|
|
|
SUMMARY: NESTED | FIELD | CONSTR | METHOD DETAIL: FIELD | CONSTR | METHOD |
|
FlexDoc/Javadoc 2.0 Demo Java Doc |
Class Executors
java.util.concurrent.Executors
public class Executors
Factory and utility methods for
Executor,
ExecutorService,
ScheduledExecutorService,
ThreadFactory, and
Callable classes defined in this
package. This class supports the following kinds of methods:
- Methods that create and return an ExecutorService
set up with commonly useful configuration settings.
- Methods that create and return a ScheduledExecutorService
set up with commonly useful configuration settings.
- Methods that create and return a "wrapped" ExecutorService, that
disables reconfiguration by making implementation-specific methods
inaccessible.
- Methods that create and return a ThreadFactory
that sets newly created threads to a known state.
- Methods that create and return a Callable
out of other closure-like forms, so they can be used
in execution methods requiring Callable.
Since:
1.5
Author:
Doug Lea
Method Summary |
|
Returns a Callable object that, when
called, runs the given privileged action and returns its result.
|
|
Returns a Callable object that, when
called, runs the given privileged exception action and returns
its result.
|
|
Returns a Callable object that, when
called, runs the given task and returns null.
|
|
Returns a Callable object that, when
called, runs the given task and returns the given result.
|
|
Returns a default thread factory used to create new threads.
|
|
Creates a thread pool that creates new threads as needed, but
will reuse previously constructed threads when they are
available.
|
|
Creates a thread pool that creates new threads as needed, but
will reuse previously constructed threads when they are
available, and uses the provided
ThreadFactory to create new threads when needed.
|
|
Creates a thread pool that reuses a fixed number of threads
operating off a shared unbounded queue.
|
|
Creates a thread pool that reuses a fixed number of threads
operating off a shared unbounded queue, using the provided
ThreadFactory to create new threads when needed.
|
|
Creates a thread pool that can schedule commands to run after a
given delay, or to execute periodically.
|
|
Creates a thread pool that can schedule commands to run after a
given delay, or to execute periodically.
|
|
Creates an Executor that uses a single worker thread operating
off an unbounded queue.
|
|
Creates an Executor that uses a single worker thread operating
off an unbounded queue, and uses the provided ThreadFactory to
create a new thread when needed.
|
|
Creates a single-threaded executor that can schedule commands
to run after a given delay, or to execute periodically.
|
|
Creates a single-threaded executor that can schedule commands
to run after a given delay, or to execute periodically.
|
|
Creates a work-stealing thread pool using the number of
available processors
as its target parallelism level.
|
|
Creates a thread pool that maintains enough threads to support
the given parallelism level, and may use multiple queues to
reduce contention.
|
|
Deprecated, for removal. This method is only useful in conjunction with
the Security Manager, which is
deprecated and subject to removal in a future release.
|
|
Deprecated, for removal. This method is only useful in conjunction with
the Security Manager, which is
deprecated and subject to removal in a future release.
|
|
Deprecated, for removal. This method is only useful in conjunction with
the Security Manager, which is
deprecated and subject to removal in a future release.
|
|
Returns an object that delegates all defined ExecutorService methods to the given executor, but not any
other methods that might otherwise be accessible using
casts.
|
|
Returns an object that delegates all defined ScheduledExecutorService methods to the given executor, but
not any other methods that might otherwise be accessible using
casts.
|
Methods inherited from class java.lang. Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Creates a thread pool that reuses a fixed number of threads
operating off a shared unbounded queue. At any point, at most
nThreads threads will be active processing tasks.
If additional tasks are submitted when all threads are active,
they will wait in the queue until a thread is available.
If any thread terminates due to a failure during execution
prior to shutdown, a new one will take its place if needed to
execute subsequent tasks. The threads in the pool will exist
until it is explicitly
shutdown.
Parameters:
nThreads - the number of threads in the pool
Returns:
the newly created thread pool
Throws:
Creates a thread pool that maintains enough threads to support
the given parallelism level, and may use multiple queues to
reduce contention. The parallelism level corresponds to the
maximum number of threads actively engaged in, or available to
engage in, task processing. The actual number of threads may
grow and shrink dynamically. A work-stealing pool makes no
guarantees about the order in which submitted tasks are
executed.
Parameters:
parallelism - the targeted parallelism level
Returns:
the newly created thread pool
Throws:
Since:
1.8
Creates a work-stealing thread pool using the number of
available processors
as its target parallelism level.
Returns:
the newly created thread pool
Since:
1.8
See Also:
Creates a thread pool that reuses a fixed number of threads
operating off a shared unbounded queue, using the provided
ThreadFactory to create new threads when needed. At any point,
at most
nThreads threads will be active processing
tasks. If additional tasks are submitted when all threads are
active, they will wait in the queue until a thread is
available. If any thread terminates due to a failure during
execution prior to shutdown, a new one will take its place if
needed to execute subsequent tasks. The threads in the pool will
exist until it is explicitly
shutdown.
Parameters:
nThreads - the number of threads in the pool
threadFactory - the factory to use when creating new threads
Returns:
the newly created thread pool
Throws:
Creates an Executor that uses a single worker thread operating
off an unbounded queue. (Note however that if this single
thread terminates due to a failure during execution prior to
shutdown, a new one will take its place if needed to execute
subsequent tasks.) Tasks are guaranteed to execute
sequentially, and no more than one task will be active at any
given time. Unlike the otherwise equivalent
newFixedThreadPool(1) the returned executor is
guaranteed not to be reconfigurable to use additional threads.
Returns:
the newly created single-threaded Executor
Creates an Executor that uses a single worker thread operating
off an unbounded queue, and uses the provided ThreadFactory to
create a new thread when needed. Unlike the otherwise
equivalent
newFixedThreadPool(1, threadFactory) the
returned executor is guaranteed not to be reconfigurable to use
additional threads.
Parameters:
threadFactory - the factory to use when creating new threads
Returns:
the newly created single-threaded Executor
Throws:
Creates a thread pool that creates new threads as needed, but
will reuse previously constructed threads when they are
available. These pools will typically improve the performance
of programs that execute many short-lived asynchronous tasks.
Calls to
execute will reuse previously constructed
threads if available. If no existing thread is available, a new
thread will be created and added to the pool. Threads that have
not been used for sixty seconds are terminated and removed from
the cache. Thus, a pool that remains idle for long enough will
not consume any resources. Note that pools with similar
properties but different details (for example, timeout parameters)
may be created using
ThreadPoolExecutor constructors.
Returns:
the newly created thread pool
Creates a thread pool that creates new threads as needed, but
will reuse previously constructed threads when they are
available, and uses the provided
ThreadFactory to create new threads when needed.
Parameters:
threadFactory - the factory to use when creating new threads
Returns:
the newly created thread pool
Throws:
newSingleThreadScheduledExecutor
Creates a single-threaded executor that can schedule commands
to run after a given delay, or to execute periodically.
(Note however that if this single
thread terminates due to a failure during execution prior to
shutdown, a new one will take its place if needed to execute
subsequent tasks.) Tasks are guaranteed to execute
sequentially, and no more than one task will be active at any
given time. Unlike the otherwise equivalent
newScheduledThreadPool(1) the returned executor is
guaranteed not to be reconfigurable to use additional threads.
Returns:
the newly created scheduled executor
newSingleThreadScheduledExecutor
Creates a single-threaded executor that can schedule commands
to run after a given delay, or to execute periodically. (Note
however that if this single thread terminates due to a failure
during execution prior to shutdown, a new one will take its
place if needed to execute subsequent tasks.) Tasks are
guaranteed to execute sequentially, and no more than one task
will be active at any given time. Unlike the otherwise
equivalent
newScheduledThreadPool(1, threadFactory)
the returned executor is guaranteed not to be reconfigurable to
use additional threads.
Parameters:
threadFactory - the factory to use when creating new threads
Returns:
the newly created scheduled executor
Throws:
Creates a thread pool that can schedule commands to run after a
given delay, or to execute periodically.
Parameters:
corePoolSize - the number of threads to keep in the pool,
even if they are idle
Returns:
the newly created scheduled thread pool
Throws:
Creates a thread pool that can schedule commands to run after a
given delay, or to execute periodically.
Parameters:
corePoolSize - the number of threads to keep in the pool,
even if they are idle
threadFactory - the factory to use when the executor
creates a new thread
Returns:
the newly created scheduled thread pool
Throws:
unconfigurableExecutorService
Returns an object that delegates all defined
ExecutorService methods to the given executor, but not any
other methods that might otherwise be accessible using
casts. This provides a way to safely "freeze" configuration and
disallow tuning of a given concrete implementation.
Parameters:
executor - the underlying implementation
Returns:
an ExecutorService instance
Throws:
unconfigurableScheduledExecutorService
Returns an object that delegates all defined
ScheduledExecutorService methods to the given executor, but
not any other methods that might otherwise be accessible using
casts. This provides a way to safely "freeze" configuration and
disallow tuning of a given concrete implementation.
Parameters:
executor - the underlying implementation
Returns:
a ScheduledExecutorService instance
Throws:
Returns a default thread factory used to create new threads.
This factory creates all new threads used by an Executor in the
same
ThreadGroup. If there is a
SecurityManager, it uses the group of
System.getSecurityManager(), else the group of the thread
invoking this
defaultThreadFactory method. Each new
thread is created as a non-daemon thread with priority set to
the smaller of
Thread.NORM_PRIORITY and the maximum
priority permitted in the thread group. New threads have names
accessible via
Thread.getName() of
pool-N-thread-M, where
N is the sequence
number of this factory, and
M is the sequence number
of the thread created by this factory.
Returns:
a thread factory
Deprecated, for removal. This method is only useful in conjunction with
the Security Manager, which is
deprecated and subject to removal in a future release.
Consequently, this method is also deprecated and subject to
removal. There is no replacement for the Security Manager or this
method.
Returns a thread factory used to create new threads that
have the same permissions as the current thread.
This factory creates threads with the same settings as
defaultThreadFactory(), additionally setting the
AccessControlContext and contextClassLoader of new threads to
be the same as the thread invoking this
privilegedThreadFactory method. A new
privilegedThreadFactory can be created within an
AccessController.doPrivileged
action setting the current thread's access control context to
create threads with the selected permission settings holding
within that action.
Note that while tasks running within such threads will have
the same access control and class loader settings as the
current thread, they need not have the same ThreadLocal or InheritableThreadLocal values. If necessary,
particular values of thread locals can be set or reset before
any task runs in ThreadPoolExecutor subclasses using
ThreadPoolExecutor.beforeExecute(Thread, Runnable).
Also, if it is necessary to initialize worker threads to have
the same InheritableThreadLocal settings as some other
designated thread, you can create a custom ThreadFactory in
which that thread waits for and services requests to create
others that will inherit its values.
Returns:
a thread factory
Throws:
AccessControlException - if the current access control
context does not have permission to both get and set context
class loader
Returns a
Callable object that, when
called, runs the given task and returns the given result. This
can be useful when applying methods requiring a
Callable to an otherwise resultless action.
Type Parameters:
T - the type of the result
Parameters:
task - the task to run
result - the result to return
Returns:
a callable object
Throws:
Returns a
Callable object that, when
called, runs the given task and returns
null.
Parameters:
task - the task to run
Returns:
a callable object
Throws:
Returns a
Callable object that, when
called, runs the given privileged action and returns its result.
Parameters:
action - the privileged action to run
Returns:
a callable object
Throws:
Returns a
Callable object that, when
called, runs the given privileged exception action and returns
its result.
Parameters:
action - the privileged exception action to run
Returns:
a callable object
Throws:
Deprecated, for removal. This method is only useful in conjunction with
the Security Manager, which is
deprecated and subject to removal in a future release.
Consequently, this method is also deprecated and subject to
removal. There is no replacement for the Security Manager or this
method.
Returns a
Callable object that will, when called,
execute the given
callable under the current access
control context. This method should normally be invoked within
an
AccessController.doPrivileged
action to create callables that will, if possible, execute
under the selected permission settings holding within that
action; or if not possible, throw an associated
AccessControlException.
Type Parameters:
T - the type of the callable's result
Parameters:
callable - the underlying task
Returns:
a callable object
Throws:
privilegedCallableUsingCurrentClassLoader
public static < T> Callable< T> privilegedCallableUsingCurrentClassLoader |
|
Deprecated, for removal. This method is only useful in conjunction with
the Security Manager, which is
deprecated and subject to removal in a future release.
Consequently, this method is also deprecated and subject to
removal. There is no replacement for the Security Manager or this
method.
Returns a
Callable object that will, when called,
execute the given
callable under the current access
control context, with the current context class loader as the
context class loader. This method should normally be invoked
within an
AccessController.doPrivileged
action to create callables that will, if possible, execute
under the selected permission settings holding within that
action; or if not possible, throw an associated
AccessControlException.
Type Parameters:
T - the type of the callable's result
Parameters:
callable - the underlying task
Returns:
a callable object
Throws:
|
|
|
SUMMARY: NESTED | FIELD | CONSTR | METHOD DETAIL: FIELD | CONSTR | METHOD |
|
FlexDoc/Javadoc 2.0 Demo Java Doc |
FlexDoc/Javadoc is a template-driven programming tool for rapid development of any Javadoc-based Java API documentation generators (i.e. doclets). If you need to customize your Javadoc without writing a full-blown doclet from scratch,
FlexDoc/Javadoc may be the only tool able to help you! Find out more at
www.flexdoc.xyz