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33 #include "modules/webdatabase/SQLTransactionCoordinator.h"
35 #include "modules/webdatabase/Database.h"
36 #include "modules/webdatabase/SQLTransactionBackend.h"
40 static String getDatabaseIdentifier(SQLTransactionBackend* transaction)
42 Database* database = transaction->database();
44 return database->stringIdentifier();
47 SQLTransactionCoordinator::SQLTransactionCoordinator()
48 : m_isShuttingDown(false)
52 void SQLTransactionCoordinator::trace(Visitor* visitor)
55 visitor->trace(m_coordinationInfoMap);
59 void SQLTransactionCoordinator::processPendingTransactions(CoordinationInfo& info)
61 if (info.activeWriteTransaction || info.pendingTransactions.isEmpty())
64 RefPtrWillBeRawPtr<SQLTransactionBackend> firstPendingTransaction = info.pendingTransactions.first();
65 if (firstPendingTransaction->isReadOnly()) {
67 firstPendingTransaction = info.pendingTransactions.takeFirst();
68 info.activeReadTransactions.add(firstPendingTransaction);
69 firstPendingTransaction->lockAcquired();
70 } while (!info.pendingTransactions.isEmpty() && info.pendingTransactions.first()->isReadOnly());
71 } else if (info.activeReadTransactions.isEmpty()) {
72 info.pendingTransactions.removeFirst();
73 info.activeWriteTransaction = firstPendingTransaction;
74 firstPendingTransaction->lockAcquired();
78 void SQLTransactionCoordinator::acquireLock(SQLTransactionBackend* transaction)
80 ASSERT(!m_isShuttingDown);
82 String dbIdentifier = getDatabaseIdentifier(transaction);
84 CoordinationInfoHeapMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
85 if (coordinationInfoIterator == m_coordinationInfoMap.end()) {
86 // No pending transactions for this DB
87 CoordinationInfo& info = m_coordinationInfoMap.add(dbIdentifier, CoordinationInfo()).storedValue->value;
88 info.pendingTransactions.append(transaction);
89 processPendingTransactions(info);
91 CoordinationInfo& info = coordinationInfoIterator->value;
92 info.pendingTransactions.append(transaction);
93 processPendingTransactions(info);
98 void SQLTransactionCoordinator::releaseLock(SQLTransactionBackend* transaction)
100 if (m_isShuttingDown)
103 String dbIdentifier = getDatabaseIdentifier(transaction);
105 CoordinationInfoHeapMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
106 ASSERT_WITH_SECURITY_IMPLICATION(coordinationInfoIterator != m_coordinationInfoMap.end());
107 CoordinationInfo& info = coordinationInfoIterator->value;
109 if (transaction->isReadOnly()) {
110 ASSERT(info.activeReadTransactions.contains(transaction));
111 info.activeReadTransactions.remove(transaction);
113 ASSERT(info.activeWriteTransaction == transaction);
114 info.activeWriteTransaction = nullptr;
117 processPendingTransactions(info);
120 void SQLTransactionCoordinator::shutdown()
122 // Prevent releaseLock() from accessing / changing the coordinationInfo
123 // while we're shutting down.
124 m_isShuttingDown = true;
126 // Notify all transactions in progress that the database thread is shutting down
127 for (CoordinationInfoHeapMap::iterator coordinationInfoIterator = m_coordinationInfoMap.begin();
128 coordinationInfoIterator != m_coordinationInfoMap.end(); ++coordinationInfoIterator) {
129 CoordinationInfo& info = coordinationInfoIterator->value;
131 // Clean up transactions that have reached "lockAcquired":
132 // Transaction phase 4 cleanup. See comment on "What happens if a
133 // transaction is interrupted?" at the top of SQLTransactionBackend.cpp.
134 if (info.activeWriteTransaction)
135 info.activeWriteTransaction->notifyDatabaseThreadIsShuttingDown();
136 for (WillBeHeapHashSet<RefPtrWillBeMember<SQLTransactionBackend> >::iterator activeReadTransactionsIterator =
137 info.activeReadTransactions.begin();
138 activeReadTransactionsIterator != info.activeReadTransactions.end();
139 ++activeReadTransactionsIterator) {
140 (*activeReadTransactionsIterator)->notifyDatabaseThreadIsShuttingDown();
143 // Clean up transactions that have NOT reached "lockAcquired":
144 // Transaction phase 3 cleanup. See comment on "What happens if a
145 // transaction is interrupted?" at the top of SQLTransactionBackend.cpp.
146 while (!info.pendingTransactions.isEmpty()) {
147 RefPtrWillBeRawPtr<SQLTransactionBackend> transaction = info.pendingTransactions.takeFirst();
148 transaction->notifyDatabaseThreadIsShuttingDown();
152 // Clean up all pending transactions for all databases
153 m_coordinationInfoMap.clear();