org.apache.camel.spi

Interface ExecutorServiceManager

All Superinterfaces:

AutoCloseable, Service, ShutdownableService, StaticService

public interface ExecutorServiceManager
extends ShutdownableService, StaticService

Strategy to create thread pools.

This manager is pluggable so you can plugin a custom provider, for example if you want to leverage the WorkManager for a JEE server.

You may want to just implement a custom ThreadPoolFactory and rely on the org.apache.camel.impl.DefaultExecutorServiceManager, if that is sufficient. The ThreadPoolFactory is always used for creating the actual thread pools. You can implement a custom ThreadPoolFactory to leverage the WorkManager for a JEE server.

The ThreadPoolFactory has pure JDK API, where as this ExecutorServiceManager has Camel API concepts such as ThreadPoolProfile. Therefore it may be easier to only implement a custom ThreadPoolFactory.

This manager has fine grained methods for creating various thread pools, however custom strategies do not have to exactly create those kind of pools. Feel free to return a shared or different kind of pool.

If you use the newXXX methods to create thread pools, then Camel will by default take care of shutting down those created pools when CamelContext is shutting down.

For more information about shutting down thread pools see the shutdown(java.util.concurrent.ExecutorService) and shutdownNow(java.util.concurrent.ExecutorService), and getShutdownAwaitTermination() methods. Notice the details about using a graceful shutdown at first, and then falling back to aggressive shutdown in case of await termination timeout occurred.

See Also:

ThreadPoolFactory

Method Summary

Modifier and Type	Method and Description
boolean	awaitTermination(ExecutorService executorService, long shutdownAwaitTermination) Awaits the termination of the thread pool.
ThreadPoolProfile	getDefaultThreadPoolProfile() Gets the default thread pool profile
long	getShutdownAwaitTermination() Gets the time to wait for thread pools to shutdown orderly, when invoking the ShutdownableService.shutdown() method.
String	getThreadNamePattern() Gets the thread name pattern to use
ThreadPoolFactory	getThreadPoolFactory() Gets the ThreadPoolFactory to use for creating the thread pools.
ThreadPoolProfile	getThreadPoolProfile(String id) Gets the thread pool profile by the given id
ExecutorService	newCachedThreadPool(Object source, String name) Creates a new cached thread pool.
ScheduledExecutorService	newDefaultScheduledThreadPool(Object source, String name) Creates a new scheduled thread pool using the default thread pool profile.
ExecutorService	newDefaultThreadPool(Object source, String name) Creates a new thread pool using the default thread pool profile.
ExecutorService	newFixedThreadPool(Object source, String name, int poolSize) Creates a new fixed thread pool (the pool will not grow or shrink but has a fixed number of threads constantly).
ScheduledExecutorService	newScheduledThreadPool(Object source, String name, int poolSize) Creates a new scheduled thread pool.
ScheduledExecutorService	newScheduledThreadPool(Object source, String name, String profileId) Creates a new scheduled thread pool using a profile id
ScheduledExecutorService	newScheduledThreadPool(Object source, String name, ThreadPoolProfile profile) Creates a new scheduled thread pool using a profile
ExecutorService	newSingleThreadExecutor(Object source, String name) Creates a new single-threaded thread pool.
ScheduledExecutorService	newSingleThreadScheduledExecutor(Object source, String name) Creates a new single-threaded thread pool.
Thread	newThread(String name, Runnable runnable) Creates a new daemon thread with the given name.
ExecutorService	newThreadPool(Object source, String name, int poolSize, int maxPoolSize) Creates a new thread pool.
ExecutorService	newThreadPool(Object source, String name, String profileId) Creates a new thread pool using using the given profile id
ExecutorService	newThreadPool(Object source, String name, ThreadPoolProfile profile) Creates a new thread pool using the given profile
void	registerThreadPoolProfile(ThreadPoolProfile profile) Registers the given thread pool profile
String	resolveThreadName(String name) Creates a full thread name
void	setDefaultThreadPoolProfile(ThreadPoolProfile defaultThreadPoolProfile) Sets the default thread pool profile
void	setShutdownAwaitTermination(long timeInMillis) Sets the time to wait for thread pools to shutdown orderly, when invoking the ShutdownableService.shutdown() method.
void	setThreadNamePattern(String pattern) Sets the thread name pattern used for creating the full thread name.
void	setThreadPoolFactory(ThreadPoolFactory threadPoolFactory) Sets a custom ThreadPoolFactory to use
void	shutdown(ExecutorService executorService) Shutdown the given executor service (not graceful).
void	shutdownGraceful(ExecutorService executorService) Shutdown the given executor service graceful at first, and then aggressively if the await termination timeout was hit.
void	shutdownGraceful(ExecutorService executorService, long shutdownAwaitTermination) Shutdown the given executor service graceful at first, and then aggressively if the await termination timeout was hit.
List<Runnable>	shutdownNow(ExecutorService executorService) Shutdown now the given executor service aggressively.

Methods inherited from interface org.apache.camel.ShutdownableService

shutdown

Methods inherited from interface org.apache.camel.Service

build, close, init, start, stop

Method Detail

getThreadPoolFactory

ThreadPoolFactory getThreadPoolFactory()

Gets the ThreadPoolFactory to use for creating the thread pools.

Returns:

the thread pool factory

setThreadPoolFactory

void setThreadPoolFactory(ThreadPoolFactory threadPoolFactory)

Sets a custom ThreadPoolFactory to use

Parameters:

threadPoolFactory - the thread pool factory

resolveThreadName

String resolveThreadName(String name)

Creates a full thread name

Parameters:

name - name which is appended to the full thread name

Returns:

the full thread name

getThreadPoolProfile

ThreadPoolProfile getThreadPoolProfile(String id)

Gets the thread pool profile by the given id

Parameters:

id - id of the thread pool profile to get

Returns:

the found profile, or null if not found

registerThreadPoolProfile

void registerThreadPoolProfile(ThreadPoolProfile profile)

Registers the given thread pool profile

Parameters:

profile - the profile

setDefaultThreadPoolProfile

void setDefaultThreadPoolProfile(ThreadPoolProfile defaultThreadPoolProfile)

Sets the default thread pool profile

Parameters:

defaultThreadPoolProfile - the new default thread pool profile

getDefaultThreadPoolProfile

ThreadPoolProfile getDefaultThreadPoolProfile()

Gets the default thread pool profile

Returns:

the default profile which are newer null

setThreadNamePattern

void setThreadNamePattern(String pattern)
                   throws IllegalArgumentException

Sets the thread name pattern used for creating the full thread name.

The default pattern is: Camel (#camelId#) thread ##counter# - #name#

Where #camelId# is the name of the CamelContext
and #counter# is a unique incrementing counter.
and #name# is the regular thread name.
You can also use #longName# is the long thread name which can include endpoint parameters etc.

Parameters:

pattern - the pattern

Throws:

IllegalArgumentException - if the pattern is invalid.

getThreadNamePattern

String getThreadNamePattern()

Gets the thread name pattern to use

Returns:

the pattern

setShutdownAwaitTermination

void setShutdownAwaitTermination(long timeInMillis)

Sets the time to wait for thread pools to shutdown orderly, when invoking the ShutdownableService.shutdown() method.

The default value is 10000 millis.

Parameters:

timeInMillis - time in millis.

getShutdownAwaitTermination

long getShutdownAwaitTermination()

Gets the time to wait for thread pools to shutdown orderly, when invoking the ShutdownableService.shutdown() method.

The default value is 10000 millis.

Returns:

the timeout value

newThread

Thread newThread(String name,
                 Runnable runnable)

Creates a new daemon thread with the given name.

Parameters:

name - name which is appended to the thread name

runnable - a runnable to be executed by new thread instance

Returns:

the created thread

newDefaultThreadPool

ExecutorService newDefaultThreadPool(Object source,
                                     String name)

Creates a new thread pool using the default thread pool profile.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

Returns:

the created thread pool

newDefaultScheduledThreadPool

ScheduledExecutorService newDefaultScheduledThreadPool(Object source,
                                                       String name)

Creates a new scheduled thread pool using the default thread pool profile.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

Returns:

the created thread pool

newThreadPool

ExecutorService newThreadPool(Object source,
                              String name,
                              ThreadPoolProfile profile)

Creates a new thread pool using the given profile

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

profile - the profile with the thread pool settings to use

Returns:

the created thread pool

newThreadPool

ExecutorService newThreadPool(Object source,
                              String name,
                              String profileId)

Creates a new thread pool using using the given profile id

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

profileId - the id of the profile with the thread pool settings to use

Returns:

the created thread pool, or null if the thread pool profile could not be found

newThreadPool

ExecutorService newThreadPool(Object source,
                              String name,
                              int poolSize,
                              int maxPoolSize)

Creates a new thread pool.

Will fallback and use values from the default thread pool profile for keep alive time, rejection policy and other parameters which cannot be specified.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

poolSize - the core pool size

maxPoolSize - the maximum pool size

Returns:

the created thread pool

newSingleThreadExecutor

ExecutorService newSingleThreadExecutor(Object source,
                                        String name)

Creates a new single-threaded thread pool. This is often used for background threads.

Notice that there will always be a single thread in the pool. If you want the pool to be able to shrink to no threads, then use the newThreadPool method, and use 0 in core pool size, and 1 in max pool size.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

Returns:

the created thread pool

newCachedThreadPool

ExecutorService newCachedThreadPool(Object source,
                                    String name)

Creates a new cached thread pool.

Important: Using cached thread pool should be used by care as they have no upper bound on created threads, and have no task backlog, and can therefore overload the JVM.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

Returns:

the created thread pool

newFixedThreadPool

ExecutorService newFixedThreadPool(Object source,
                                   String name,
                                   int poolSize)

Creates a new fixed thread pool (the pool will not grow or shrink but has a fixed number of threads constantly).

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

poolSize - the core pool size

Returns:

the created thread pool

newScheduledThreadPool

ScheduledExecutorService newScheduledThreadPool(Object source,
                                                String name,
                                                int poolSize)

Creates a new scheduled thread pool.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

poolSize - the core pool size

Returns:

the created thread pool

newSingleThreadScheduledExecutor

ScheduledExecutorService newSingleThreadScheduledExecutor(Object source,
                                                          String name)

Creates a new single-threaded thread pool. This is often used for background threads.

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

Returns:

the created thread pool

newScheduledThreadPool

ScheduledExecutorService newScheduledThreadPool(Object source,
                                                String name,
                                                ThreadPoolProfile profile)

Creates a new scheduled thread pool using a profile

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

profile - the profile with the thread pool settings to use

Returns:

created thread pool

newScheduledThreadPool

ScheduledExecutorService newScheduledThreadPool(Object source,
                                                String name,
                                                String profileId)

Creates a new scheduled thread pool using a profile id

Parameters:

source - the source object, usually it should be this passed in as parameter

name - name which is appended to the thread name

profileId - the id of the profile with the thread pool settings to use

Returns:

created thread pool

shutdown

void shutdown(ExecutorService executorService)

Shutdown the given executor service (not graceful).

This implementation will issues a regular shutdown of the executor service, ie calling ExecutorService.shutdown() and return.

Parameters:

executorService - the executor service to shutdown

See Also:

ExecutorService.shutdown()

shutdownGraceful

void shutdownGraceful(ExecutorService executorService)

Shutdown the given executor service graceful at first, and then aggressively if the await termination timeout was hit.

Will try to perform an orderly shutdown by giving the running threads time to complete tasks, before going more aggressively by doing a shutdownNow(java.util.concurrent.ExecutorService) which forces a shutdown. The getShutdownAwaitTermination() is used as timeout value waiting for orderly shutdown to complete normally, before going aggressively.

Parameters:

executorService - the executor service to shutdown

See Also:

ExecutorService.shutdown(), getShutdownAwaitTermination()

shutdownGraceful

void shutdownGraceful(ExecutorService executorService,
                      long shutdownAwaitTermination)

Shutdown the given executor service graceful at first, and then aggressively if the await termination timeout was hit.

Will try to perform an orderly shutdown by giving the running threads time to complete tasks, before going more aggressively by doing a shutdownNow(java.util.concurrent.ExecutorService) which forces a shutdown. The parameter shutdownAwaitTermination is used as timeout value waiting for orderly shutdown to complete normally, before going aggressively.

Parameters:

executorService - the executor service to shutdown

shutdownAwaitTermination - timeout in millis to wait for orderly shutdown

See Also:

ExecutorService.shutdown()

shutdownNow

List<Runnable> shutdownNow(ExecutorService executorService)

Shutdown now the given executor service aggressively.

This implementation will issues a regular shutdownNow of the executor service, ie calling ExecutorService.shutdownNow() and return.

Parameters:

executorService - the executor service to shutdown now

Returns:

list of tasks that never commenced execution

See Also:

ExecutorService.shutdownNow()

awaitTermination

boolean awaitTermination(ExecutorService executorService,
                         long shutdownAwaitTermination)
                  throws InterruptedException

Awaits the termination of the thread pool.

This implementation will log every 2nd second at INFO level that we are waiting, so the end user can see we are not hanging in case it takes longer time to terminate the pool.

Parameters:

executorService - the thread pool

shutdownAwaitTermination - time in millis to use as timeout

Returns:

true if the pool is terminated, or false if we timed out

Throws:

InterruptedException - is thrown if we are interrupted during waiting