src/code/purify.lisp

   1 ;;;; This software is part of the SBCL system. See the README file for
   2 ;;;; more information.
   3 ;;;;
   4 ;;;; This software is derived from the CMU CL system, which was
   5 ;;;; written at Carnegie Mellon University and released into the
   6 ;;;; public domain. The software is in the public domain and is
   7 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
   8 ;;;; files for more information.
   9
  10 (in-package "SB!KERNEL")
  11
  12 (define-alien-routine ("purify" %purify) void
  13   (static-roots unsigned-long)
  14   (read-only-roots unsigned-long))
  15
  16 (defun purify (&key root-structures environment-name)
  17   "This function optimizes garbage collection by moving all currently live
  18    objects into non-collected storage. ROOT-STRUCTURES is an optional list of
  19    objects which should be copied first to maximize locality.
  20
  21    DEFSTRUCT structures defined with the (:PURE T) option are moved into
  22    read-only storage, further reducing GC cost. List and vector slots of pure
  23    structures are also moved into read-only storage.
  24
  25    ENVIRONMENT-NAME is unused.
  26
  27    This function is a no-op on platforms using the generational garbage
  28    collector (x86, x86-64, ppc, arm, arm64)."
  29   (declare (ignore environment-name))
  30   #!+gencgc
  31   (declare (ignore root-structures))
  32   #!-gencgc
  33   (%purify (get-lisp-obj-address root-structures)
  34            (get-lisp-obj-address nil)))