Task

Object Hierarchy:

Description:

[ CCode ( type_id = "gst_task_get_type ()" ) ]
public class Task : Object

Task is used by Element and Pad to provide the data passing threads in a Pipeline.

A Pad will typically start a Task to push or pull data to/from the peer pads. Most source elements start a Task to push data. In some cases a demuxer element can start a Task to pull data from a peer element. This is typically done when the demuxer can perform random access on the upstream peer element for improved performance.

Although convenience functions exist on Pad to start/pause/stop tasks, it might sometimes be needed to create a Task manually if it is not related to a Pad.

Before the Task can be run, it needs a RecMutex that can be set with set_lock.

The task can be started, paused and stopped with start, pause and stop respectively or with the set_state function.

A Task will repeatedly call the TaskFunction with the user data that was provided when creating the task with Task. While calling the function it will acquire the provided lock. The provided lock is released when the task pauses or stops.

Stopping a task with stop will not immediately make sure the task is not running anymore. Use join to make sure the task is completely stopped and the thread is stopped.

After creating a Task, use unref to free its resources. This can only be done when the task is not running anymore.

Task functions can send a Message to send out-of-band data to the application. The application can receive messages from the Bus in its mainloop.

For debugging purposes, the task will configure its object name as the thread name on Linux. Please note that the object name should be configured before the task is started; changing the object name after the task has been started, has no effect on the thread name.

Namespace: Gst

Package: gstreamer-1.0

Content:

Static methods:

public static void cleanup_all ()
Wait for all tasks to be stopped.

Creation methods:

public Task (owned TaskFunction func)
Create a new Task that will repeatedly call the provided func with user_data as a parameter.

Methods:

public TaskPool get_pool ()
Get the TaskPool that this task will use for its streaming threads.
public TaskState get_state ()
Get the current state of the task.
public bool join ()
Joins this.
public bool pause ()
Pauses this.
public bool resume ()
Resume this in case it was paused.
public void set_enter_callback (owned TaskThreadFunc enter_func)
Call enter_func when the task function of this is entered.
public void set_leave_callback (owned TaskThreadFunc leave_func)
Call leave_func when the task function of this is left.
public void set_lock (RecMutex mutex)
Set the mutex used by the task.
public void set_pool (TaskPool pool)
Set pool as the new GstTaskPool for this.
public bool set_state (TaskState state)
Sets the state of this to state.
public bool start ()
Starts this.
public bool stop ()
Stops this.

Fields:

public RecMutex @lock
public Cond cond
public TaskFunction func
public bool running
public TaskState state

Inherited Members:

All known members inherited from class Gst.Object

All known members inherited from class GLib.Object