ObservableCounterInterface
            
            extends
                            AsynchronousInstrument                    
                
            in
            
        
    
        
            Marker interface for asynchronous instruments.
Table of Contents
Methods
- isEnabled() : bool
- Determine if the instrument is enabled. Instrumentation authors SHOULD call this API each time they record a measurement.
- observe() : ObservableCallbackInterface
Methods
isEnabled()
Determine if the instrument is enabled. Instrumentation authors SHOULD call this API each time they record a measurement.
    public
                    isEnabled() : bool
    MUST return false if:
- The MeterConfig of the Meter used to create the instrument has parameter disabled=true
- All resolved views for the instrument are configured with the Drop Aggregation
Tags
Return values
boolobserve()
    public
                    observe(callable(ObserverInterface): void $callback) : ObservableCallbackInterface
    Parameters
- $callback : callable(ObserverInterface): void
- 
                    function responsible for reporting the measurements (as absolute values) 
Return values
ObservableCallbackInterface —token to detach callback