Exchanger Class

Reference

Definition

Namespace:: Java.Util.Concurrent

Assembly:: Mono.Android.dll

Important

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A synchronization point at which threads can pair and swap elements within pairs.

[Android.Runtime.Register("java/util/concurrent/Exchanger", DoNotGenerateAcw=true)]
[Java.Interop.JavaTypeParameters(new System.String[] { "V" })]
public class Exchanger : Java.Lang.Object

[<Android.Runtime.Register("java/util/concurrent/Exchanger", DoNotGenerateAcw=true)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "V" })>]
type Exchanger = class
    inherit Object

Inheritance: Object

Object
Exchanger

Attributes: RegisterAttribute JavaTypeParametersAttribute

Remarks

A synchronization point at which threads can pair and swap elements within pairs. Each thread presents some object on entry to the #exchange exchange method, matches with a partner thread, and receives its partner's object on return. An Exchanger may be viewed as a bidirectional form of a SynchronousQueue. Exchangers may be useful in applications such as genetic algorithms and pipeline designs.

<b>Sample Usage:</b> Here are the highlights of a class that uses an Exchanger to swap buffers between threads so that the thread filling the buffer gets a freshly emptied one when it needs it, handing off the filled one to the thread emptying the buffer.

{@code
            class FillAndEmpty {
              Exchanger<DataBuffer> exchanger = new Exchanger<>();
              DataBuffer initialEmptyBuffer = ...; // a made-up type
              DataBuffer initialFullBuffer = ...;

              class FillingLoop implements Runnable {
                public void run() {
                  DataBuffer currentBuffer = initialEmptyBuffer;
                  try {
                    while (currentBuffer != null) {
                      addToBuffer(currentBuffer);
                      if (currentBuffer.isFull())
                        currentBuffer = exchanger.exchange(currentBuffer);
                    }
                  } catch (InterruptedException ex) { ... handle ...}
                }
              }

              class EmptyingLoop implements Runnable {
                public void run() {
                  DataBuffer currentBuffer = initialFullBuffer;
                  try {
                    while (currentBuffer != null) {
                      takeFromBuffer(currentBuffer);
                      if (currentBuffer.isEmpty())
                        currentBuffer = exchanger.exchange(currentBuffer);
                    }
                  } catch (InterruptedException ex) { ... handle ...}
                }
              }

              void start() {
                new Thread(new FillingLoop()).start();
                new Thread(new EmptyingLoop()).start();
              }
            }}

Memory consistency effects: For each pair of threads that successfully exchange objects via an Exchanger, actions prior to the exchange() in each thread <i>happen-before</i> those subsequent to a return from the corresponding exchange() in the other thread.

Added in 1.5.

Java documentation for java.util.concurrent.Exchanger.

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.

Constructors

Exchanger()	Creates a new Exchanger.
Exchanger(IntPtr, JniHandleOwnership)	A constructor used when creating managed representations of JNI objects; called by the runtime.

Properties

Class	Returns the runtime class of this `Object`. (Inherited from Object)
Handle	The handle to the underlying Android instance. (Inherited from Object)
JniIdentityHashCode	(Inherited from Object)
JniPeerMembers
PeerReference	(Inherited from Object)
ThresholdClass	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.
ThresholdType	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.

Methods

Clone()	Creates and returns a copy of this object. (Inherited from Object)
Dispose()	(Inherited from Object)
Dispose(Boolean)	(Inherited from Object)
Equals(Object)	Indicates whether some other object is "equal to" this one. (Inherited from Object)
Exchange(Object, Int64, TimeUnit)	Waits for another thread to arrive at this exchange point (unless the current thread is Thread#interrupt interrupted or the specified waiting time elapses), and then transfers the given object to it, receiving its object in return.
Exchange(Object)	Waits for another thread to arrive at this exchange point (unless the current thread is Thread#interrupt interrupted), and then transfers the given object to it, receiving its object in return.
GetHashCode()	Returns a hash code value for the object. (Inherited from Object)
JavaFinalize()	Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object)
Notify()	Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object)
NotifyAll()	Wakes up all threads that are waiting on this object's monitor. (Inherited from Object)
SetHandle(IntPtr, JniHandleOwnership)	Sets the Handle property. (Inherited from Object)
ToArray<T>()	(Inherited from Object)
ToString()	Returns a string representation of the object. (Inherited from Object)
UnregisterFromRuntime()	(Inherited from Object)
Wait()	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object)
Wait(Int64, Int32)	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object)
Wait(Int64)	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object)

Explicit Interface Implementations

IJavaPeerable.Disposed()	(Inherited from Object)
IJavaPeerable.DisposeUnlessReferenced()	(Inherited from Object)
IJavaPeerable.Finalized()	(Inherited from Object)
IJavaPeerable.JniManagedPeerState	(Inherited from Object)
IJavaPeerable.SetJniIdentityHashCode(Int32)	(Inherited from Object)
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from Object)
IJavaPeerable.SetPeerReference(JniObjectReference)	(Inherited from Object)

Extension Methods

JavaCast<TResult>(IJavaObject)	Performs an Android runtime-checked type conversion.
JavaCast<TResult>(IJavaObject)
GetJniTypeName(IJavaPeerable)

Applies to

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