com.pushtechnology.diffusion.api.threads

Class ThreadService

java.lang.Object

com.pushtechnology.diffusion.api.threads.ThreadService

public final class ThreadService
extends Object

Provides Thread Handling Capabilities.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ThreadService.AbortRejectionPolicy A ThreadPoolRejectionHandler that simply throws an Exception.
static class	ThreadService.CallerRunsRejectionPolicy A ThreadPoolRejectionHandler which attempts to run the task in the current thread.

Field Summary

Fields

Modifier and Type	Field and Description
static String	SCHEDULE_DAILY Constant which represents a daily schedule.
static String	SCHEDULE_EVERY_MINUTE Constant which represents a cron entry which will execute every minute.

Method Summary

Modifier and Type	Method and Description
static void	bootstrap(com.pushtechnology.diffusion.threads.ThreadPoolManager someThreadPoolManager, com.pushtechnology.diffusion.scheduling.Scheduler someScheduler)
static ThreadPool	createThreadPool(String name, int coreSize, int maxSize, int queueSize, int priority) Creates a new thread pool.
static ThreadPool	getBackgroundThreadPool() Returns the background thread pool.
static ThreadPool	getThreadPool(String poolName) Returns a named thread pool.
static List<ThreadPool>	getThreadPools() Returns the full list of currently defined thread pools.
static Thread	newThread(Runnable runnable, String name, int priority, boolean daemon) This is a convenience method for creating a new thread.
static ScheduledFuture<?>	schedule(RunnableTask runnable, long initialDelay, long period, TimeUnit unit, boolean isConstantRate) Schedules a task for periodic execution.
static ScheduledFuture<?>	schedule(RunnableTask runnable, long delay, TimeUnit unit) Schedule a task for execution after a given period of time.
static Schedule	schedule(ScheduledTask task) Schedules a ScheduledTask to run according to a frequency schedule defined by the task itself.
static Schedule	schedule(String name, String frequency, RunnableTask task) Schedules a task to be run according to a schedule specified by a 'cron' like frequency pattern.

Methods inherited from class java.lang.Object

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

Field Detail

SCHEDULE_DAILY

public static final String SCHEDULE_DAILY

Constant which represents a daily schedule.

See Also:

Constant Field Values

SCHEDULE_EVERY_MINUTE

public static final String SCHEDULE_EVERY_MINUTE

Constant which represents a cron entry which will execute every minute.

See Also:

Constant Field Values

Method Detail

bootstrap

public static void bootstrap(com.pushtechnology.diffusion.threads.ThreadPoolManager someThreadPoolManager,
                             com.pushtechnology.diffusion.scheduling.Scheduler someScheduler)

getThreadPool

public static ThreadPool getThreadPool(String poolName)

Returns a named thread pool.

Parameters:

poolName - the pool name

Returns:

the named thread pool or null if no pool exists with the specified name.

getThreadPools

public static List<ThreadPool> getThreadPools()

Returns the full list of currently defined thread pools. This will include system pools such as the inbound, outbound and background thread pools.

Returns:

full list of currently defined pools.

createThreadPool

public static ThreadPool createThreadPool(String name,
                                          int coreSize,
                                          int maxSize,
                                          int queueSize,
                                          int priority)
                                   throws APIException

Creates a new thread pool.

Parameters:

name - a name for the thread pool.

coreSize - the number of core threads that should be in the pool. As threads are required then new threads will be created until this number is reached even if there are already idle threads in the pool.

maxSize - the maximum number of threads that may be created in the pool. A value of 0 indicates that the pool should be effectively unbounded (i.e. a value of Integer.MAX_VALUE is assumed) in which case the task queue would never be used.

queueSize - the size of the task queue. Tasks are queued if there are no idle threads in the pool and the maximum pool size has been reached.

priority - since 5.8 the priority cannot be changed and this parameter is ignored

Returns:

a new thread pool instance

Throws:

APIException - if unable to create the thread pool.

newThread

public static Thread newThread(Runnable runnable,
                               String name,
                               int priority,
                               boolean daemon)

This is a convenience method for creating a new thread.

The thread created will have an uncaught exception handler which will log exceptions.

Parameters:

runnable - the runnable

name - the thread name

priority - since 5.8 the priority cannot be changed and this parameter is ignored

daemon - whether thread is to be a daemon (see Thread.setDaemon(boolean))

Returns:

new thread

getBackgroundThreadPool

public static ThreadPool getBackgroundThreadPool()
                                          throws APIException

Returns the background thread pool.

Returns:

the background thread pool.

Throws:

APIException - if unable to get the background thread pool.

schedule

public static Schedule schedule(ScheduledTask task)
                         throws APIException

Schedules a ScheduledTask to run according to a frequency schedule defined by the task itself.

Tasks are run using the Background thread pool.

Parameters:

task - the task to schedule.

Returns:

a Schedule object that may be used to cancel the schedule.

Throws:

APIException - if unable to schedule the task.

schedule

public static Schedule schedule(String name,
                                String frequency,
                                RunnableTask task)
                         throws APIException

Schedules a task to be run according to a schedule specified by a 'cron' like frequency pattern.

Tasks are run on the Background thread pool.

Parameters:

name - a name that will identify the scheduled task.

frequency - the frequency at which to run the task, specified as a 'cron' pattern, this is broken into five parts, separated by spaces:

1) Minutes sub-pattern.
During which minutes of the hour should the task been launched? The values range is from 0 to 59.

2) Hours sub-pattern.
During which hours of the day should the task been launched? The values range is from 0 to 23.

3) Days of month sub-pattern.
During which days of the month should the task been launched? The values range is from 1 to 31. The special value "L" can be used to recognise the last day of month.

4) Months sub-pattern.
During which months of the year should the task be launched? The values range is from 1 (January) to 12 (December), otherwise this sub-pattern allows the aliases "jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov" and "dec".

5) Days of week sub-pattern.
During which days of the week should the task been launched? The values range is from 0 (Sunday) to 6 (Saturday), otherwise this sub-pattern allows the aliases "sun", "mon", "tue", "wed", "thu", "fri" and "sat".

The '*' wildcard character is also admitted, indicating "every minute of the hour", "every hour of the day", "every day of the month", "every month of the year" and "every day of the week", according to the sub-pattern in which it is used.

task - the task to run

Returns:

a Schedule object that may be used to cancel the schedule.

Throws:

APIException - if unable to schedule the task

schedule

public static ScheduledFuture<?> schedule(RunnableTask runnable,
                                          long delay,
                                          TimeUnit unit)
                                   throws APIException

Schedule a task for execution after a given period of time.

The task is scheduled to run in the background thread pool.

Parameters:

runnable - the task to run.

delay - time before execution.

unit - time unit of the delay parameter.

Returns:

a Future representing pending completion of the task, and whose get() method will throw an exception upon cancellation.

Throws:

APIException - if unable to schedule the task.

schedule

public static ScheduledFuture<?> schedule(RunnableTask runnable,
                                          long initialDelay,
                                          long period,
                                          TimeUnit unit,
                                          boolean isConstantRate)
                                   throws APIException

Schedules a task for periodic execution.

The task is first executed after the given initial delay, and subsequently at the given periodic interval.

Executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, 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. As this is a background thread, this will be given a Thread.MIN_PRIORITY

Tasks are executed in the background thread pool.

Parameters:

runnable - the task to execute.

initialDelay - the time to delay first execution.

period - the period between successive executions.

unit - the time unit of the initialDelay and period parameters

isConstantRate - If true then the period specified is the period between successive initiations of the task. If false then the period is the delay between successive runs of the task i.e. it is the gap between the task finishing and it starting again

Returns:

a Future representing pending completion of the task, and whose get() method will throw an exception upon cancellation.

Throws:

APIException - if unable to schedule periodic task.