Class ExecutorServiceCloseable
- java.lang.Object
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- com.microstrategy.webapi.utils.ExecutorServiceCloseable
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- All Implemented Interfaces:
java.lang.AutoCloseable
,java.util.concurrent.Executor
,java.util.concurrent.ExecutorService
public class ExecutorServiceCloseable extends java.lang.Object implements java.util.concurrent.ExecutorService, java.lang.AutoCloseable
AnExecutor
ExecutorServiceCloseable that is also AutoCloseable, meaning you can use it in a try with resources statement.An
Executor
that provides methods to manage termination and methods that can produce aFuture
for tracking progress of one or more asynchronous tasks.An ExecutorService can be shut down, which will cause it to reject new tasks. Two different methods are provided for shutting down an ExecutorService. The
shutdown()
method will allow previously submitted tasks to execute before terminating, while theshutdownNow()
method prevents waiting tasks from starting and attempts to stop currently executing tasks. Upon termination, an executor has no tasks actively executing, no tasks awaiting execution, and no new tasks can be submitted. An unused ExecutorService should be shut down to allow reclamation of its resources.Method submit extends base method
Executor.execute(java.lang.Runnable)
by creating and returning aFuture
that can be used to cancel execution and/or wait for completion. Methods invokeAny and invokeAll perform the most commonly useful forms of bulk execution, executing a collection of tasks and then waiting for at least one, or all, to complete. (ClassExecutorCompletionService
can be used to write customized variants of these methods.)The
Executors
class provides factory methods for the executor services provided in this package.Usage Examples
Here is a sketch of a network service in which threads in a thread pool service incoming requests. It uses the preconfiguredExecutors.newFixedThreadPool(int)
factory method:class NetworkService implements Runnable { private final ServerSocket serverSocket; private final ExecutorService pool; public NetworkService(int port, int poolSize) throws IOException { serverSocket = new ServerSocket(port); pool = Executors.newFixedThreadPool(poolSize); } public void run() { // run the service try { for (;;) { pool.execute(new Handler(serverSocket.accept())); } } catch (IOException ex) { pool.shutdown(); } } } class Handler implements Runnable { private final Socket socket; Handler(Socket socket) { this.socket = socket; } public void run() { // read and service request on socket } }
The following method shuts down an ExecutorService in two phases, first by calling shutdown to reject incoming tasks, and then calling shutdownNow, if necessary, to cancel any lingering tasks:void shutdownAndAwaitTermination(ExecutorService pool) { pool.shutdown(); // Disable new tasks from being submitted try { // Wait a while for existing tasks to terminate if (!pool.awaitTermination(60, TimeUnit.SECONDS)) { pool.shutdownNow(); // Cancel currently executing tasks // Wait a while for tasks to respond to being cancelled if (!pool.awaitTermination(60, TimeUnit.SECONDS)) System.err.println("Pool did not terminate"); } } catch (InterruptedException ie) { // (Re-)Cancel if current thread also interrupted pool.shutdownNow(); // Preserve interrupt status Thread.currentThread().interrupt(); } }
Memory consistency effects: Actions in a thread prior to the submission of a
Runnable
orCallable
task to anExecutorService
happen-before any actions taken by that task, which in turn happen-before the result is retrieved viaFuture.get()
.- Since:
- 1.5
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Constructor Summary
Constructors Constructor Description ExecutorServiceCloseable(int iThreadCount, java.lang.String iThreadPoolName)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
awaitTermination(long timeout, java.util.concurrent.TimeUnit unit)
void
close()
void
execute(java.lang.Runnable command)
<T> java.util.List<java.util.concurrent.Future<T>>
invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks)
<T> java.util.List<java.util.concurrent.Future<T>>
invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks, long timeout, java.util.concurrent.TimeUnit unit)
<T> T
invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks)
<T> T
invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks, long timeout, java.util.concurrent.TimeUnit unit)
boolean
isShutdown()
boolean
isTerminated()
void
shutdown()
java.util.List<java.lang.Runnable>
shutdownNow()
java.util.concurrent.Future<?>
submit(java.lang.Runnable task)
<T> java.util.concurrent.Future<T>
submit(java.lang.Runnable task, T result)
<T> java.util.concurrent.Future<T>
submit(java.util.concurrent.Callable<T> task)
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Method Detail
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execute
public void execute(java.lang.Runnable command)
- Specified by:
execute
in interfacejava.util.concurrent.Executor
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shutdown
public void shutdown()
- Specified by:
shutdown
in interfacejava.util.concurrent.ExecutorService
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shutdownNow
public java.util.List<java.lang.Runnable> shutdownNow()
- Specified by:
shutdownNow
in interfacejava.util.concurrent.ExecutorService
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isShutdown
public boolean isShutdown()
- Specified by:
isShutdown
in interfacejava.util.concurrent.ExecutorService
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isTerminated
public boolean isTerminated()
- Specified by:
isTerminated
in interfacejava.util.concurrent.ExecutorService
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awaitTermination
public boolean awaitTermination(long timeout, java.util.concurrent.TimeUnit unit) throws java.lang.InterruptedException
- Specified by:
awaitTermination
in interfacejava.util.concurrent.ExecutorService
- Throws:
java.lang.InterruptedException
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submit
public <T> java.util.concurrent.Future<T> submit(java.util.concurrent.Callable<T> task)
- Specified by:
submit
in interfacejava.util.concurrent.ExecutorService
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submit
public <T> java.util.concurrent.Future<T> submit(java.lang.Runnable task, T result)
- Specified by:
submit
in interfacejava.util.concurrent.ExecutorService
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submit
public java.util.concurrent.Future<?> submit(java.lang.Runnable task)
- Specified by:
submit
in interfacejava.util.concurrent.ExecutorService
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invokeAll
public <T> java.util.List<java.util.concurrent.Future<T>> invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks) throws java.lang.InterruptedException
- Specified by:
invokeAll
in interfacejava.util.concurrent.ExecutorService
- Throws:
java.lang.InterruptedException
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invokeAll
public <T> java.util.List<java.util.concurrent.Future<T>> invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks, long timeout, java.util.concurrent.TimeUnit unit) throws java.lang.InterruptedException
- Specified by:
invokeAll
in interfacejava.util.concurrent.ExecutorService
- Throws:
java.lang.InterruptedException
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invokeAny
public <T> T invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks) throws java.lang.InterruptedException, java.util.concurrent.ExecutionException
- Specified by:
invokeAny
in interfacejava.util.concurrent.ExecutorService
- Throws:
java.lang.InterruptedException
java.util.concurrent.ExecutionException
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invokeAny
public <T> T invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks, long timeout, java.util.concurrent.TimeUnit unit) throws java.lang.InterruptedException, java.util.concurrent.ExecutionException, java.util.concurrent.TimeoutException
- Specified by:
invokeAny
in interfacejava.util.concurrent.ExecutorService
- Throws:
java.lang.InterruptedException
java.util.concurrent.ExecutionException
java.util.concurrent.TimeoutException
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close
public void close()
- Specified by:
close
in interfacejava.lang.AutoCloseable
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