IExecutorService Interface
Definition
Important
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An Executor that provides methods to manage termination and
methods that can produce a Future for tracking progress of
one or more asynchronous tasks.
[Android.Runtime.Register("java/util/concurrent/ExecutorService", "", "Java.Util.Concurrent.IExecutorServiceInvoker")]
public interface IExecutorService : IDisposable, Java.Interop.IJavaPeerable, Java.Util.Concurrent.IExecutor[<Android.Runtime.Register("java/util/concurrent/ExecutorService", "", "Java.Util.Concurrent.IExecutorServiceInvoker")>]
type IExecutorService = interface
interface IExecutor
interface IJavaObject
interface IDisposable
interface IJavaPeerable- Derived
- Attributes
- Implements
Remarks
An Executor that provides methods to manage termination and methods that can produce a Future 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 the #shutdownNow 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(Runnable) by creating and returning a Future 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. (Class ExecutorCompletionService can be used to write customized variants of these methods.)
The Executors class provides factory methods for the executor services provided in this package.
<h2>Usage Examples</h2>
Here is a sketch of a network service in which threads in a thread pool service incoming requests. It uses the preconfigured Executors#newFixedThreadPool factory method:
{@code
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:
{@code
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 ex) {
// (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 or Callable task to an ExecutorService<i>happen-before</i> any actions taken by that task, which in turn happen-before the result is retrieved via Future.get().
Added in 1.5.
Java documentation for java.util.concurrent.ExecutorService.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Properties
| Handle |
Gets the JNI value of the underlying Android object. (Inherited from IJavaObject) |
| IsShutdown |
Returns |
| IsTerminated |
Returns |
| JniIdentityHashCode |
Returns the value of |
| JniManagedPeerState |
State of the managed peer. (Inherited from IJavaPeerable) |
| JniPeerMembers |
Member access and invocation support. (Inherited from IJavaPeerable) |
| PeerReference |
Returns a JniObjectReference of the wrapped Java object instance. (Inherited from IJavaPeerable) |
Methods
| AwaitTermination(Int64, TimeUnit) |
Blocks until all tasks have completed execution after a shutdown request, or the timeout occurs, or the current thread is interrupted, whichever happens first. |
| Disposed() |
Called when the instance has been disposed. (Inherited from IJavaPeerable) |
| DisposeUnlessReferenced() |
If there are no outstanding references to this instance, then
calls |
| Execute(IRunnable) |
Executes the given command at some time in the future. (Inherited from IExecutor) |
| Finalized() |
Called when the instance has been finalized. (Inherited from IJavaPeerable) |
| InvokeAll(ICollection, Int64, TimeUnit) |
Executes the given tasks, returning a list of Futures holding their status and results when all complete or the timeout expires, whichever happens first. |
| InvokeAll(ICollection) |
Executes the given tasks, returning a list of Futures holding their status and results when all complete. |
| InvokeAny(ICollection, Int64, TimeUnit) |
Executes the given tasks, returning the result of one that has completed successfully (i. |
| InvokeAny(ICollection) |
Executes the given tasks, returning the result of one that has completed successfully (i. |
| SetJniIdentityHashCode(Int32) |
Set the value returned by |
| SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from IJavaPeerable) |
| SetPeerReference(JniObjectReference) |
Set the value returned by |
| Shutdown() |
Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted. |
| ShutdownNow() |
Attempts to stop all actively executing tasks, halts the processing of waiting tasks, and returns a list of the tasks that were awaiting execution. |
| Submit(ICallable) |
Submits a value-returning task for execution and returns a Future representing the pending results of the task. |
| Submit(IRunnable, Object) |
Submits a Runnable task for execution and returns a Future representing that task. |
| Submit(IRunnable) |
Submits a Runnable task for execution and returns a Future representing that task. |
| UnregisterFromRuntime() |
Unregister this instance so that the runtime will not return it from future Java.Interop.JniRuntime+JniValueManager.PeekValue invocations. (Inherited from IJavaPeerable) |