SyncFence Class

Definition

Namespace:

Android.Hardware

Assembly:

Mono.Android.dll

A SyncFence represents a synchronization primitive which signals when hardware units have completed work on a particular resource.

[Android.Runtime.Register("android/hardware/SyncFence", ApiSince=33, DoNotGenerateAcw=true)]
public sealed class SyncFence : Java.Lang.Object, Android.OS.IParcelable, IDisposable, Java.Interop.IJavaPeerable, Java.Lang.IAutoCloseable

[<Android.Runtime.Register("android/hardware/SyncFence", ApiSince=33, DoNotGenerateAcw=true)>]
type SyncFence = class
    inherit Object
    interface IParcelable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable
    interface IAutoCloseable

Inheritance

Object

Object

SyncFence

Attributes

RegisterAttribute

Implements

IParcelable IJavaObject IJavaPeerable IAutoCloseable IDisposable

Remarks

A SyncFence represents a synchronization primitive which signals when hardware units have completed work on a particular resource. They initially start in an unsignaled state and make a one-time transition to either a signaled or error state. SyncFences are created by various device APIs in response to submitting tasks to the device. They cannot be created nor signaled by userspace. As a result, this means that a SyncFence will make always make forward progress.

SyncFence's generally come in one of two varieties. "Presentation fences" refer to a SyncFence when the writing to a buffer has finished. "Release fences" then refer to when the reading from a buffer has finished.

For example, a GPU rendering to a framebuffer may generate a synchronization fence, e.g., an EGLSync or VkFence, which signals when rendering has completed. Once the fence signals, then the backing storage for the framebuffer may be safely read from, such as for display or for media encoding. This would be referred to as a "presentation fence."

Similarly when using an android.media.ImageWriter it is possible that an android.media.Image returned by ImageWriter#dequeueInputImage() may already have a Image#getFence() fence set on it. This would be what is referred to as either a "release fence" or an "acqurie fence" and indicates the fence that the writer must wait on before writing to the underlying buffer. In the case of ImageWriter this is done automatically when eg Image#getPlanes() is called, however when using Image#getHardwareBuffer() it is the caller's responsibility to ensure the release fence has signaled before writing to the buffer.

Java documentation for android.hardware.SyncFence.

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.

Fields

SignalTimeInvalid	An invalid signal time.
SignalTimePending	A pending signal time.

Properties

Class	Returns the runtime class of this Object. (Inherited from Object)
Creator
Handle	The handle to the underlying Android instance. (Inherited from Object)
IsValid	Checks if the SyncFile object is valid.
JniIdentityHashCode	(Inherited from Object)
JniPeerMembers
PeerReference	(Inherited from Object)
SignalTime	Returns the time in nanoseconds that the fence signaled in the CLOCK_MONOTONIC time domain.
ThresholdClass	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. (Inherited from Object)
ThresholdType	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. (Inherited from Object)

Methods

Await(Duration)	Waits for a SyncFence to signal for up to the timeout duration.
AwaitForever()	Waits forever for a SyncFence to signal.
Clone()	Creates and returns a copy of this object. (Inherited from Object)
Close()	Close the SyncFence.
DescribeContents()
Dispose()	(Inherited from Object)
Dispose(Boolean)	(Inherited from Object)
Equals(Object)	Indicates whether some other object is "equal to" this one. (Inherited from Object)
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)	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, 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)
WriteToParcel(Parcel, ParcelableWriteFlags)	Flatten this object into a Parcel.

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)