protocol::Console::StackTrace> previousStackTrace;
104
105 auto* stackTrace = this;
106 while (stackTrace) {
107 auto& callStack = stackTrace->m_callStack;
108 ASSERT(callStack->size());
109
110 auto protocolObject = Protocol::Console::StackTrace::create()
111 .setCallFrames(callStack->buildInspectorArray())
112 .release();
113
114 if (stackTrace->m_truncated)
115 protocolObject->setTruncated(true);
116 if (callStack->at(0).isNative())
117 protocolObject->setTopCallFrameIsBoundary(true);
118
119 if (!topStackTrace)
120 topStackTrace = protocolObject.ptr();
121
122 if (previousStackTrace)
123 previousStackTrace->setParentStackTrace(protocolObject.ptr());
124
125 previousStackTrace = WTFMove(protocolObject);
126 stackTrace = stackTrace->m_parent.get();
127 }
128
129 return topStackTrace;
130}
131
132void AsyncStackTrace::truncate(size_t maxDepth)
133{
134 AsyncStackTrace* lastUnlockedAncestor = nullptr;
135 size_t depth = 0;
136
137 auto* newStackTraceRoot = this;
138 while (newStackTraceRoot) {
139 depth += newStackTraceRoot->m_callStack->size();
140 if (depth >= maxDepth)
141 break;
142
143 auto* parent = newStackTraceRoot->m_parent.get();
144 if (!lastUnlockedAncestor && parent && parent->isLocked())
145 lastUnlockedAncestor = newStackTraceRoot;
146
147 newStackTraceRoot = parent;
148 }
149
150 if (!newStackTraceRoot || !newStackTraceRoot->m_parent)
151 return;
152
153 if (!lastUnlockedAncestor) {
154 // No locked nodes belong to the trace. The subtree at the new root
155 // is moved to a new tree, and marked as truncated if necessary.
156 newStackTraceRoot->m_truncated = true;
157 newStackTraceRoot->remove();
158 return;
159 }
160
161 // The new root has a locked descendent. Since truncating a stack trace
162 // cannot mutate locked nodes or their ancestors, a new tree is created by
163 // cloning the locked portion of the trace (the path from the locked node
164 // to the new root). The subtree rooted at the last unlocked ancestor is
165 // then appended to the new tree.
166 auto* previousNode = lastUnlockedAncestor;
167
168 // The subtree being truncated must be removed from it's parent before
169 // updating its parent pointer chain.
170 RefPtr<AsyncStackTrace> sourceNode = lastUnlockedAncestor->m_parent;
171 lastUnlockedAncestor->remove();
172
173 while (sourceNode) {
174 previousNode->m_parent = AsyncStackTrace::create(sourceNode->m_callStack.copyRef(), true, nullptr);
175 previousNode->m_parent->m_childCount = 1;
176 previousNode = previousNode->m_parent.get();
177
178 if (sourceNode.get() == newStackTraceRoot)
179 break;
180
181 sourceNode = sourceNode->m_parent;
182 }
183
184 previousNode->m_truncated = true;
185}
186
187void AsyncStackTrace::remove()
188{
189 if (!m_parent)
190 return;
191
192 ASSERT(m_parent->m_childCount);
193 m_parent->m_childCount--;
194 m_parent = nullptr;
195}
196
197} // namespace Inspector
198