Package com.biomatters.geneious.publicapi.utilities

Class MultiThreadedTask<ResultType>

java.lang.Object

com.biomatters.geneious.publicapi.utilities.MultiThreadedTask<ResultType>

public abstract class MultiThreadedTask<ResultType>
extends java.lang.Object

Manages a task that can be split over multiple threads.

Example 1: to split a task across multiple threads (1 per processor), use:

     List<ResultFromSingleThread> results = new MultiThreadedTask<ResultFromSingleThread>() {

Since:

API 4.610 (Geneious 6.1.0)

See Also:

MultiThreadedProcessingSystem

Constructor Summary

Constructors

Constructor	Description
MultiThreadedTask()	Creates a task split over a number of threads equal to the number of processors available on this machine.
MultiThreadedTask(int numberOfThreads)	Creates a task split over the specified number of threads

Method Summary

Modifier and Type	Method	Description
static int	getNumberOfProcessors()
static int	getNumberOfProcessorsSlightlyReducedIfLotsOfProcessors()
boolean	hasAnyPartThrownAnException()
java.util.List<ResultType>	run()	Creates threads, executes all the parts and waits for them to finish before returning.
abstract ResultType	run(int partNumber, int numberOfParts)	Runs a part of this task in a single thread.

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiThreadedTask

public MultiThreadedTask()

Creates a task split over a number of threads equal to the number of processors available on this machine.

MultiThreadedTask

public MultiThreadedTask(int numberOfThreads)

Creates a task split over the specified number of threads

Parameters:

numberOfThreads - the number of threads

Method Detail

getNumberOfProcessors

public static int getNumberOfProcessors()

Returns:

the number of processors on this machine. You should probably use getNumberOfProcessorsSlightlyReducedIfLotsOfProcessors() instead if the task may allocate temporary memory.

getNumberOfProcessorsSlightlyReducedIfLotsOfProcessors

public static int getNumberOfProcessorsSlightlyReducedIfLotsOfProcessors()

Returns:

the number of processors on this machine. Equivalent to Runtime.getRuntime().availableProcessors() unless there are at least 16 processors, in which case this value may be reduced by 1 or 2 to give the JVM garbage collector a chance to run

Since:

API 4.1011 (Geneious 10.1.1)

run

public abstract ResultType run(int partNumber,
                               int numberOfParts)

Runs a part of this task in a single thread.

Parameters:

partNumber - the part number of this part of the task between 0 and numberOfParts-1 inclusive.

numberOfParts - the total number of parts this task has been split into.

Returns:

The results of this part.

run

public java.util.List<ResultType> run()

Creates threads, executes all the parts and waits for them to finish before returning. If at least one thread throws an exception, only the first exception caught by the thread manager in this method will will be thrown by this method.

Returns:

the results of all parts ordered by the partNumbers.

hasAnyPartThrownAnException

public boolean hasAnyPartThrownAnException()

Returns:

true if any of the threads/parts running this task have thrown an exception which has been caught by the thread manager in run(). It is recommended that each thread should periodically call this and terminate if this returns true. This is useful to ensure the task promptly fails when any part of the task crashes rather than delaying the crash propagation until all parts have finished. If the calling thread chooses to throw an exception when this returns true, that exception will not be propagated back to run() because only the first exception caught by the thread manager in run() will be thrown from run()

Since:

API 4.202230 (Geneious 2022.3.0)