third_party/WebKit/Source/modules/webdatabase/DatabaseThread.h

/*
 * Copyright (C) 2007, 2008 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:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 */
#ifndef DatabaseThread_h
#define DatabaseThread_h

#include "platform/WebThreadSupportingGC.h"
#include "platform/heap/Handle.h"
#include "wtf/HashMap.h"
#include "wtf/ThreadingPrimitives.h"
#include <memory>

namespace blink {

class Database;
class DatabaseTask;
class SQLTransactionClient;
class SQLTransactionCoordinator;
class WaitableEvent;

class DatabaseThread : public GarbageCollectedFinalized<DatabaseThread> {
 public:
  static DatabaseThread* create() { return new DatabaseThread; }
  ~DatabaseThread();
  DECLARE_TRACE();

  // Callable only from the main thread.
  void start();
  void terminate();

  // Callable from the main thread or the database thread.
  void scheduleTask(std::unique_ptr<DatabaseTask>);
  bool isDatabaseThread() const;

  // Callable only from the database thread.
  void recordDatabaseOpen(Database*);
  void recordDatabaseClosed(Database*);
  bool isDatabaseOpen(Database*);

  SQLTransactionClient* transactionClient() {
    return m_transactionClient.get();
  }
  SQLTransactionCoordinator* transactionCoordinator() {
    return m_transactionCoordinator.get();
  }

 private:
  DatabaseThread();

  void setupDatabaseThread();
  void cleanupDatabaseThread();
  void cleanupDatabaseThreadCompleted();

  std::unique_ptr<WebThreadSupportingGC> m_thread;

  // This set keeps track of the open databases that have been used on this
  // thread.  This must be updated in the database thread though it is
  // constructed and destructed in the context thread.
  HashSet<CrossThreadPersistent<Database>> m_openDatabaseSet;

  std::unique_ptr<SQLTransactionClient> m_transactionClient;
  CrossThreadPersistent<SQLTransactionCoordinator> m_transactionCoordinator;
  WaitableEvent* m_cleanupSync;

  Mutex m_terminationRequestedMutex;
  bool m_terminationRequested;
};

}  // namespace blink

#endif  // DatabaseThread_h