src/code/early-thread.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!THREAD")
  11
  12 (eval-when (:compile-toplevel :load-toplevel :execute)
  13   (defvar *current-thread* nil))
  14
  15 (def!type thread-name () 'simple-string)
  16
  17 ;;; THREAD and MUTEX are mutually referential types, and the compiler isn't
  18 ;;; generally intelligent enough to compile out-of-line setters efficiently
  19 ;;; when it has to type-check an unknown, such as MUTEX-%OWNER which is
  20 ;;; (OR NULL THREAD). But this is not a problem for the constructor,
  21 ;;; because %OWNER's default is NIL which statically passes the test.
  22 ;;; #'(SETF %OWNER) is suboptimally compiled, which is irrelevant,
  23 ;;; because it is never called. But you can't use CAS on the slot unless it
  24 ;;; is read/write, which necessarily defines a writer (that we don't want).
  25
  26 (declaim (inline make-mutex)) ;; for possible DX-allocating
  27 (defstruct (mutex
  28              (:constructor make-mutex (&key name)))
  29   #!+sb-doc
  30   "Mutex type."
  31   (name   nil :type (or null thread-name))
  32   (%owner nil :type (or null thread))
  33   #!+(and sb-thread sb-futex)
  34   (state    0 :type fixnum))
  35 (declaim (notinline make-mutex))
  36
  37 (defstruct (thread (:constructor %make-thread))
  38   #!+sb-doc
  39   "Thread type. Do not rely on threads being structs as it may change
  40 in future versions."
  41   (name          nil :type (or thread-name null))
  42   (%alive-p      nil :type boolean)
  43   (%ephemeral-p  nil :type boolean)
  44   #-sb-xc-host
  45   (os-thread     0 :type sb!vm:word)
  46   (interruptions nil :type list)
  47   ;; On succesful execution of the thread's lambda a list of values.
  48   (result 0)
  49   (interruptions-lock
  50    (make-mutex :name "thread interruptions lock")
  51    :type mutex)
  52   (result-lock
  53    (make-mutex :name "thread result lock")
  54    :type mutex)
  55   waiting-for)