2 * Copyright (C) 2011 Google Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #ifndef V8RecursionScope_h
32 #define V8RecursionScope_h
34 #include "bindings/v8/V8PerIsolateData.h"
35 #include "core/dom/ExecutionContext.h"
36 #include "core/dom/ScriptForbiddenScope.h"
37 #include "wtf/Noncopyable.h"
42 // C++ calls into script contexts which are "owned" by WebKit (created in a
43 // process where WebKit.cpp initializes v8) must declare their type:
45 // 1. Calls into page/author script from a frame
46 // 2. Calls into page/author script from a worker
47 // 3. Calls into internal script (typically setup/teardown work)
49 // Debug-time checking of this is enforced via this class.
51 // Calls of type (1) should generally go through ScriptController, as inspector
52 // instrumentation is needed. ScriptController allocates V8RecursionScope for you.
53 // Calls of type (2) should always stack-allocate a V8RecursionScope in the same
54 // block as the call into script. Calls of type (3) should stack allocate a
55 // V8RecursionScope::MicrotaskSuppression -- this skips work that is spec'd to
56 // happen at the end of the outer-most script stack frame of calls into page script:
58 // http://www.whatwg.org/specs/web-apps/current-work/#perform-a-microtask-checkpoint
59 class V8RecursionScope {
60 WTF_MAKE_NONCOPYABLE(V8RecursionScope);
62 V8RecursionScope(v8::Isolate* isolate, ExecutionContext* context)
64 , m_executionContext(*context)
66 V8PerIsolateData::from(m_isolate)->incrementRecursionLevel();
67 ASSERT(!ScriptForbiddenScope::isScriptForbidden());
68 // If you want V8 to autorun microtasks, this class needs to have a
69 // v8::Isolate::SuppressMicrotaskExecutionScope member.
70 ASSERT(!isolate->WillAutorunMicrotasks());
75 if (!V8PerIsolateData::from(m_isolate)->decrementRecursionLevel())
76 didLeaveScriptContext();
79 static int recursionLevel(v8::Isolate* isolate)
81 return V8PerIsolateData::from(isolate)->recursionLevel();
85 static bool properlyUsed(v8::Isolate* isolate)
87 return recursionLevel(isolate) > 0 || V8PerIsolateData::from(isolate)->internalScriptRecursionLevel() > 0;
91 class MicrotaskSuppression {
93 MicrotaskSuppression(v8::Isolate* isolate)
98 ASSERT(!ScriptForbiddenScope::isScriptForbidden());
100 V8PerIsolateData::from(m_isolate)->incrementInternalScriptRecursionLevel();
104 ~MicrotaskSuppression()
107 V8PerIsolateData::from(m_isolate)->decrementInternalScriptRecursionLevel();
113 v8::Isolate* m_isolate;
118 void didLeaveScriptContext();
120 v8::Isolate* m_isolate;
121 ExecutionContext& m_executionContext;
124 } // namespace WebCore
126 #endif // V8RecursionScope_h