ResourceContext (Resource Management )

All Superinterfaces:

AutoCloseable
```
public interface ResourceContext
extends AutoCloseable
```
A set of ResourceMeters that accumulate resource usage by threads. A ResourceContext can be associated with zero or more threads. The ResourceContextFactory.getThreadContext() and bindThreadContext() methods respectively get and set the association between the current thread and a ResourceContext.
New threads are implicitly bound to the ResourceContext of the thread invoking new Thread. The Thread's Runnable should explicitly bind to the desired context as required.
Each meter is identified by a ResourceType. Resource meters are created with the desired behavior and added to the context. The semantics of a particular meter are specified by each ResourceMeter subtype. Resource implementations locate the appropriate meter using getMeter(ResourceType). The ResourceRequest is obtained by getResourceRequest(ResourceType).

Since:

8u40

See Also:

ResourceContextFactory, ResourceMeter

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default void`	`addResourceMeter(ResourceMeter meter)` Add a ResourceMeter.
`default ResourceContext`	`bindThreadContext()` Binds the ResourceContext to the current thread.
`default Stream<Thread>`	`boundThreads()` Returns a Stream of threads bound to the ResourceContext.
`void`	`close()` Close the ResourceContext, unbinding from all threads and removing all meters.
`ResourceMeter`	`getMeter(ResourceType type)` Return the ResourceMeter for the ResourceType.
`String`	`getName()` Return the name of the ResourceContext.
`ResourceRequest`	`getResourceRequest(ResourceType type)` Returns the ResourceRequest in the ResourceContext that handles requests to allocate or release for the ResourceType.
`Stream<ResourceMeter>`	`meters()` Returns a Stream of ResourceMeters in the ResourceContext.
`default boolean`	`removeResourceMeter(ResourceMeter meter)` Remove the ResourceMeter from the ResourceContext.
`default void`	`requestAccurateUpdate(ResourceAccuracy accuracy)` Request an update of the metrics for the ResourceContext.
`static ResourceContext`	`unbindThreadContext()` Unbind the current thread from the ResourceContext.

- Method Detail
  - close
```
void close()
```
    Close the ResourceContext, unbinding from all threads and removing all meters. The value and allocated values of meters is retained and included in the TotalsResourceContext. After close the ResourceContext behaves as if it has no ResourceMeters, ResourceMeters cannot be added, and it cannot be bound to a thread. Closing a closed ResourceContext has no effect.
    
    Specified by:
    
    close in interface AutoCloseable
  - getName
```
String getName()
```
    Return the name of the ResourceContext.
    
    Returns:
    
    the name of the ResourceContext
  - bindThreadContext
```
default ResourceContext bindThreadContext()
```
    Binds the ResourceContext to the current thread.
    
    Returns:
    
    the ResourceContext the thread was bound to; the unassigned context is returned if the thread is otherwise not bound
    
    Throws:
    
    UnsupportedOperationException - if the ResourceContext does not support binding
  - unbindThreadContext
```
static ResourceContext unbindThreadContext()
```
    Unbind the current thread from the ResourceContext. The thread is implicitly bound to the unassigned context.
    
    Returns:
    
    the ResourceContext the thread was bound to; the unassigned context is returned if the thread is otherwise not bound
    
    Throws:
    
    UnsupportedOperationException - if the ResourceContext does not support unbinding
  - boundThreads
```
default Stream<Thread> boundThreads()
```
    Returns a Stream of threads bound to the ResourceContext. The Threads bound to a ResourceContext is fluid and may change at any time. If thread pooling is in use a Thread may be bound to different ResourceContexts at different times and may change dynamically.
    
    Returns:
    
    a Stream of the threads bound to the ResourceContext
    
    Throws:
    
    UnsupportedOperationException - if the ResourceContext does not maintain a set of Threads
  - getResourceRequest
```
ResourceRequest getResourceRequest(ResourceType type)
```
    Returns the ResourceRequest in the ResourceContext that handles requests to allocate or release for the ResourceType.
    
    Parameters:
    
    type - the ResourceType of the resource making the request
    
    Returns:
    
    a ResourceRequest; null if the ResourceContext is not counting metrics for the resource or the meter does not implement ResourceRequest
  - addResourceMeter
```
default void addResourceMeter(ResourceMeter meter)
```
    Add a ResourceMeter. ResourceMeters must have unique ResourceTypes within a ResourceContext.
    
    Parameters:
    
    meter - a resource meter
    
    Throws:
    
    IllegalArgumentException - if the ResourceContext contains a ResourceMeter with the same ResourceType
    
    UnsupportedOperationException - if the ResourceContext does not support adding or removing ResourceMeters or if the ResourceType is not supported
  - removeResourceMeter
```
default boolean removeResourceMeter(ResourceMeter meter)
```
    Remove the ResourceMeter from the ResourceContext. Note that this does not actually deactivate the meter, but merely excises it from the scope of the current context.
    
    Parameters:
    
    meter - the ResourceMeter to remove
    
    Returns:
    
    true if an element was removed as a result of this call
    
    Throws:
    
    UnsupportedOperationException - if the ResourceContext does not support adding or removing Meters
  - getMeter
```
ResourceMeter getMeter(ResourceType type)
```
    Return the ResourceMeter for the ResourceType.
    
    Parameters:
    
    type - a ResourceType
    
    Returns:
    
    the ResourceMeter for the type or null if none
  - meters
```
Stream<ResourceMeter> meters()
```
    Returns a Stream of ResourceMeters in the ResourceContext.
    
    Returns:
    
    stream of the ResourceMeters
  - requestAccurateUpdate
```
default void requestAccurateUpdate(ResourceAccuracy accuracy)
```
    Request an update of the metrics for the ResourceContext. If the accuracy of the information provided for this ResourceContext is less than the requested accuracy, the implementation starts a computation that will delivery the requested accuracy. Computing more accurate measurements may take some time. For example, it may be necessary to scan the heap to determine more accurately how much of the heap is retained to deliver an updated HEAP_RETAINED amount. When the computation is completed, the updated values are reported through the ResourceMeters in the ResourceContext. Only values that change are reported and use the normal ResourceMeter granularity and notification mechanisms. The resourceId.getAccuracy method returns the accuracy.
    
    Parameters:
    
    accuracy - the requested accuracy

Interface ResourceContext

Method Summary

Method Detail

close

getName

bindThreadContext

unbindThreadContext

boundThreads

getResourceRequest

addResourceMeter

removeResourceMeter

getMeter

meters

requestAccurateUpdate