com.coreoz.wisp

Class Scheduler

java.lang.Object

com.coreoz.wisp.Scheduler

public final class Scheduler
extends Object

A Scheduler instance reference a group of jobs and is responsible to schedule these jobs at the expected time.

A job is executed only once at a time. The scheduler will never execute the same job twice at a time.

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_MINIMUM_DELAY_IN_MILLIS_TO_REPLACE_JOB Deprecated. This value is not used anymore It will be deleted in version 3.0.0.
static int	DEFAULT_THREAD_POOL_SIZE Deprecated. Default values are available in SchedulerConfig It will be deleted in version 3.0.0.

Constructor Summary

Constructors

Constructor and Description
Scheduler() Create a scheduler with the defaults defined at SchedulerConfig
Scheduler(int maxThreads) Create a scheduler with the defaults defined at SchedulerConfig and with a max number of worker threads
Scheduler(int maxThreads, long minimumDelayInMillisToReplaceJob) Deprecated. Use Scheduler(SchedulerConfig) to specify multiple configuration values. It will be deleted in version 3.0.0.
Scheduler(int maxThreads, long minimumDelayInMillisToReplaceJob, TimeProvider timeProvider) Deprecated. Use Scheduler(SchedulerConfig) to specify multiple configuration values. It will be deleted in version 3.0.0.
Scheduler(SchedulerConfig config) Create a scheduler according to the configuration

Method Summary

Modifier and Type	Method and Description
CompletionStage<Job>	cancel(String jobName) Issue a cancellation order for a job and returns immediately a promise that enables to follow the job cancellation status If the job is running, the scheduler will wait until it is finished to remove it from the jobs pool.
Optional<Job>	findJob(String name) Find a job by its name
void	gracefullyShutdown() Wait until the current running jobs are executed and cancel jobs that are planned to be executed.
void	gracefullyShutdown(Duration timeout) Wait until the current running jobs are executed and cancel jobs that are planned to be executed.
Collection<Job>	jobStatus() Fetch the status of all the jobs that has been registered on the Scheduler including the JobStatus.DONE jobs
void	remove(String jobName) Remove a terminated job, so with the status JobStatus.DONE), from the monitored jobs.
Job	schedule(Runnable runnable, Schedule when) Schedule the executions of a process.
Job	schedule(String nullableName, Runnable runnable, Schedule when) Schedule the executions of a process.
SchedulerStats	stats() Fetch statistics about the current Scheduler

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_THREAD_POOL_SIZE

@Deprecated
public static final int DEFAULT_THREAD_POOL_SIZE

Deprecated. Default values are available in SchedulerConfig It will be deleted in version 3.0.0.

See Also:

Constant Field Values

DEFAULT_MINIMUM_DELAY_IN_MILLIS_TO_REPLACE_JOB

@Deprecated
public static final long DEFAULT_MINIMUM_DELAY_IN_MILLIS_TO_REPLACE_JOB

Deprecated. This value is not used anymore It will be deleted in version 3.0.0.

See Also:

Constant Field Values

Constructor Detail

Scheduler

public Scheduler()

Create a scheduler with the defaults defined at SchedulerConfig

Scheduler

public Scheduler(int maxThreads)

Create a scheduler with the defaults defined at SchedulerConfig and with a max number of worker threads

Parameters:

maxThreads - The maximum number of worker threads that can be created for the scheduler.

Throws:

IllegalArgumentException - if maxThreads <= 0

Scheduler

public Scheduler(SchedulerConfig config)

Create a scheduler according to the configuration

Throws:

IllegalArgumentException - if one of the following holds:
SchedulerConfig#getMinThreads() < 0
SchedulerConfig#getThreadsKeepAliveTime() < 0
SchedulerConfig#getMaxThreads() <= 0
SchedulerConfig#getMaxThreads() < SchedulerConfig#getMinThreads()

NullPointerException - if SchedulerConfig#getTimeProvider() is null

Scheduler

@Deprecated
public Scheduler(int maxThreads,
                              long minimumDelayInMillisToReplaceJob)

Deprecated. Use Scheduler(SchedulerConfig) to specify multiple configuration values. It will be deleted in version 3.0.0.

Throws:

IllegalArgumentException - if maxThreads <= 0

Scheduler

@Deprecated
public Scheduler(int maxThreads,
                              long minimumDelayInMillisToReplaceJob,
                              TimeProvider timeProvider)

Deprecated. Use Scheduler(SchedulerConfig) to specify multiple configuration values. It will be deleted in version 3.0.0.

Throws:

IllegalArgumentException - if maxThreads <= 0

NullPointerException - if timeProvider is null

Method Detail

schedule

public Job schedule(Runnable runnable,
                    Schedule when)

Schedule the executions of a process.

Parameters:

runnable - The process to be executed at a schedule

when - The Schedule at which the process will be executed

Returns:

The corresponding Job created.

Throws:

NullPointerException - if runnable or when are null

IllegalArgumentException - if the same instance of runnable is scheduled twice whereas the corresponding job status is not JobStatus.DONE

schedule

public Job schedule(String nullableName,
                    Runnable runnable,
                    Schedule when)

Schedule the executions of a process.

If a job already exists with the same name and has the status JobStatus.DONE, then the created job will inherit the stats of the existing done job: Job.executionsCount() and Job.lastExecutionTimeInMillis()

Parameters:

nullableName - The name of the created job

runnable - The process to be executed at a schedule

when - The Schedule at which the process will be executed

Returns:

The corresponding Job created.

Throws:

NullPointerException - if runnable or when are null

IllegalArgumentException - if the same nullableName is scheduled twice whereas the corresponding job status is not JobStatus.DONE

jobStatus

public Collection<Job> jobStatus()

Fetch the status of all the jobs that has been registered on the Scheduler including the JobStatus.DONE jobs

findJob

public Optional<Job> findJob(String name)

Find a job by its name

cancel

public CompletionStage<Job> cancel(String jobName)

Issue a cancellation order for a job and returns immediately a promise that enables to follow the job cancellation status

If the job is running, the scheduler will wait until it is finished to remove it from the jobs pool. If the job is not running, the job will just be removed from the pool.
After the job is cancelled, the job has the status JobStatus.DONE.

Parameters:

jobName - The job name to cancel

Returns:

The promise that succeed when the job is correctly cancelled and will not be executed again. If the job is running when cancel(String) is called, the promise will succeed when the job has finished executing.

Throws:

IllegalArgumentException - if there is no job corresponding to the job name.

remove

public void remove(String jobName)

Remove a terminated job, so with the status JobStatus.DONE), from the monitored jobs. The monitored jobs are the ones still referenced using jobStatus(). This can be useful to avoid memory leak in case many jobs with a short lifespan are created.

Parameters:

jobName - The job name to remove

Throws:

IllegalArgumentException - If there is no job corresponding to the job name or if the job is not on the status JobStatus.DONE)

gracefullyShutdown

public void gracefullyShutdown()

Wait until the current running jobs are executed and cancel jobs that are planned to be executed. There is a 10 seconds timeout

Throws:

InterruptedException - if the shutdown lasts more than 10 seconds

gracefullyShutdown

public void gracefullyShutdown(Duration timeout)

Wait until the current running jobs are executed and cancel jobs that are planned to be executed.

Parameters:

timeout - The maximum time to wait

Throws:

InterruptedException - if the shutdown lasts more than 10 seconds

stats

public SchedulerStats stats()

Fetch statistics about the current Scheduler