1/*
2 * Copyright (C) 2014 Google 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 are
6 * met:
7 *
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
13 * distribution.
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.
17 *
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.
29 */
30
31#ifndef PendingGCRunner_h
32#define PendingGCRunner_h
33
34#include "platform/heap/ThreadState.h"
35#include "public/platform/WebThread.h"
36
37namespace blink {
38
39class PendingGCRunner : public blink::WebThread::TaskObserver {
40public:
41    PendingGCRunner() : m_nesting(0) { }
42
43    ~PendingGCRunner()
44    {
45        // m_nesting can be 1 if this was unregistered in a task and
46        // didProcessTask was not called.
47        ASSERT(!m_nesting || m_nesting == 1);
48    }
49
50    virtual void willProcessTask()
51    {
52        m_nesting++;
53    }
54
55    virtual void didProcessTask()
56    {
57        // In the production code WebKit::initialize is called from inside the
58        // message loop so we can get didProcessTask() without corresponding
59        // willProcessTask once. This is benign.
60        if (m_nesting)
61            m_nesting--;
62
63        blink::ThreadState* state = blink::ThreadState::current();
64        state->safePoint(m_nesting ? blink::ThreadState::HeapPointersOnStack : blink::ThreadState::NoHeapPointersOnStack);
65    }
66
67private:
68    int m_nesting;
69};
70
71}
72
73#endif
74