org.jtrim2.executor

Interface UpdateTaskExecutor

All Known Implementing Classes:

GenericUpdateTaskExecutor

public interface UpdateTaskExecutor

An interface for executing tasks when only the last task is important. Implementations of this interface are therefore allowed to silently discard tasks that where scheduled to them previously. That is if scheduling task1 happen-before scheduling task2, task1 may be silently discarded and never executed.

For example see the following code:

 void testExecute() {
   UpdateTaskExecutor executor = ...;
   executor.execute(() -> System.out.print("1"));
   executor.execute(() -> System.out.print("2"));
   executor.execute(() -> System.out.print("3"));
 }
 

The method testExecute may either print "3" or "23" or "123", depending on the implementation and other external conditions.

The UpdateTaskExecutor is particularly good when reporting progress to be displayed. Since in this case previously reported progresses would have been overwritten anyway, so it is safe to discard old tasks.

Note that although not strictly required to execute tasks in the order they were scheduled but in most cases an UpdateTaskExecutor works well only when executes task in order.

Thread safety

Implementations of this interface are required to be safe to use by multiple threads concurrently.

Synchronization transparency

The methods of this interface are not required to be synchronization transparent.

See Also:

GenericUpdateTaskExecutor

Method Summary

Modifier and Type	Method and Description
void	execute(Runnable task) Submits a task which is to be executed in the future.

Method Detail

execute

void execute(Runnable task)

Submits a task which is to be executed in the future. This task may cause previously submitted tasks to be discarded an never run. Therefore the currently submitted task may get discarded by a subsequent execute call.

Parameters:

task - the task to be executed. This argument cannot be null.