The BackgroundTaskManager is the central singleton that manages running background tasks. More...

#include <mlBackgroundTaskManager.h>

Classes
class	Observer
	Abstract interface to observe the BackgroundTaskManager. More...

Public Member Functions
BackgroundTaskHandle	runTask (BackgroundTask *task)
	Runs the given task.

int	totalTaskCount ()
	Returns the number of queued and running tasks.

void	getStatusInformation (std::vector< BackgroundTaskStatusInformation > &infos)
	Gets a snapshot of the state of all background tasks, representing the consistent status at the time of calling this function.

void	sendMessageToGUI (BackgroundTaskMessage *message)
	Sends the given message asynchronously to the GUI thread.

void	sendMessageToTask (BackgroundTask task, BackgroundTaskMessage message)
	Sends the given message asynchronously to the worker thread of the task.

bool	hasSynchronousTask () const
	Returns true if the manager is currently processing a synchronous task.

bool	processPendingMessages ()
	Processes all pending messages (will not block and may only be called from the GUI thread, typically from an idle timer).

void	cancelPendingRequestsForTask (BackgroundTask *task)
	Cancels pending requests for a given task.

void	removeMessagesForReceiver (BackgroundTaskMessageReceiver *receiver)
	Removes all messages for receiver from the GUI message queue.

void	addObserver (Observer *observer)
	Adds an observer (the ownership stays with the caller).

void	removeObserver (Observer *observer)
	Removes an observer (the ownership stays with the caller).

PageRequestProcessor &	getPageRequestProcessor ()
	Returns instance of the page request processor (TODO: this will probably move into the ML host!).

void	setBackgroundTaskScheduleProcessPendingMessagesCB (BackgroundTaskScheduleProcessPendingMessagesCB cb, void userData)
	Sets the callback that will be called from any worker thread when a call of processPendingMessages() on the GUI thread is required.

void	getBackgroundTaskScheduleProcessPendingMessagesCB (BackgroundTaskScheduleProcessPendingMessagesCB cb, void userData)
	Gets the currently set callback.

bool	supportsAsynchronousTasks ()
	Returns whether asynchronous tasks are supported, which is the case if setBackgroundTaskScheduleProcessPendingMessagesCB was called with a non-NULL callback.

Static Public Member Functions
static BackgroundTaskManager &	self ()
	Returns the global singleton.

static void	init ()
	Initializes the background task manager.

static void	cleanup ()
	Cleans up the background task manager.

static bool	ensureGUIThread ()
	Returns `true` if the current thread is the GUI thread.

static bool	ensureWorkerThread ()
	Returns `true` if the current thread is not the GUI thread and is thus a worker thread.

Protected Member Functions
MLuint32	getUniqueTaskId ()
	Returns new unique id of a task.

void	sendTaskAdded (BackgroundTask *task)
	Sends a `task` that is added to the observers.

void	sendTaskRemoved (BackgroundTask *task)
	Sends a `task` that is removed from the observers.

void	sendTaskStatusUpdated ()
	Sends that a task's status is updated to the observers.

void	removeTaskFromQueueAndSendTaskFinished (BackgroundTask *task)
	Removes a `task` if it was queued.

BackgroundTask *	waitForTask ()
	Waits for a new task and returns the new task from the queue.

void	sendTaskFinishedMessage (BackgroundTask *task)
	Called by worker threads when a task is finished.

Friends
struct	BackgroundTaskManagerWorkerFunc

class	BackgroundTaskFinishedMessage

class	BackgroundTask

class	BackgroundTaskManagerPrivate

Detailed Description

The BackgroundTaskManager is the central singleton that manages running background tasks.

Definition at line 53 of file mlBackgroundTaskManager.h.

Member Function Documentation

◆ addObserver()

void ml::BackgroundTaskManager::addObserver ( Observer * observer )

Adds an observer (the ownership stays with the caller).

◆ cancelPendingRequestsForTask()

void ml::BackgroundTaskManager::cancelPendingRequestsForTask ( BackgroundTask * task )

Cancels pending requests for a given task.

◆ cleanup()

static void ml::BackgroundTaskManager::cleanup ( )

static

Cleans up the background task manager.

◆ ensureGUIThread()

static bool ml::BackgroundTaskManager::ensureGUIThread ( )

static

Returns true if the current thread is the GUI thread.

◆ ensureWorkerThread()

static bool ml::BackgroundTaskManager::ensureWorkerThread ( )

static

Returns true if the current thread is not the GUI thread and is thus a worker thread.

Note: in synchronous mode, this will always return true. Do not use it to decide on the code path; use ensureGUIThread instead.

◆ getBackgroundTaskScheduleProcessPendingMessagesCB()

void ml::BackgroundTaskManager::getBackgroundTaskScheduleProcessPendingMessagesCB	(	BackgroundTaskScheduleProcessPendingMessagesCB **	cb,
		void **	userData )

Gets the currently set callback.

◆ getPageRequestProcessor()

PageRequestProcessor & ml::BackgroundTaskManager::getPageRequestProcessor ( )

Returns instance of the page request processor (TODO: this will probably move into the ML host!).

◆ getStatusInformation()

void ml::BackgroundTaskManager::getStatusInformation ( std::vector< BackgroundTaskStatusInformation > & infos )

Gets a snapshot of the state of all background tasks, representing the consistent status at the time of calling this function.

◆ getUniqueTaskId()

MLuint32 ml::BackgroundTaskManager::getUniqueTaskId ( )

protected

Returns new unique id of a task.

This is thread-safe.

◆ hasSynchronousTask()

bool ml::BackgroundTaskManager::hasSynchronousTask ( ) const

inline

Returns true if the manager is currently processing a synchronous task.

Definition at line 96 of file mlBackgroundTaskManager.h.

◆ init()

static void ml::BackgroundTaskManager::init ( )

static

Initializes the background task manager.

◆ processPendingMessages()

bool ml::BackgroundTaskManager::processPendingMessages ( )

Processes all pending messages (will not block and may only be called from the GUI thread, typically from an idle timer).

Returns whether more work is available.

◆ removeMessagesForReceiver()

void ml::BackgroundTaskManager::removeMessagesForReceiver ( BackgroundTaskMessageReceiver * receiver )

Removes all messages for receiver from the GUI message queue.

◆ removeObserver()

void ml::BackgroundTaskManager::removeObserver ( Observer * observer )

Removes an observer (the ownership stays with the caller).

◆ removeTaskFromQueueAndSendTaskFinished()

void ml::BackgroundTaskManager::removeTaskFromQueueAndSendTaskFinished ( BackgroundTask * task )

protected

Removes a task if it was queued.

◆ runTask()

BackgroundTaskHandle ml::BackgroundTaskManager::runTask ( BackgroundTask * task )

Runs the given task.

The ownership of the task is transfered to the task manager. Do not delete the task yourself! Only call this from the GUI thread!

◆ self()

static BackgroundTaskManager & ml::BackgroundTaskManager::self ( )

static

Returns the global singleton.

◆ sendMessageToGUI()

void ml::BackgroundTaskManager::sendMessageToGUI ( BackgroundTaskMessage * message )

Sends the given message asynchronously to the GUI thread.

The message ownership is passed to the manager. Do not delete it yourself!

◆ sendMessageToTask()

void ml::BackgroundTaskManager::sendMessageToTask	(	BackgroundTask *	task,
		BackgroundTaskMessage *	message )

Sends the given message asynchronously to the worker thread of the task.

The message ownership is passed to the manager. Do not delete it yourself!

◆ sendTaskAdded()

void ml::BackgroundTaskManager::sendTaskAdded ( BackgroundTask * task )

protected

Sends a task that is added to the observers.

◆ sendTaskFinishedMessage()

void ml::BackgroundTaskManager::sendTaskFinishedMessage ( BackgroundTask * task )

protected

Called by worker threads when a task is finished.

◆ sendTaskRemoved()

void ml::BackgroundTaskManager::sendTaskRemoved ( BackgroundTask * task )

protected

Sends a task that is removed from the observers.

◆ sendTaskStatusUpdated()

void ml::BackgroundTaskManager::sendTaskStatusUpdated ( )

protected

Sends that a task's status is updated to the observers.

◆ setBackgroundTaskScheduleProcessPendingMessagesCB()

void ml::BackgroundTaskManager::setBackgroundTaskScheduleProcessPendingMessagesCB	(	BackgroundTaskScheduleProcessPendingMessagesCB *	cb,
		void *	userData )

Sets the callback that will be called from any worker thread when a call of processPendingMessages() on the GUI thread is required.

It needs to be thread-safe and should cause a call to processPendingMessages() in the GUI thread, ideally from within an idle timer to avoid blocking the GUI. If this callback is not installed, the BackgroundTaskManager will only run synchronous tasks. It should be set up in the early initialization phase of an application. Note: you must not change this while an asynchronous background task is running!

◆ supportsAsynchronousTasks()

bool ml::BackgroundTaskManager::supportsAsynchronousTasks ( )

Returns whether asynchronous tasks are supported, which is the case if setBackgroundTaskScheduleProcessPendingMessagesCB was called with a non-NULL callback.

◆ totalTaskCount()

int ml::BackgroundTaskManager::totalTaskCount ( )

Returns the number of queued and running tasks.

This is only valid in the GUI thread.

◆ waitForTask()

BackgroundTask * ml::BackgroundTaskManager::waitForTask ( )

protected

Waits for a new task and returns the new task from the queue.

Friends And Related Symbol Documentation

◆ BackgroundTask

friend class BackgroundTask

friend

Definition at line 162 of file mlBackgroundTaskManager.h.

◆ BackgroundTaskFinishedMessage

friend class BackgroundTaskFinishedMessage

friend

Definition at line 161 of file mlBackgroundTaskManager.h.

◆ BackgroundTaskManagerPrivate

friend class BackgroundTaskManagerPrivate

friend

Definition at line 199 of file mlBackgroundTaskManager.h.

◆ BackgroundTaskManagerWorkerFunc

friend struct BackgroundTaskManagerWorkerFunc

friend

Definition at line 160 of file mlBackgroundTaskManager.h.

The documentation for this class was generated from the following file:

MeVis/Foundation/Sources/MLBackgroundTasks/mlBackgroundTaskManager.h

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Friends

Detailed Description

Member Function Documentation

◆ addObserver()

◆ cancelPendingRequestsForTask()

◆ cleanup()

◆ ensureGUIThread()

◆ ensureWorkerThread()

◆ getBackgroundTaskScheduleProcessPendingMessagesCB()

◆ getPageRequestProcessor()

◆ getStatusInformation()

◆ getUniqueTaskId()

◆ hasSynchronousTask()

◆ init()

◆ processPendingMessages()

◆ removeMessagesForReceiver()

◆ removeObserver()

◆ removeTaskFromQueueAndSendTaskFinished()

◆ runTask()

◆ self()

◆ sendMessageToGUI()

◆ sendMessageToTask()

◆ sendTaskAdded()

◆ sendTaskFinishedMessage()

◆ sendTaskRemoved()

◆ sendTaskStatusUpdated()

◆ setBackgroundTaskScheduleProcessPendingMessagesCB()

◆ supportsAsynchronousTasks()

◆ totalTaskCount()

◆ waitForTask()

Friends And Related Symbol Documentation

◆ BackgroundTask

◆ BackgroundTaskFinishedMessage

◆ BackgroundTaskManagerPrivate

◆ BackgroundTaskManagerWorkerFunc