The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
COUNTER_FLAG_PERSIST
      (integer)
     COUNTER_FLAG_SAVE
      (integer)
     COUNTER_FLAG_NO_OVERWRITE
      (integer)
     COUNTER_META_NAME
      (string)
     COUNTER_META_IS_PERISTENT
      (string)
     COUNTER_FLAG_PERSIST flag).
      
     COUNTER_RESET_NEVER
      (integer)
     COUNTER_RESET_PER_LOAD
      (integer)
     COUNTER_RESET_PER_REQUEST
      (integer)