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 Computer, 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(DATABASE)
32 #include <wtf/Deque.h>
33 #include <wtf/HashMap.h>
34 #include <wtf/HashSet.h>
35 #include <wtf/MessageQueue.h>
36 #include <wtf/OwnPtr.h>
37 #include <wtf/PassOwnPtr.h>
38 #include <wtf/PassRefPtr.h>
39 #include <wtf/RefPtr.h>
40 #include <wtf/Threading.h>
41 
42 namespace WebCore {
43 
44 class Database;
45 class DatabaseTask;
46 class DatabaseTaskSynchronizer;
47 class Document;
48 class SQLTransactionClient;
49 class SQLTransactionCoordinator;
50 
51 class DatabaseThread : public ThreadSafeRefCounted<DatabaseThread> {
52 public:
create()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(PassOwnPtr<DatabaseTask>);
61     void scheduleImmediateTask(PassOwnPtr<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(Database*);
63 
64     void recordDatabaseOpen(Database*);
65     void recordDatabaseClosed(Database*);
getThreadID()66     ThreadIdentifier getThreadID() { return m_threadID; }
67 
transactionClient()68     SQLTransactionClient* transactionClient() { return m_transactionClient.get(); }
transactionCoordinator()69     SQLTransactionCoordinator* transactionCoordinator() { return m_transactionCoordinator.get(); }
70 
71 private:
72     DatabaseThread();
73 
74     static void* databaseThreadStart(void*);
75     void* databaseThread();
76 
77     Mutex m_threadCreationMutex;
78     ThreadIdentifier m_threadID;
79     RefPtr<DatabaseThread> m_selfRef;
80 
81     MessageQueue<DatabaseTask> m_queue;
82 
83     // This set keeps track of the open databases that have been used on this thread.
84     typedef HashSet<RefPtr<Database> > DatabaseSet;
85     DatabaseSet m_openDatabaseSet;
86 
87     OwnPtr<SQLTransactionClient> m_transactionClient;
88     OwnPtr<SQLTransactionCoordinator> m_transactionCoordinator;
89     DatabaseTaskSynchronizer* m_cleanupSync;
90 };
91 
92 } // namespace WebCore
93 
94 #endif // ENABLE(DATABASE)
95 #endif // DatabaseThread_h
96