1/*
2 * Copyright (C) 2009 Google Inc. All rights reserved.
3 * Copyright (C) 2013 Apple Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 * * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "config.h"
33#include "SQLTransactionCoordinator.h"
34
35#include "Database.h"
36#include "SQLTransaction.h"
37#include "SecurityOrigin.h"
38#include "SecurityOriginData.h"
39#include <wtf/Deque.h>
40#include <wtf/RefPtr.h>
41
42namespace WebCore {
43
44static String getDatabaseIdentifier(SQLTransaction& transaction)
45{
46 return transaction.database().securityOrigin().databaseIdentifier();
47}
48
49SQLTransactionCoordinator::SQLTransactionCoordinator()
50 : m_isShuttingDown(false)
51{
52}
53
54void SQLTransactionCoordinator::processPendingTransactions(CoordinationInfo& info)
55{
56 if (info.activeWriteTransaction || info.pendingTransactions.isEmpty())
57 return;
58
59 RefPtr<SQLTransaction> firstPendingTransaction = info.pendingTransactions.first();
60 if (firstPendingTransaction->isReadOnly()) {
61 do {
62 firstPendingTransaction = info.pendingTransactions.takeFirst();
63 info.activeReadTransactions.add(firstPendingTransaction);
64 firstPendingTransaction->lockAcquired();
65 } while (!info.pendingTransactions.isEmpty() && info.pendingTransactions.first()->isReadOnly());
66 } else if (info.activeReadTransactions.isEmpty()) {
67 info.pendingTransactions.removeFirst();
68 info.activeWriteTransaction = firstPendingTransaction;
69 firstPendingTransaction->lockAcquired();
70 }
71}
72
73void SQLTransactionCoordinator::acquireLock(SQLTransaction& transaction)
74{
75 ASSERT(!m_isShuttingDown);
76
77 String dbIdentifier = getDatabaseIdentifier(transaction);
78
79 CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
80 if (coordinationInfoIterator == m_coordinationInfoMap.end()) {
81 // No pending transactions for this DB
82 coordinationInfoIterator = m_coordinationInfoMap.add(dbIdentifier, CoordinationInfo()).iterator;
83 }
84
85 CoordinationInfo& info = coordinationInfoIterator->value;
86 info.pendingTransactions.append(&transaction);
87 processPendingTransactions(info);
88}
89
90void SQLTransactionCoordinator::releaseLock(SQLTransaction& transaction)
91{
92 if (m_isShuttingDown)
93 return;
94
95 String dbIdentifier = getDatabaseIdentifier(transaction);
96
97 CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
98 ASSERT(coordinationInfoIterator != m_coordinationInfoMap.end());
99 CoordinationInfo& info = coordinationInfoIterator->value;
100
101 if (transaction.isReadOnly()) {
102 ASSERT(info.activeReadTransactions.contains(&transaction));
103 info.activeReadTransactions.remove(&transaction);
104 } else {
105 ASSERT(info.activeWriteTransaction == &transaction);
106 info.activeWriteTransaction = nullptr;
107 }
108
109 processPendingTransactions(info);
110}
111
112void SQLTransactionCoordinator::shutdown()
113{
114 // Prevent releaseLock() from accessing / changing the coordinationInfo
115 // while we're shutting down.
116 m_isShuttingDown = true;
117
118 // Notify all transactions in progress that the database thread is shutting down
119 for (auto& info : m_coordinationInfoMap.values()) {
120 // Clean up transactions that have reached "lockAcquired":
121 // Transaction phase 4 cleanup. See comment on "What happens if a
122 // transaction is interrupted?" at the top of SQLTransactionBackend.cpp.
123 if (info.activeWriteTransaction)
124 info.activeWriteTransaction->notifyDatabaseThreadIsShuttingDown();
125 for (auto& transaction : info.activeReadTransactions)
126 transaction->notifyDatabaseThreadIsShuttingDown();
127
128 // Clean up transactions that have NOT reached "lockAcquired":
129 // Transaction phase 3 cleanup. See comment on "What happens if a
130 // transaction is interrupted?" at the top of SQLTransactionBackend.cpp.
131 while (!info.pendingTransactions.isEmpty()) {
132 RefPtr<SQLTransaction> transaction = info.pendingTransactions.first();
133 transaction->notifyDatabaseThreadIsShuttingDown();
134 }
135 }
136
137 // Clean up all pending transactions for all databases
138 m_coordinationInfoMap.clear();
139}
140
141} // namespace WebCore
142