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/*
* Copyright (C) 2009 Google Inc. All rights reserved.
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "SQLTransactionCoordinator.h"
#if ENABLE(SQL_DATABASE)
#include "DatabaseBackend.h"
#include "SQLTransactionBackend.h"
#include "SecurityOrigin.h"
#include <wtf/Deque.h>
#include <wtf/HashMap.h>
#include <wtf/HashSet.h>
#include <wtf/RefPtr.h>
namespace WebCore {
static String getDatabaseIdentifier(SQLTransactionBackend* transaction)
{
DatabaseBackend* database = transaction->database();
ASSERT(database);
return database->securityOrigin()->databaseIdentifier();
}
SQLTransactionCoordinator::SQLTransactionCoordinator()
: m_isShuttingDown(false)
{
}
void SQLTransactionCoordinator::processPendingTransactions(CoordinationInfo& info)
{
if (info.activeWriteTransaction || info.pendingTransactions.isEmpty())
return;
RefPtr<SQLTransactionBackend> firstPendingTransaction = info.pendingTransactions.first();
if (firstPendingTransaction->isReadOnly()) {
do {
firstPendingTransaction = info.pendingTransactions.takeFirst();
info.activeReadTransactions.add(firstPendingTransaction);
firstPendingTransaction->lockAcquired();
} while (!info.pendingTransactions.isEmpty() && info.pendingTransactions.first()->isReadOnly());
} else if (info.activeReadTransactions.isEmpty()) {
info.pendingTransactions.removeFirst();
info.activeWriteTransaction = firstPendingTransaction;
firstPendingTransaction->lockAcquired();
}
}
void SQLTransactionCoordinator::acquireLock(SQLTransactionBackend* transaction)
{
ASSERT(!m_isShuttingDown);
String dbIdentifier = getDatabaseIdentifier(transaction);
CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
if (coordinationInfoIterator == m_coordinationInfoMap.end()) {
// No pending transactions for this DB
coordinationInfoIterator = m_coordinationInfoMap.add(dbIdentifier, CoordinationInfo()).iterator;
}
CoordinationInfo& info = coordinationInfoIterator->value;
info.pendingTransactions.append(transaction);
processPendingTransactions(info);
}
void SQLTransactionCoordinator::releaseLock(SQLTransactionBackend* transaction)
{
if (m_isShuttingDown)
return;
String dbIdentifier = getDatabaseIdentifier(transaction);
CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.find(dbIdentifier);
ASSERT(coordinationInfoIterator != m_coordinationInfoMap.end());
CoordinationInfo& info = coordinationInfoIterator->value;
if (transaction->isReadOnly()) {
ASSERT(info.activeReadTransactions.contains(transaction));
info.activeReadTransactions.remove(transaction);
} else {
ASSERT(info.activeWriteTransaction == transaction);
info.activeWriteTransaction = 0;
}
processPendingTransactions(info);
}
void SQLTransactionCoordinator::shutdown()
{
// Prevent releaseLock() from accessing / changing the coordinationInfo
// while we're shutting down.
m_isShuttingDown = true;
// Notify all transactions in progress that the database thread is shutting down
for (CoordinationInfoMap::iterator coordinationInfoIterator = m_coordinationInfoMap.begin();
coordinationInfoIterator != m_coordinationInfoMap.end(); ++coordinationInfoIterator) {
CoordinationInfo& info = coordinationInfoIterator->value;
// Clean up transactions that have reached "lockAcquired":
// Transaction phase 4 cleanup. See comment on "What happens if a
// transaction is interrupted?" at the top of SQLTransactionBackend.cpp.
if (info.activeWriteTransaction)
info.activeWriteTransaction->notifyDatabaseThreadIsShuttingDown();
for (HashSet<RefPtr<SQLTransactionBackend> >::iterator activeReadTransactionsIterator =
info.activeReadTransactions.begin();
activeReadTransactionsIterator != info.activeReadTransactions.end();
++activeReadTransactionsIterator) {
(*activeReadTransactionsIterator)->notifyDatabaseThreadIsShuttingDown();
}
// Clean up transactions that have NOT reached "lockAcquired":
// Transaction phase 3 cleanup. See comment on "What happens if a
// transaction is interrupted?" at the top of SQLTransactionBackend.cpp.
while (!info.pendingTransactions.isEmpty()) {
RefPtr<SQLTransactionBackend> transaction = info.pendingTransactions.first();
transaction->notifyDatabaseThreadIsShuttingDown();
}
}
// Clean up all pending transactions for all databases
m_coordinationInfoMap.clear();
}
} // namespace WebCore
#endif // ENABLE(SQL_DATABASE)
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