SharedResourceHolder (Flink : Python 1.19.3-cp2 API)

java.lang.Object
- org.apache.beam.vendor.grpc.v1p48p1.io.grpc.internal.SharedResourceHolder

```
@ThreadSafe
public final class SharedResourceHolder
extends Object
```
A holder for shared resource singletons.
Components like client channels and servers need certain resources, e.g. a thread pool, to run. If the user has not provided such resources, these components will use a default one, which is shared as a static resource. This class holds these default resources and manages their life-cycles.
A resource is identified by the reference of a SharedResourceHolder.Resource object, which is typically a singleton, provided to the get() and release() methods. Each Resource object (not its class) maps to an object cached in the holder.
Resources are ref-counted and shut down after a delay when the ref-count reaches zero.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static interface SharedResourceHolder.Resource<T>
Defines a resource, and the way to create and destroy instances of it.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static <T> T`	`get(SharedResourceHolder.Resource<T> resource)`	Try to get an existing instance of the given resource.
`static <T> T`	`release(SharedResourceHolder.Resource<T> resource, T instance)`	Releases an instance of the given resource.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - get
```
public static <T> T get(SharedResourceHolder.Resource<T> resource)
```
    Try to get an existing instance of the given resource. If an instance does not exist, create a new one with the given factory.
    
    Parameters:
    
    resource - the singleton object that identifies the requested static resource
  - release
```
public static <T> T release(SharedResourceHolder.Resource<T> resource,
                            T instance)
```
    Releases an instance of the given resource.
    The instance must have been obtained from get(Resource). Otherwise will throw IllegalArgumentException.
    Caller must not release a reference more than once. It's advisory that you clear the reference to the instance with the null returned by this method.
    
    Parameters:
    
    resource - the singleton Resource object that identifies the released static resource
    
    instance - the released static resource
    
    Returns:
    
    a null which the caller can use to clear the reference to that instance.