org.bytedeco.arrow

Class TaskGroup

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.arrow.TaskGroup

All Implemented Interfaces:

AutoCloseable

@Namespace(value="arrow::internal")
 @Properties(inherit=arrow.class)
public class TaskGroup
extends Pointer

\brief A group of related tasks A TaskGroup executes tasks with the signature Status(). Execution can be serial or parallel, depending on the TaskGroup implementation. When Finish() returns, it is guaranteed that all tasks have finished, or at least one has errored. Once an error has occurred any tasks that are submitted to the task group will not run. The call to Append will simply return without scheduling the task. If the task group is parallel it is possible that multiple tasks could be running at the same time and one of those tasks fails. This will put the task group in a failure state (so additional tasks cannot be run) however it will not interrupt running tasks. Finish will not complete until all running tasks have finished, even if one task fails. Once a task group has finished new tasks may not be added to it. If you need to start a new batch of work then you should create a new task group.

Nested Class Summary

Nested classes/interfaces inherited from class org.bytedeco.javacpp.Pointer

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
TaskGroup(Pointer p) Pointer cast constructor.

Method Summary

Modifier and Type	Method and Description
Status	current_status() The current aggregate error Status.
Status	Finish() Wait for execution of all tasks (and subgroups) to be finished, or for at least one task (or subgroup) to error out.
Future	FinishAsync() Returns a future that will complete the first time all tasks are finished.
static TaskGroup	MakeSerial()
static TaskGroup	MakeSerial(StopToken arg0)
static TaskGroup	MakeThreaded(Executor arg0)
static TaskGroup	MakeThreaded(Executor arg0, StopToken arg1)
boolean	ok() Whether some tasks have already failed.
int	parallelism() How many tasks can typically be executed in parallel.

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, availablePhysicalBytes, calloc, capacity, capacity, close, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, formatBytes, free, getPointer, getPointer, getPointer, getPointer, hashCode, isNull, isNull, limit, limit, malloc, maxBytes, maxPhysicalBytes, memchr, memcmp, memcpy, memmove, memset, offsetAddress, offsetof, offsetof, parseBytes, physicalBytes, position, position, put, realloc, referenceCount, releaseReference, retainReference, setNull, sizeof, sizeof, toString, totalBytes, totalCount, totalPhysicalBytes, withDeallocator, zero

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

TaskGroup

public TaskGroup(Pointer p)

Pointer cast constructor. Invokes Pointer(Pointer).

Method Detail

Finish

@ByVal
public Status Finish()

Wait for execution of all tasks (and subgroups) to be finished, or for at least one task (or subgroup) to error out. The returned Status propagates the error status of the first failing task (or subgroup).

FinishAsync

@ByVal
public Future FinishAsync()

Returns a future that will complete the first time all tasks are finished. This should be called only after all top level tasks have been added to the task group. If you are using a TaskGroup asynchronously there are a few considerations to keep in mind. The tasks should not block on I/O, etc (defeats the purpose of using futures) and should not be doing any nested locking or you run the risk of the tasks getting stuck in the thread pool waiting for tasks which cannot get scheduled. Primarily this call is intended to help migrate existing work written with TaskGroup in mind to using futures without having to do a complete conversion on the first pass.

current_status

@ByVal
public Status current_status()

The current aggregate error Status. Non-blocking, useful for stopping early.

ok

@Cast(value="bool")
public boolean ok()

Whether some tasks have already failed. Non-blocking, useful for stopping early.

parallelism

public int parallelism()

How many tasks can typically be executed in parallel. This is only a hint, useful for testing or debugging.

MakeSerial

@SharedPtr
public static TaskGroup MakeSerial(@ByVal(nullValue="arrow::StopToken::Unstoppable()")
                                              StopToken arg0)

MakeSerial

@SharedPtr
public static TaskGroup MakeSerial()

MakeThreaded

@SharedPtr
public static TaskGroup MakeThreaded(Executor arg0,
                                                @ByVal(nullValue="arrow::StopToken::Unstoppable()")
                                                StopToken arg1)

MakeThreaded

@SharedPtr
public static TaskGroup MakeThreaded(Executor arg0)