SyncFence Class
Definition
Important
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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
- Attributes
- Implements
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.
Constructors
| Name | Description |
|---|---|
| SyncFence(SyncFence) |
Creates a copy of the SyncFence from an existing one. |
Fields
| Name | Description |
|---|---|
| SignalTimeInvalid |
An invalid signal time. |
| SignalTimePending |
A pending signal time. |
Properties
| Name | Description |
|---|---|
| Class |
Returns the runtime class of this |
| Creator | |
| Handle |
The handle to the underlying Android instance. (Inherited from Object) |
| IsValid |
Checks if the SyncFile object is valid. |
| JniIdentityHashCode |
Gets the identity hash code assigned to this Java peer by the interop runtime. (Inherited from Object) |
| JniPeerMembers | |
| PeerReference |
Gets the JNI object reference for this Java peer. (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
| Name | Description |
|---|---|
| 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() |
Releases the resources held by this Java peer. (Inherited from Object) |
| Dispose(Boolean) |
Releases the resources held by this Java peer. (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>() |
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) |
| WriteToParcel(Parcel, ParcelableWriteFlags) |
Flatten this object into a Parcel. |
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 |