org.apache.flink.runtime.jobgraph.tasks

Class AbstractInvokable

java.lang.Object

org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable

Direct Known Subclasses:

BatchTask, DataSinkTask, DataSourceTask, IterationSynchronizationSinkTask, StreamTask

public abstract class AbstractInvokable
extends Object

This is the abstract base class for every task that can be executed by a TaskManager. Concrete tasks like the vertices of batch jobs (see BatchTask inherit from this class.

The TaskManager invokes the invoke() method when executing a task. All operations of the task happen in this method (setting up input output stream readers and writers as well as the task's core operation).

Constructor Summary

Constructors

Constructor and Description
AbstractInvokable()

Method Summary

Modifier and Type	Method and Description
void	cancel() This method is called when a task is canceled either as a result of a user abort or an execution failure.
int	getCurrentNumberOfSubtasks() Returns the current number of subtasks the respective task is split into.
Environment	getEnvironment() Returns the environment of this task.
ExecutionConfig	getExecutionConfig() Returns the global ExecutionConfig, obtained from the job configuration.
int	getIndexInSubtaskGroup() Returns the index of this subtask in the subtask group.
Configuration	getJobConfiguration() Returns the job configuration object which was attached to the original JobGraph.
Configuration	getTaskConfiguration() Returns the task configuration object which was attached to the original JobVertex.
ClassLoader	getUserCodeClassLoader() Returns the user code class loader of this invokable.
abstract void	invoke() Starts the execution.
void	setEnvironment(Environment environment) Sets the environment of this task.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractInvokable

public AbstractInvokable()

Method Detail

invoke

public abstract void invoke()
                     throws Exception

Starts the execution.

Must be overwritten by the concrete task implementation. This method is called by the task manager when the actual execution of the task starts.

All resources should be cleaned up when the method returns. Make sure to guard the code with try-finally blocks where necessary.

Throws:

Exception - Tasks may forward their exceptions for the TaskManager to handle through failure/recovery.

setEnvironment

public final void setEnvironment(Environment environment)

Sets the environment of this task.

Parameters:

environment - the environment of this task

getEnvironment

public Environment getEnvironment()

Returns the environment of this task.

Returns:

The environment of this task.

getUserCodeClassLoader

public ClassLoader getUserCodeClassLoader()

Returns the user code class loader of this invokable.

Returns:

user code class loader of this invokable.

getCurrentNumberOfSubtasks

public int getCurrentNumberOfSubtasks()

Returns the current number of subtasks the respective task is split into.

Returns:

the current number of subtasks the respective task is split into

getIndexInSubtaskGroup

public int getIndexInSubtaskGroup()

Returns the index of this subtask in the subtask group.

Returns:

the index of this subtask in the subtask group

getTaskConfiguration

public Configuration getTaskConfiguration()

Returns the task configuration object which was attached to the original JobVertex.

Returns:

the task configuration object which was attached to the original JobVertex

getJobConfiguration

public Configuration getJobConfiguration()

Returns the job configuration object which was attached to the original JobGraph.

Returns:

the job configuration object which was attached to the original JobGraph

getExecutionConfig

public ExecutionConfig getExecutionConfig()

Returns the global ExecutionConfig, obtained from the job configuration.

cancel

public void cancel()
            throws Exception

This method is called when a task is canceled either as a result of a user abort or an execution failure. It can be overwritten to respond to shut down the user code properly.

Throws:

Exception - thrown if any exception occurs during the execution of the user code