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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/external/jsr166/java/util/concurrent/ScheduledExecutorService.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/external/jsr166/java/util/concurrent/ScheduledExecutorService.java | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/external/jsr166/java/util/concurrent/ScheduledExecutorService.java b/gcc-4.4.3/libjava/classpath/external/jsr166/java/util/concurrent/ScheduledExecutorService.java new file mode 100644 index 000000000..976537ef5 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/external/jsr166/java/util/concurrent/ScheduledExecutorService.java @@ -0,0 +1,159 @@ +/* + * Written by Doug Lea with assistance from members of JCP JSR-166 + * Expert Group and released to the public domain, as explained at + * http://creativecommons.org/licenses/publicdomain + */ + +package java.util.concurrent; +import java.util.concurrent.atomic.*; +import java.util.*; + +/** + * An {@link ExecutorService} that can schedule commands to run after a given + * delay, or to execute periodically. + * + * <p> The <tt>schedule</tt> methods create tasks with various delays + * and return a task object that can be used to cancel or check + * execution. The <tt>scheduleAtFixedRate</tt> and + * <tt>scheduleWithFixedDelay</tt> methods create and execute tasks + * that run periodically until cancelled. + * + * <p> Commands submitted using the {@link Executor#execute} and + * {@link ExecutorService} <tt>submit</tt> methods are scheduled with + * a requested delay of zero. Zero and negative delays (but not + * periods) are also allowed in <tt>schedule</tt> methods, and are + * treated as requests for immediate execution. + * + * <p>All <tt>schedule</tt> methods accept <em>relative</em> delays and + * periods as arguments, not absolute times or dates. It is a simple + * matter to transform an absolute time represented as a {@link + * java.util.Date} to the required form. For example, to schedule at + * a certain future <tt>date</tt>, you can use: <tt>schedule(task, + * date.getTime() - System.currentTimeMillis(), + * TimeUnit.MILLISECONDS)</tt>. Beware however that expiration of a + * relative delay need not coincide with the current <tt>Date</tt> at + * which the task is enabled due to network time synchronization + * protocols, clock drift, or other factors. + * + * The {@link Executors} class provides convenient factory methods for + * the ScheduledExecutorService implementations provided in this package. + * + * <h3>Usage Example</h3> + * + * Here is a class with a method that sets up a ScheduledExecutorService + * to beep every ten seconds for an hour: + * + * <pre> + * import static java.util.concurrent.TimeUnit.*; + * class BeeperControl { + * private final ScheduledExecutorService scheduler = + * Executors.newScheduledThreadPool(1); + * + * public void beepForAnHour() { + * final Runnable beeper = new Runnable() { + * public void run() { System.out.println("beep"); } + * }; + * final ScheduledFuture<?> beeperHandle = + * scheduler.scheduleAtFixedRate(beeper, 10, 10, SECONDS); + * scheduler.schedule(new Runnable() { + * public void run() { beeperHandle.cancel(true); } + * }, 60 * 60, SECONDS); + * } + * } + * </pre> + * + * @since 1.5 + * @author Doug Lea + */ +public interface ScheduledExecutorService extends ExecutorService { + + /** + * Creates and executes a one-shot action that becomes enabled + * after the given delay. + * + * @param command the task to execute + * @param delay the time from now to delay execution + * @param unit the time unit of the delay parameter + * @return a ScheduledFuture representing pending completion of + * the task and whose <tt>get()</tt> method will return + * <tt>null</tt> upon completion + * @throws RejectedExecutionException if the task cannot be + * scheduled for execution + * @throws NullPointerException if command is null + */ + public ScheduledFuture<?> schedule(Runnable command, + long delay, TimeUnit unit); + + /** + * Creates and executes a ScheduledFuture that becomes enabled after the + * given delay. + * + * @param callable the function to execute + * @param delay the time from now to delay execution + * @param unit the time unit of the delay parameter + * @return a ScheduledFuture that can be used to extract result or cancel + * @throws RejectedExecutionException if the task cannot be + * scheduled for execution + * @throws NullPointerException if callable is null + */ + public <V> ScheduledFuture<V> schedule(Callable<V> callable, + long delay, TimeUnit unit); + + /** + * Creates and executes a periodic action that becomes enabled first + * after the given initial delay, and subsequently with the given + * period; that is executions will commence after + * <tt>initialDelay</tt> then <tt>initialDelay+period</tt>, then + * <tt>initialDelay + 2 * period</tt>, and so on. + * If any execution of the task + * encounters an exception, subsequent executions are suppressed. + * Otherwise, the task will only terminate via cancellation or + * termination of the executor. If any execution of this task + * takes longer than its period, then subsequent executions + * may start late, but will not concurrently execute. + * + * @param command the task to execute + * @param initialDelay the time to delay first execution + * @param period the period between successive executions + * @param unit the time unit of the initialDelay and period parameters + * @return a ScheduledFuture representing pending completion of + * the task, and whose <tt>get()</tt> method will throw an + * exception upon cancellation + * @throws RejectedExecutionException if the task cannot be + * scheduled for execution + * @throws NullPointerException if command is null + * @throws IllegalArgumentException if period less than or equal to zero + */ + public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, + long initialDelay, + long period, + TimeUnit unit); + + /** + * Creates and executes a periodic action that becomes enabled first + * after the given initial delay, and subsequently with the + * given delay between the termination of one execution and the + * commencement of the next. If any execution of the task + * encounters an exception, subsequent executions are suppressed. + * Otherwise, the task will only terminate via cancellation or + * termination of the executor. + * + * @param command the task to execute + * @param initialDelay the time to delay first execution + * @param delay the delay between the termination of one + * execution and the commencement of the next + * @param unit the time unit of the initialDelay and delay parameters + * @return a ScheduledFuture representing pending completion of + * the task, and whose <tt>get()</tt> method will throw an + * exception upon cancellation + * @throws RejectedExecutionException if the task cannot be + * scheduled for execution + * @throws NullPointerException if command is null + * @throws IllegalArgumentException if delay less than or equal to zero + */ + public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, + long initialDelay, + long delay, + TimeUnit unit); + +} |