com.hazelcast.util.executor

Class LoggingScheduledExecutor

java.lang.Object

java.util.concurrent.AbstractExecutorService

java.util.concurrent.ThreadPoolExecutor

java.util.concurrent.ScheduledThreadPoolExecutor

com.hazelcast.util.executor.LoggingScheduledExecutor

All Implemented Interfaces:

Executor, ExecutorService, ScheduledExecutorService

public class LoggingScheduledExecutor
extends ScheduledThreadPoolExecutor

Logs execution exceptions by overriding ThreadPoolExecutor.afterExecute(java.lang.Runnable, java.lang.Throwable) and ScheduledThreadPoolExecutor.decorateTask(java.lang.Runnable, java.util.concurrent.RunnableScheduledFuture<V>) methods. Reasoning is given tasks to ScheduledThreadPoolExecutor stops silently if there is an execution exception. Note: Task decoration is only needed to call given tasks toString methods. ScheduledExecutorService.scheduleWithFixedDelay(java.lang.Runnable, long, long, java.util.concurrent.TimeUnit) Remove on cancel: To prevent running into an accumulation of cancelled task which can cause gc related problems (e.g. transactions in combination with LockResource eviction), it is best that tasks are removed from the scheduler on cancellation. In Java 7+ the there is a method ScheduledThreadPoolExecutor#setRemoveOnCancelPolicy(boolean) which removes the runnable on cancellation. Removal of tasks is done in logarithmic time (see ScheduledThreadPoolExecutor.DelayedWorkQueue.indexOf where there is a direct lookup instead of a linear scan over the queue). So in Java 7 we try to set this method using reflection. In Java 7+ the manualRemoveOnCancel is ignored, since it has an efficient removal of cancelled tasks and therefore it will always apply it. If we would wrap the task with the RemoveOnCancelFuture, it would even prevent constant time removal. In Java 6 there is no such method setRemoveOnCancelPolicy and therefore the task is wrapped in a RemoveOnCancelFuture which will remove itself from the work-queue on cancellation. However this removal isn't done in constant time, but in linear time because Java 6 ScheduledThreadPoolExecutor doesn't support a constant time removal. By default in Java 6, the removal of this task is done based on the 'removeOnCancel' property which gets its value from the GroupProperty.TASK_SCHEDULER_REMOVE_ON_CANCEL

Nested Class Summary

Nested classes/interfaces inherited from class java.util.concurrent.ThreadPoolExecutor

ThreadPoolExecutor.AbortPolicy, ThreadPoolExecutor.CallerRunsPolicy, ThreadPoolExecutor.DiscardOldestPolicy, ThreadPoolExecutor.DiscardPolicy

Constructor Summary

Constructors

Constructor and Description
LoggingScheduledExecutor(ILogger logger, int corePoolSize, ThreadFactory threadFactory)
LoggingScheduledExecutor(ILogger logger, int corePoolSize, ThreadFactory threadFactory, boolean removeOnCancel)
LoggingScheduledExecutor(ILogger logger, int corePoolSize, ThreadFactory threadFactory, boolean removeOnCancel, RejectedExecutionHandler handler)
LoggingScheduledExecutor(ILogger logger, int corePoolSize, ThreadFactory threadFactory, RejectedExecutionHandler handler)

Method Summary

Modifier and Type	Method and Description
protected void	afterExecute(Runnable runnable, Throwable throwable)
protected <V> RunnableScheduledFuture<V>	decorateTask(Callable<V> callable, RunnableScheduledFuture<V> task)
protected <V> RunnableScheduledFuture<V>	decorateTask(Runnable runnable, RunnableScheduledFuture<V> task)
void	notifyShutdownInitiated()

Methods inherited from class java.util.concurrent.ScheduledThreadPoolExecutor

execute, getContinueExistingPeriodicTasksAfterShutdownPolicy, getExecuteExistingDelayedTasksAfterShutdownPolicy, getQueue, getRemoveOnCancelPolicy, schedule, schedule, scheduleAtFixedRate, scheduleWithFixedDelay, setContinueExistingPeriodicTasksAfterShutdownPolicy, setExecuteExistingDelayedTasksAfterShutdownPolicy, setRemoveOnCancelPolicy, shutdown, shutdownNow, submit, submit, submit

Methods inherited from class java.util.concurrent.ThreadPoolExecutor

allowCoreThreadTimeOut, allowsCoreThreadTimeOut, awaitTermination, beforeExecute, finalize, getActiveCount, getCompletedTaskCount, getCorePoolSize, getKeepAliveTime, getLargestPoolSize, getMaximumPoolSize, getPoolSize, getRejectedExecutionHandler, getTaskCount, getThreadFactory, isShutdown, isTerminated, isTerminating, prestartAllCoreThreads, prestartCoreThread, purge, remove, setCorePoolSize, setKeepAliveTime, setMaximumPoolSize, setRejectedExecutionHandler, setThreadFactory, terminated, toString

Methods inherited from class java.util.concurrent.AbstractExecutorService

invokeAll, invokeAll, invokeAny, invokeAny, newTaskFor, newTaskFor

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.concurrent.ExecutorService

awaitTermination, invokeAll, invokeAll, invokeAny, invokeAny, isShutdown, isTerminated

Constructor Detail

LoggingScheduledExecutor

public LoggingScheduledExecutor(ILogger logger,
                                int corePoolSize,
                                ThreadFactory threadFactory)

LoggingScheduledExecutor

public LoggingScheduledExecutor(ILogger logger,
                                int corePoolSize,
                                ThreadFactory threadFactory,
                                boolean removeOnCancel)

LoggingScheduledExecutor

public LoggingScheduledExecutor(ILogger logger,
                                int corePoolSize,
                                ThreadFactory threadFactory,
                                RejectedExecutionHandler handler)

LoggingScheduledExecutor

public LoggingScheduledExecutor(ILogger logger,
                                int corePoolSize,
                                ThreadFactory threadFactory,
                                boolean removeOnCancel,
                                RejectedExecutionHandler handler)

Method Detail

decorateTask

protected <V> RunnableScheduledFuture<V> decorateTask(Runnable runnable,
                                                      RunnableScheduledFuture<V> task)

Overrides:

decorateTask in class ScheduledThreadPoolExecutor

decorateTask

protected <V> RunnableScheduledFuture<V> decorateTask(Callable<V> callable,
                                                      RunnableScheduledFuture<V> task)

Overrides:

decorateTask in class ScheduledThreadPoolExecutor

afterExecute

protected void afterExecute(Runnable runnable,
                            Throwable throwable)

Overrides:

afterExecute in class ThreadPoolExecutor

notifyShutdownInitiated

public void notifyShutdownInitiated()