1/*
2 * Copyright (C) 2007, 2008 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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28#ifndef DatabaseThread_h
29#define DatabaseThread_h
30
31#if ENABLE(SQL_DATABASE)
32
33#include <memory>
34#include <wtf/Deque.h>
35#include <wtf/HashMap.h>
36#include <wtf/HashSet.h>
37#include <wtf/MessageQueue.h>
38#include <wtf/PassRefPtr.h>
39#include <wtf/RefPtr.h>
40#include <wtf/Threading.h>
41
42namespace WebCore {
43
44class DatabaseBackend;
45class DatabaseTask;
46class DatabaseTaskSynchronizer;
47class Document;
48class SQLTransactionClient;
49class SQLTransactionCoordinator;
50
51class DatabaseThread : public ThreadSafeRefCounted<DatabaseThread> {
52public:
53    static PassRefPtr<DatabaseThread> create() { return adoptRef(new DatabaseThread); }
54    ~DatabaseThread();
55
56    bool start();
57    void requestTermination(DatabaseTaskSynchronizer* cleanupSync);
58    bool terminationRequested(DatabaseTaskSynchronizer* taskSynchronizer = 0) const;
59
60    void scheduleTask(std::unique_ptr<DatabaseTask>);
61    void scheduleImmediateTask(std::unique_ptr<DatabaseTask>); // This just adds the task to the front of the queue - the caller needs to be extremely careful not to create deadlocks when waiting for completion.
62    void unscheduleDatabaseTasks(DatabaseBackend*);
63
64    void recordDatabaseOpen(DatabaseBackend*);
65    void recordDatabaseClosed(DatabaseBackend*);
66    ThreadIdentifier getThreadID() { return m_threadID; }
67
68    SQLTransactionClient* transactionClient() { return m_transactionClient.get(); }
69    SQLTransactionCoordinator* transactionCoordinator() { return m_transactionCoordinator.get(); }
70
71#if PLATFORM(IOS)
72    void setPaused(bool);
73    void handlePausedQueue();
74#endif
75
76private:
77    DatabaseThread();
78
79    static void databaseThreadStart(void*);
80    void databaseThread();
81
82    Mutex m_threadCreationMutex;
83    ThreadIdentifier m_threadID;
84    RefPtr<DatabaseThread> m_selfRef;
85
86    MessageQueue<DatabaseTask> m_queue;
87#if PLATFORM(IOS)
88    MessageQueue<DatabaseTask> m_pausedQueue;
89    Mutex m_pausedMutex;
90    volatile bool m_paused;
91#endif
92
93    // This set keeps track of the open databases that have been used on this thread.
94    typedef HashSet<RefPtr<DatabaseBackend>> DatabaseSet;
95    DatabaseSet m_openDatabaseSet;
96
97    std::unique_ptr<SQLTransactionClient> m_transactionClient;
98    std::unique_ptr<SQLTransactionCoordinator> m_transactionCoordinator;
99    DatabaseTaskSynchronizer* m_cleanupSync;
100};
101
102} // namespace WebCore
103
104#endif // ENABLE(SQL_DATABASE)
105#endif // DatabaseThread_h
106