src/share/classes/java/util/concurrent/Future.java
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*** 45,91 ****
* <tt>cancel</tt> method. Additional methods are provided to
* determine if the task completed normally or was cancelled. Once a
* computation has completed, the computation cannot be cancelled.
* If you would like to use a <tt>Future</tt> for the sake
* of cancellability but not provide a usable result, you can
! * declare types of the form <tt>Future<?></tt> and
* return <tt>null</tt> as a result of the underlying task.
*
* <p>
* <b>Sample Usage</b> (Note that the following classes are all
* made-up.) <p>
! * <pre>
* interface ArchiveSearcher { String search(String target); }
* class App {
* ExecutorService executor = ...
* ArchiveSearcher searcher = ...
* void showSearch(final String target)
* throws InterruptedException {
! * Future<String> future
! * = executor.submit(new Callable<String>() {
* public String call() {
* return searcher.search(target);
* }});
* displayOtherThings(); // do other things while searching
* try {
* displayText(future.get()); // use future
* } catch (ExecutionException ex) { cleanup(); return; }
* }
! * }
! * </pre>
*
* The {@link FutureTask} class is an implementation of <tt>Future</tt> that
* implements <tt>Runnable</tt>, and so may be executed by an <tt>Executor</tt>.
* For example, the above construction with <tt>submit</tt> could be replaced by:
! * <pre>
! * FutureTask<String> future =
! * new FutureTask<String>(new Callable<String>() {
* public String call() {
* return searcher.search(target);
* }});
! * executor.execute(future);
! * </pre>
*
* <p>Memory consistency effects: Actions taken by the asynchronous computation
* <a href="package-summary.html#MemoryVisibility"> <i>happen-before</i></a>
* actions following the corresponding {@code Future.get()} in another thread.
*
--- 45,89 ----
* <tt>cancel</tt> method. Additional methods are provided to
* determine if the task completed normally or was cancelled. Once a
* computation has completed, the computation cannot be cancelled.
* If you would like to use a <tt>Future</tt> for the sake
* of cancellability but not provide a usable result, you can
! * declare types of the form {@code Future<?>} and
* return <tt>null</tt> as a result of the underlying task.
*
* <p>
* <b>Sample Usage</b> (Note that the following classes are all
* made-up.) <p>
! * <pre> {@code
* interface ArchiveSearcher { String search(String target); }
* class App {
* ExecutorService executor = ...
* ArchiveSearcher searcher = ...
* void showSearch(final String target)
* throws InterruptedException {
! * Future<String> future
! * = executor.submit(new Callable<String>() {
* public String call() {
* return searcher.search(target);
* }});
* displayOtherThings(); // do other things while searching
* try {
* displayText(future.get()); // use future
* } catch (ExecutionException ex) { cleanup(); return; }
* }
! * }}</pre>
*
* The {@link FutureTask} class is an implementation of <tt>Future</tt> that
* implements <tt>Runnable</tt>, and so may be executed by an <tt>Executor</tt>.
* For example, the above construction with <tt>submit</tt> could be replaced by:
! * <pre> {@code
! * FutureTask<String> future =
! * new FutureTask<String>(new Callable<String>() {
* public String call() {
* return searcher.search(target);
* }});
! * executor.execute(future);}</pre>
*
* <p>Memory consistency effects: Actions taken by the asynchronous computation
* <a href="package-summary.html#MemoryVisibility"> <i>happen-before</i></a>
* actions following the corresponding {@code Future.get()} in another thread.
*