src/code/thread.lisp

   1 ;;;; support for threads needed at cross-compile time
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!THREAD")
  13
  14 (def!type thread-name ()
  15   'simple-string)
  16
  17 (def!struct (thread (:constructor %make-thread))
  18   #!+sb-doc
  19   "Thread type. Do not rely on threads being structs as it may change
  20 in future versions."
  21   (name          nil :type (or thread-name null))
  22   (%alive-p      nil :type boolean)
  23   (os-thread     nil :type (or integer null))
  24   (interruptions nil :type list)
  25   (result        nil :type list)
  26   (interruptions-lock
  27    (make-mutex :name "thread interruptions lock")
  28    :type mutex)
  29   (result-lock
  30    (make-mutex :name "thread result lock")
  31    :type mutex))
  32
  33 (def!struct mutex
  34   #!+sb-doc
  35   "Mutex type."
  36   (name   nil :type (or null thread-name))
  37   (%owner nil :type (or null thread))
  38   #!+(and (not sb-lutex) sb-thread)
  39   (state    0 :type fixnum)
  40   #!+(and sb-lutex sb-thread)
  41   (lutex (make-lutex)))
  42
  43 (defun mutex-value (mutex)
  44   "Current owner of the mutex, NIL if the mutex is free. May return a
  45 stale value, use MUTEX-OWNER instead."
  46   (mutex-%owner mutex))
  47
  48 (defun holding-mutex-p (mutex)
  49   "Test whether the current thread is holding MUTEX."
  50   ;; This is about the only use for which a stale value of owner is
  51   ;; sufficient.
  52   (eq sb!thread:*current-thread* (mutex-%owner mutex)))
  53
  54 (defsetf mutex-value set-mutex-value)
  55
  56 (declaim (inline set-mutex-value))
  57 (defun set-mutex-value (mutex value)
  58   (declare (ignore mutex value))
  59   (error "~S is no longer supported." '(setf mutex-value)))
  60
  61 (define-compiler-macro set-mutex-value (&whole form mutex value)
  62   (declare (ignore mutex value))
  63   (warn "~S is no longer supported, and will signal an error at runtime."
  64         '(setf mutex-value))
  65   form)
  66
  67 (def!struct spinlock
  68   #!+sb-doc
  69   "Spinlock type."
  70   (name  nil :type (or null thread-name))
  71   (value nil))
  72
  73 (sb!xc:defmacro with-mutex ((mutex &key (value '*current-thread*) (wait-p t))
  74                             &body body)
  75   #!+sb-doc
  76   "Acquire MUTEX for the dynamic scope of BODY, setting it to VALUE or
  77 some suitable default value if NIL.  If WAIT-P is non-NIL and the mutex
  78 is in use, sleep until it is available"
  79   `(dx-flet ((with-mutex-thunk () ,@body))
  80      (call-with-mutex
  81       #'with-mutex-thunk
  82       ,mutex
  83       ,value
  84       ,wait-p)))
  85
  86 (sb!xc:defmacro with-system-mutex ((mutex
  87                                     &key without-gcing allow-with-interrupts)
  88                                    &body body)
  89   `(dx-flet ((with-system-mutex-thunk () ,@body))
  90      (,(cond (without-gcing
  91                'call-with-system-mutex/without-gcing)
  92              (allow-with-interrupts
  93               'call-with-system-mutex/allow-with-interrupts)
  94              (t
  95               'call-with-system-mutex))
  96        #'with-system-mutex-thunk
  97        ,mutex)))
  98
  99 (sb!xc:defmacro with-system-spinlock ((spinlock &key) &body body)
 100   `(dx-flet ((with-system-spinlock-thunk () ,@body))
 101      (call-with-system-spinlock
 102        #'with-system-spinlock-thunk
 103        ,spinlock)))
 104
 105 (sb!xc:defmacro with-recursive-lock ((mutex) &body body)
 106   #!+sb-doc
 107   "Acquires MUTEX for the dynamic scope of BODY. Within that scope
 108 further recursive lock attempts for the same mutex succeed. It is
 109 allowed to mix WITH-MUTEX and WITH-RECURSIVE-LOCK for the same mutex
 110 provided the default value is used for the mutex."
 111   `(dx-flet ((with-recursive-lock-thunk () ,@body))
 112      (call-with-recursive-lock
 113       #'with-recursive-lock-thunk
 114       ,mutex)))
 115
 116 (sb!xc:defmacro with-recursive-spinlock ((spinlock) &body body)
 117   `(dx-flet ((with-recursive-spinlock-thunk () ,@body))
 118      (call-with-recursive-spinlock
 119       #'with-recursive-spinlock-thunk
 120       ,spinlock)))
 121
 122 (sb!xc:defmacro with-recursive-system-spinlock ((spinlock
 123                                                  &key without-gcing)
 124                                                 &body body)
 125   `(dx-flet ((with-recursive-system-spinlock-thunk () ,@body))
 126      (,(cond (without-gcing
 127                'call-with-recursive-system-spinlock/without-gcing)
 128              (t
 129               'call-with-recursive-system-spinlock))
 130        #'with-recursive-system-spinlock-thunk
 131        ,spinlock)))
 132
 133 (sb!xc:defmacro with-spinlock ((spinlock) &body body)
 134   `(dx-flet ((with-spinlock-thunk () ,@body))
 135      (call-with-spinlock
 136       #'with-spinlock-thunk
 137       ,spinlock)))
 138
 139 (macrolet ((def (name &optional variant)
 140              `(defun ,(if variant (symbolicate name "/" variant) name)
 141                   (function mutex)
 142                 (declare (function function))
 143                 (flet ((%call-with-system-mutex ()
 144                          (dx-let (got-it)
 145                            (unwind-protect
 146                                 (when (setf got-it (get-mutex mutex))
 147                                   (funcall function))
 148                              (when got-it
 149                                (release-mutex mutex))))))
 150                   (declare (inline %call-with-system-mutex))
 151                   ,(ecase variant
 152                      (:without-gcing
 153                        `(without-gcing (%call-with-system-mutex)))
 154                      (:allow-with-interrupts
 155                        `(without-interrupts
 156                           (allow-with-interrupts (%call-with-system-mutex))))
 157                      ((nil)
 158                       `(without-interrupts (%call-with-system-mutex))))))))
 159   (def call-with-system-mutex)
 160   (def call-with-system-mutex :without-gcing)
 161   (def call-with-system-mutex :allow-with-interrupts))
 162
 163 #!-sb-thread
 164 (progn
 165   (macrolet ((def (name &optional variant)
 166                `(defun ,(if variant (symbolicate name "/" variant) name)
 167                     (function lock)
 168                   (declare (ignore lock) (function function))
 169                   ,(ecase variant
 170                     (:without-gcing
 171                       `(without-gcing (funcall function)))
 172                     (:allow-with-interrupts
 173                       `(without-interrupts
 174                          (allow-with-interrupts (funcall function))))
 175                     ((nil)
 176                       `(without-interrupts (funcall function)))))))
 177     (def call-with-system-spinlock)
 178     (def call-with-recursive-system-spinlock)
 179     (def call-with-recursive-system-spinlock :without-gcing))
 180
 181   (defun call-with-mutex (function mutex value waitp)
 182     (declare (ignore mutex value waitp)
 183              (function function))
 184     (funcall function))
 185
 186   (defun call-with-recursive-lock (function mutex)
 187     (declare (ignore mutex) (function function))
 188     (funcall function))
 189
 190   (defun call-with-spinlock (function spinlock)
 191     (declare (ignore spinlock) (function function))
 192     (funcall function))
 193
 194   (defun call-with-recursive-spinlock (function spinlock)
 195     (declare (ignore spinlock) (function function))
 196     (funcall function)))
 197
 198 #!+sb-thread
 199 ;;; KLUDGE: These need to use DX-LET, because the cleanup form that
 200 ;;; closes over GOT-IT causes a value-cell to be allocated for it --
 201 ;;; and we prefer that to go on the stack since it can.
 202 (progn
 203   (defun call-with-system-spinlock (function spinlock)
 204     (declare (function function))
 205     (without-interrupts
 206       (dx-let (got-it)
 207         (unwind-protect
 208              (when (setf got-it (get-spinlock spinlock))
 209                (funcall function))
 210           (when got-it
 211             (release-spinlock spinlock))))))
 212
 213   (macrolet ((def (name &optional variant)
 214                `(defun ,(if variant (symbolicate name "/" variant) name)
 215                     (function spinlock)
 216                   (declare (function function))
 217                   (flet ((%call-with-system-spinlock ()
 218                            (dx-let ((inner-lock-p
 219                                      (eq *current-thread*
 220                                          (spinlock-value spinlock)))
 221                                     (got-it nil))
 222                              (unwind-protect
 223                                   (when (or inner-lock-p
 224                                             (setf got-it
 225                                                   (get-spinlock spinlock)))
 226                                     (funcall function))
 227                                (when got-it
 228                                  (release-spinlock spinlock))))))
 229                     (declare (inline %call-with-system-spinlock))
 230                     ,(ecase variant
 231                       (:without-gcing
 232                         `(without-gcing (%call-with-system-spinlock)))
 233                       ((nil)
 234                         `(without-interrupts (%call-with-system-spinlock))))))))
 235     (def call-with-recursive-system-spinlock)
 236     (def call-with-recursive-system-spinlock :without-gcing))
 237
 238   (defun call-with-spinlock (function spinlock)
 239     (declare (function function))
 240     (dx-let ((got-it nil))
 241       (without-interrupts
 242         (unwind-protect
 243              (when (setf got-it (allow-with-interrupts
 244                                  (get-spinlock spinlock)))
 245                (with-local-interrupts (funcall function)))
 246           (when got-it
 247             (release-spinlock spinlock))))))
 248
 249   (defun call-with-mutex (function mutex value waitp)
 250     (declare (function function))
 251     (dx-let ((got-it nil))
 252       (without-interrupts
 253         (unwind-protect
 254              (when (setq got-it (allow-with-interrupts
 255                                  (get-mutex mutex value waitp)))
 256                (with-local-interrupts (funcall function)))
 257           (when got-it
 258             (release-mutex mutex))))))
 259
 260   (defun call-with-recursive-lock (function mutex)
 261     (declare (function function))
 262     (dx-let ((inner-lock-p (eq (mutex-%owner mutex) *current-thread*))
 263              (got-it nil))
 264       (without-interrupts
 265         (unwind-protect
 266              (when (or inner-lock-p (setf got-it (allow-with-interrupts
 267                                                   (get-mutex mutex))))
 268                (with-local-interrupts (funcall function)))
 269           (when got-it
 270             (release-mutex mutex))))))
 271
 272   (defun call-with-recursive-spinlock (function spinlock)
 273     (declare (function function))
 274     (dx-let ((inner-lock-p (eq (spinlock-value spinlock) *current-thread*))
 275           (got-it nil))
 276       (without-interrupts
 277         (unwind-protect
 278              (when (or inner-lock-p (setf got-it (allow-with-interrupts
 279                                                   (get-spinlock spinlock))))
 280                (with-local-interrupts (funcall function)))
 281           (when got-it
 282             (release-spinlock spinlock)))))))