generic_task.InterruptableTask Class Reference

This class represents a task in a module that can be safely executed by checking preconditions and pausing other tasks that are being executed as well. More...

Inheritance diagram for generic_task.InterruptableTask:

Collaboration diagram for generic_task.InterruptableTask:

Public Member Functions
def	__init__ (self, name, runner, references, config, kwargs)
	Create an Interruptable task. More...
def	log (self)
	Returns a logger object.
def	onchangestate (self, e)
	Fysom callback for state transition. More...
def	checkStartPrerequisites (self)
	Check whether this task can be started by checking if all tasks to be paused are either stopped or can be paused. More...
def	checkExtraStartPrerequisites (self)
	If your task has extra prerequisites that are not covered by checking if a certain task can be paused, overwrite this function when sub-classing. More...
def	checkPausePrerequisites (self)
	Check if task is allowed to pause based on external state. More...
def	checkExtraPausePrerequisites (self)
	If yout task has prerequisites for pausing, overwrite this function when subclassing and put the check here. More...
def	canPause (self)
	Check if task can pause based on its own state only.
def	startTask (self)
	Implement the operation to start your task here.
def	runTaskStep (self)
	Implement one work step of your task here. More...
def	pauseTask (self)
	Implement the operations necessary to pause your task here.
def	resumeTask (self)
	Implement the operations necessary to resume your task from being paused here.
def	cleanupTask (self)
	If your task leaves behind any undesired state, take care to remove it in this function. More...

Public Attributes
	lock
	name
	interruptable
	success
	runner
	ref
	config
	result

Static Public Attributes
	sigDoStart = QtCore.Signal()
	sigStarted = QtCore.Signal()
	sigNextTaskStep = QtCore.Signal()
	sigDoPause = QtCore.Signal()
	sigPaused = QtCore.Signal()
	sigDoResume = QtCore.Signal()
	sigResumed = QtCore.Signal()
	sigDoFinish = QtCore.Signal()
	sigFinished = QtCore.Signal()
	sigStateChanged = QtCore.Signal(object)
dictionary	prePostTasks = {}
dictionary	pauseTasks = {}
list	requiredModules = []

Detailed Description

This class represents a task in a module that can be safely executed by checking preconditions and pausing other tasks that are being executed as well.

The task can also be paused, given that the preconditions for pausing are met.

State diagram for InterruptableTask:

stopped -> starting --------—> running ------—> finishing -* ^ | _______| ^_________ | |<------—* v | v | pausing -> paused -> resuming | | | | | ^ v v | |----------—<-----—|-------—<------—|-----—<----—

Each state has a transition state that allow for checks, synchronizatuion and for parts of the task to influence its own execution via signals. This also allows the TaskRunner to be informed about what the task is doing and ensuring that a task is executed in the correct thread.

Constructor & Destructor Documentation

__init__()

def generic_task.InterruptableTask.__init__	(		self,
			name,
			runner,
			references,
			config,
			kwargs
	)

Create an Interruptable task.

Parameters

str	name: unique task name
object	runner: reference to the TaskRunner managing this task
dict	references: a dictionary of all required modules
dict	config: configuration dictionary

Member Function Documentation

checkExtraPausePrerequisites()

def generic_task.InterruptableTask.checkExtraPausePrerequisites

(

self

)

If yout task has prerequisites for pausing, overwrite this function when subclassing and put the check here.

Returns

bool: return True if task can be paused right now, False otherwise

checkExtraStartPrerequisites()

def generic_task.InterruptableTask.checkExtraStartPrerequisites

(

self

)

If your task has extra prerequisites that are not covered by checking if a certain task can be paused, overwrite this function when sub-classing.

Returns

bool: return True if task can be started, False otherwise

checkPausePrerequisites()

def generic_task.InterruptableTask.checkPausePrerequisites

(

self

)

Check if task is allowed to pause based on external state.

checkStartPrerequisites()

def generic_task.InterruptableTask.checkStartPrerequisites

(

self

)

Check whether this task can be started by checking if all tasks to be paused are either stopped or can be paused.

Also check custom prerequisites.

Returns

bool: True if task can be stated, False otherwise

cleanupTask()

def generic_task.InterruptableTask.cleanupTask

(

self

)

If your task leaves behind any undesired state, take care to remove it in this function.

It is called after a task has finished.

onchangestate()

def generic_task.InterruptableTask.onchangestate	(		self,
			e
	)

Fysom callback for state transition.

Parameters

object

e: Fysom state transition description

runTaskStep()

def generic_task.InterruptableTask.runTaskStep

(

self

)

Implement one work step of your task here.

Returns

bool: True if the task should continue running, False if it should finish.

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

• logic/generic_task.py