cef/include/cef_task.h

// Copyright (c) 2013 Marshall A. Greenblatt. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
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// ---------------------------------------------------------------------------
//
// The contents of this file must follow a specific format in order to
// support the CEF translator tool. See the translator.README.txt file in the
// tools directory for more information.
//

#ifndef CEF_INCLUDE_CEF_TASK_H_
#define CEF_INCLUDE_CEF_TASK_H_

#include "include/cef_base.h"

typedef cef_thread_id_t CefThreadId;

///
/// Implement this interface for asynchronous task execution. If the task is
/// posted successfully and if the associated message loop is still running then
/// the Execute() method will be called on the target thread. If the task fails
/// to post then the task object may be destroyed on the source thread instead
/// of the target thread. For this reason be cautious when performing work in
/// the task object destructor.
///
/*--cef(source=client,no_debugct_check)--*/
class CefTask : public virtual CefBaseRefCounted {
 public:
  ///
  /// Method that will be executed on the target thread.
  ///
  /*--cef()--*/
  virtual void Execute() = 0;
};

///
/// Class that asynchronously executes tasks on the associated thread. It is
/// safe to call the methods of this class on any thread.
///
/// CEF maintains multiple internal threads that are used for handling different
/// types of tasks in different processes. The cef_thread_id_t definitions in
/// cef_types.h list the common CEF threads. Task runners are also available for
/// other CEF threads as appropriate (for example, V8 WebWorker threads).
///
/*--cef(source=library)--*/
class CefTaskRunner : public virtual CefBaseRefCounted {
 public:
  ///
  /// Returns the task runner for the current thread. Only CEF threads will have
  /// task runners. An empty reference will be returned if this method is called
  /// on an invalid thread.
  ///
  /*--cef()--*/
  static CefRefPtr<CefTaskRunner> GetForCurrentThread();

  ///
  /// Returns the task runner for the specified CEF thread.
  ///
  /*--cef()--*/
  static CefRefPtr<CefTaskRunner> GetForThread(CefThreadId threadId);

  ///
  /// Returns true if this object is pointing to the same task runner as |that|
  /// object.
  ///
  /*--cef()--*/
  virtual bool IsSame(CefRefPtr<CefTaskRunner> that) = 0;

  ///
  /// Returns true if this task runner belongs to the current thread.
  ///
  /*--cef()--*/
  virtual bool BelongsToCurrentThread() = 0;

  ///
  /// Returns true if this task runner is for the specified CEF thread.
  ///
  /*--cef()--*/
  virtual bool BelongsToThread(CefThreadId threadId) = 0;

  ///
  /// Post a task for execution on the thread associated with this task runner.
  /// Execution will occur asynchronously.
  ///
  /*--cef()--*/
  virtual bool PostTask(CefRefPtr<CefTask> task) = 0;

  ///
  /// Post a task for delayed execution on the thread associated with this task
  /// runner. Execution will occur asynchronously. Delayed tasks are not
  /// supported on V8 WebWorker threads and will be executed without the
  /// specified delay.
  ///
  /*--cef()--*/
  virtual bool PostDelayedTask(CefRefPtr<CefTask> task, int64 delay_ms) = 0;
};

///
/// Returns true if called on the specified thread. Equivalent to using
/// CefTaskRunner::GetForThread(threadId)->BelongsToCurrentThread().
///
/*--cef()--*/
bool CefCurrentlyOn(CefThreadId threadId);

///
/// Post a task for execution on the specified thread. Equivalent to
/// using CefTaskRunner::GetForThread(threadId)->PostTask(task).
///
/*--cef()--*/
bool CefPostTask(CefThreadId threadId, CefRefPtr<CefTask> task);

///
/// Post a task for delayed execution on the specified thread. Equivalent to
/// using CefTaskRunner::GetForThread(threadId)->PostDelayedTask(task,
/// delay_ms).
///
/*--cef()--*/
bool CefPostDelayedTask(CefThreadId threadId,
                        CefRefPtr<CefTask> task,
                        int64 delay_ms);

#endif  // CEF_INCLUDE_CEF_TASK_H_