1 | /* |
2 | * Copyright (C) 2014 Yoav Weiss (yoav@yoav.ws) |
3 | * Copyright (C) 2015 Akamai Technologies Inc. All rights reserved. |
4 | * |
5 | * This library is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU Library General Public |
7 | * License as published by the Free Software Foundation; either |
8 | * version 2 of the License, or (at your option) any later version. |
9 | * |
10 | * This library is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | * Library General Public License for more details. |
14 | * |
15 | * You should have received a copy of the GNU Library General Public License |
16 | * along with this library; see the file COPYING.LIB. If not, write to |
17 | * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
18 | * Boston, MA 02110-1301, USA. |
19 | * |
20 | */ |
21 | |
22 | #include "config.h" |
23 | #include "Microtasks.h" |
24 | |
25 | #include "WorkerGlobalScope.h" |
26 | #include <wtf/MainThread.h> |
27 | #include <wtf/NeverDestroyed.h> |
28 | #include <wtf/SetForScope.h> |
29 | |
30 | namespace WebCore { |
31 | |
32 | void Microtask::removeSelfFromQueue(MicrotaskQueue& queue) |
33 | { |
34 | queue.remove(*this); |
35 | } |
36 | |
37 | MicrotaskQueue::MicrotaskQueue() |
38 | : m_timer(*this, &MicrotaskQueue::timerFired) |
39 | { |
40 | } |
41 | |
42 | MicrotaskQueue::~MicrotaskQueue() = default; |
43 | |
44 | MicrotaskQueue& MicrotaskQueue::mainThreadQueue() |
45 | { |
46 | ASSERT(isMainThread()); |
47 | static NeverDestroyed<MicrotaskQueue> queue; |
48 | return queue; |
49 | } |
50 | |
51 | MicrotaskQueue& MicrotaskQueue::contextQueue(ScriptExecutionContext& context) |
52 | { |
53 | // While main thread has many ScriptExecutionContexts, WorkerGlobalScope and worker thread have |
54 | // one on one correspondence. The lifetime of MicrotaskQueue is aligned to this semantics. |
55 | // While main thread MicrotaskQueue is persistently held, worker's MicrotaskQueue is held by |
56 | // WorkerGlobalScope. |
57 | if (isMainThread()) |
58 | return mainThreadQueue(); |
59 | return downcast<WorkerGlobalScope>(context).microtaskQueue(); |
60 | } |
61 | |
62 | void MicrotaskQueue::append(std::unique_ptr<Microtask>&& task) |
63 | { |
64 | m_microtaskQueue.append(WTFMove(task)); |
65 | |
66 | m_timer.startOneShot(0_s); |
67 | } |
68 | |
69 | void MicrotaskQueue::remove(const Microtask& task) |
70 | { |
71 | for (size_t i = 0; i < m_microtaskQueue.size(); ++i) { |
72 | if (m_microtaskQueue[i].get() == &task) { |
73 | m_microtaskQueue.remove(i); |
74 | return; |
75 | } |
76 | } |
77 | } |
78 | |
79 | void MicrotaskQueue::timerFired() |
80 | { |
81 | performMicrotaskCheckpoint(); |
82 | } |
83 | |
84 | void MicrotaskQueue::performMicrotaskCheckpoint() |
85 | { |
86 | if (m_performingMicrotaskCheckpoint) |
87 | return; |
88 | |
89 | SetForScope<bool> change(m_performingMicrotaskCheckpoint, true); |
90 | |
91 | Vector<std::unique_ptr<Microtask>> toKeep; |
92 | while (!m_microtaskQueue.isEmpty()) { |
93 | Vector<std::unique_ptr<Microtask>> queue = WTFMove(m_microtaskQueue); |
94 | for (auto& task : queue) { |
95 | auto result = task->run(); |
96 | switch (result) { |
97 | case Microtask::Result::Done: |
98 | break; |
99 | case Microtask::Result::KeepInQueue: |
100 | toKeep.append(WTFMove(task)); |
101 | break; |
102 | } |
103 | } |
104 | } |
105 | |
106 | m_microtaskQueue = WTFMove(toKeep); |
107 | } |
108 | |
109 | } // namespace WebCore |
110 | |