DoubleAccumulator Class
Definition
Important
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One or more variables that together maintain a running double
value updated using a supplied function.
[Android.Runtime.Register("java/util/concurrent/atomic/DoubleAccumulator", ApiSince=24, DoNotGenerateAcw=true)]
public class DoubleAccumulator : Java.Lang.Number, IDisposable, Java.Interop.IJavaPeerable[<Android.Runtime.Register("java/util/concurrent/atomic/DoubleAccumulator", ApiSince=24, DoNotGenerateAcw=true)>]
type DoubleAccumulator = class
inherit Number
interface ISerializable
interface IJavaObject
interface IDisposable
interface IJavaPeerable- Inheritance
- Attributes
- Implements
Remarks
One or more variables that together maintain a running double value updated using a supplied function. When updates (method #accumulate) are contended across threads, the set of variables may grow dynamically to reduce contention. Method #get (or, equivalently, #doubleValue) returns the current value across the variables maintaining updates.
This class is usually preferable to alternatives when multiple threads update a common value that is used for purposes such as summary statistics that are frequently updated but less frequently read.
The supplied accumulator function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. For predictable results, the accumulator function should be commutative and associative within the floating point tolerance required in usage contexts. The function is applied with an existing value (or identity) as one argument, and a given update as the other argument. For example, to maintain a running maximum value, you could supply Double::max along with Double.NEGATIVE_INFINITY as the identity. The order of accumulation within or across threads is not guaranteed. Thus, this class may not be applicable if numerical stability is required, especially when combining values of substantially different orders of magnitude.
Class DoubleAdder provides analogs of the functionality of this class for the common special case of maintaining sums. The call new DoubleAdder() is equivalent to new DoubleAccumulator((x, y) -> x + y, 0.0).
This class extends Number, but does <em>not</em> define methods such as equals, hashCode and compareTo because instances are expected to be mutated, and so are not useful as collection keys.
Added in 1.8.
Java documentation for java.util.concurrent.atomic.DoubleAccumulator.
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
| Name | Description |
|---|---|
| DoubleAccumulator(IDoubleBinaryOperator, Double) |
Creates a new instance using the given accumulator function and identity element. |
| DoubleAccumulator(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
Properties
| Name | Description |
|---|---|
| Class |
Returns the runtime class of this |
| Handle |
The handle to the underlying Android instance. (Inherited from Object) |
| JniIdentityHashCode |
Gets the identity hash code assigned to this Java peer by the interop runtime. (Inherited from Object) |
| JniPeerMembers |
Gets the JNI metadata used to invoke members of this Java peer. |
| PeerReference |
Gets the JNI object reference for this Java peer. (Inherited from Object) |
| ThenReset |
Equivalent in effect to |
| 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
| Name | Description |
|---|---|
| Accumulate(Double) |
Updates with the given value. |
| ByteValue() |
Returns the value of the specified number as a |
| Clone() |
Creates and returns a copy of this object. (Inherited from Object) |
| Dispose() |
Releases the resources held by this Java peer. (Inherited from Object) |
| Dispose(Boolean) |
Releases the resources held by this Java peer. (Inherited from Object) |
| DoubleValue() |
Equivalent to |
| Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
| FloatValue() |
Returns the #get current value as a |
| Get() |
Returns the current value. |
| GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
| IntValue() |
Returns the #get current value as an |
| 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) |
| LongValue() |
Returns the #get current value as a |
| 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) |
| Reset() |
Resets variables maintaining updates to the identity value. |
| SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
| ShortValue() |
Returns the value of the specified number as a |
| ToArray<T>() |
Creates a managed array from this Java array wrapper. (Inherited from Object) |
| ToString() |
Returns a string representation of the object. (Inherited from Object) |
| UnregisterFromRuntime() |
Unregisters this Java peer from the interop runtime. (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
| Name | Description |
|---|---|
| IJavaPeerable.Disposed() |
Notifies the interop runtime that this managed peer has been disposed. (Inherited from Object) |
| IJavaPeerable.DisposeUnlessReferenced() |
Releases this Java peer unless it is retained by another managed reference. (Inherited from Object) |
| IJavaPeerable.Finalized() |
Notifies the interop runtime that this managed peer has been finalized. (Inherited from Object) |
| IJavaPeerable.JniManagedPeerState |
Gets the state that describes the relationship between this managed peer and its JNI reference. (Inherited from Object) |
| IJavaPeerable.SetJniIdentityHashCode(Int32) |
Sets the interop identity hash code for this Java peer. (Inherited from Object) |
| IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) |
Sets the managed and JNI peer state for this Java peer. (Inherited from Object) |
| IJavaPeerable.SetPeerReference(JniObjectReference) |
Sets the JNI object reference used by this managed peer. (Inherited from Object) |
Extension Methods
| Name | Description |
|---|---|
| GetJniTypeName(IJavaPeerable) |
Gets the JNI name of the type of the instance |
| JavaAs<TResult>(IJavaPeerable) |
Try to coerce |
| JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
| JavaCast<TResult>(IJavaObject) | |
| TryJavaCast<TResult>(IJavaPeerable, TResult) |
Try to coerce |