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/*
* Copyright (C) 2009 Google 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"
#include "CString.h"
#include "Database.h"
#include "SQLTransaction.h"
#include <wtf/Deque.h>
#include <wtf/HashMap.h>
#include <wtf/RefPtr.h>
namespace WebCore {
static String getDatabaseIdentifier(SQLTransaction* transaction)
{
Database* database = transaction->database();
ASSERT(database);
return database->stringIdentifier();
}
void SQLTransactionCoordinator::acquireLock(SQLTransaction* transaction)
{
String dbIdentifier = getDatabaseIdentifier(transaction);
TransactionsHashMap::iterator it = m_pendingTransactions.find(dbIdentifier);
if (it == m_pendingTransactions.end()) {
// No pending transactions for this DB
TransactionsQueue pendingTransactions;
pendingTransactions.append(transaction);
m_pendingTransactions.add(dbIdentifier, pendingTransactions);
// Start the transaction
transaction->lockAcquired();
} else {
// Another transaction is running on this DB; put this one in the queue
TransactionsQueue& pendingTransactions = it->second;
pendingTransactions.append(transaction);
}
}
void SQLTransactionCoordinator::releaseLock(SQLTransaction* transaction)
{
if (m_pendingTransactions.isEmpty())
return;
String dbIdentifier = getDatabaseIdentifier(transaction);
TransactionsHashMap::iterator it = m_pendingTransactions.find(dbIdentifier);
ASSERT(it != m_pendingTransactions.end());
TransactionsQueue& pendingTransactions = it->second;
ASSERT(!pendingTransactions.isEmpty());
// 'transaction' should always be the first transaction in this queue
ASSERT(pendingTransactions.first().get() == transaction);
// Remove 'transaction' from the queue of pending transactions
pendingTransactions.removeFirst();
if (pendingTransactions.isEmpty()) {
// No more pending transactions; delete dbIdentifier's queue
m_pendingTransactions.remove(it);
} else {
// We have more pending transactions; start the next one
pendingTransactions.first()->lockAcquired();
}
}
void SQLTransactionCoordinator::shutdown()
{
// Clean up all pending transactions for all databases
m_pendingTransactions.clear();
}
}
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