MTLCounter
An individual counter a GPU device lists within one of its counter sets.
Declaration
protocol MTLCounter : NSObjectProtocol, SendableOverview
You can determine which counters a GPU supports within a counter set (see MTLCounterSet) by checking the elements of its counters property. A counter’s name property typically matches one of the common counter set names that MTLCommonCounter defines. For more information, see Confirming which counters and counter sets a GPU supports.