src/code/early-pcounter.lisp

   1 ;;;; PCOUNTERs
   2 ;;;;
   3 ;;;; a PCOUNTER is used to represent an unsigned integer quantity which
   4 ;;;; can grow bigger than a fixnum, but typically does so, if at all,
   5 ;;;; in many small steps, where we don't want to cons on every step.
   6 ;;;; Such quantities typically arise in profiling, e.g.
   7 ;;;; total system consing, time spent in a profiled function, and
   8 ;;;; bytes consed in a profiled function are all examples of such
   9 ;;;; quantities. The name is an abbreviation for "Profiling COUNTER".
  10
  11 ;;; This stuff is implemented in the SB!PROFILE package because the
  12 ;;; profiling code is currently the only code which wants to poke
  13 ;;; around in the implementation details. This needs to be done on the
  14 ;;; host for type information.
  15
  16 (in-package "SB!PROFILE")
  17
  18 (def!struct (pcounter (:copier nil))
  19   (integer 0 :type unsigned-byte)
  20   (fixnum 0 :type (and fixnum unsigned-byte)))
  21