+;;;; support for threads needed at cross-compile time
+
+;;;; This software is part of the SBCL system. See the README file for
+;;;; more information.
+;;;;
+;;;; This software is derived from the CMU CL system, which was
+;;;; written at Carnegie Mellon University and released into the
+;;;; public domain. The software is in the public domain and is
+;;;; provided with absolutely no warranty. See the COPYING and CREDITS
+;;;; files for more information.
+
(in-package "SB!THREAD")
-(defvar *session-lock*)
+(def!struct mutex
+ #!+sb-doc
+ "Mutex type."
+ (name nil :type (or null simple-string))
+ (%owner nil :type (or null thread))
+ #!+(and (not sb-lutex) sb-thread)
+ (state 0 :type fixnum)
+ #!+(and sb-lutex sb-thread)
+ (lutex (make-lutex)))
+
+;;; FIXME: We probably want to rename the accessor MUTEX-OWNER.
+(defun mutex-value (mutex)
+ "Current owner of the mutex, NIL if the mutex is free."
+ (mutex-%owner mutex))
+
+(defsetf mutex-value set-mutex-value)
+
+(declaim (inline set-mutex-value))
+(defun set-mutex-value (mutex value)
+ (declare (ignore mutex value))
+ (error "~S is no longer supported." '(setf mutex-value)))
+
+(define-compiler-macro set-mutex-value (&whole form mutex value)
+ (declare (ignore mutex value))
+ (warn "~S is no longer supported, and will signal an error at runtime."
+ '(setf mutex-value))
+ form)
+
+(def!struct spinlock
+ #!+sb-doc
+ "Spinlock type."
+ (name nil :type (or null simple-string))
+ (value nil))
+
+(sb!xc:defmacro with-mutex ((mutex &key (value '*current-thread*) (wait-p t))
+ &body body)
+ #!+sb-doc
+ "Acquire MUTEX for the dynamic scope of BODY, setting it to
+NEW-VALUE or some suitable default value if NIL. If WAIT-P is non-NIL
+and the mutex is in use, sleep until it is available"
+ `(dx-flet ((with-mutex-thunk () ,@body))
+ (call-with-mutex
+ #'with-mutex-thunk
+ ,mutex
+ ,value
+ ,wait-p)))
+
+(sb!xc:defmacro with-system-mutex ((mutex &key without-gcing allow-with-interrupts) &body body)
+ `(dx-flet ((with-system-mutex-thunk () ,@body))
+ (,(cond (without-gcing
+ 'call-with-system-mutex/without-gcing)
+ (allow-with-interrupts
+ 'call-with-system-mutex/allow-with-interrupts)
+ (t
+ 'call-with-system-mutex))
+ #'with-system-mutex-thunk
+ ,mutex)))
+
+(sb!xc:defmacro with-system-spinlock ((spinlock &key) &body body)
+ `(dx-flet ((with-system-spinlock-thunk () ,@body))
+ (call-with-system-spinlock
+ #'with-system-spinlock-thunk
+ ,spinlock)))
(sb!xc:defmacro with-recursive-lock ((mutex) &body body)
- #!+sb-thread
- (with-unique-names (cfp)
- `(let ((,cfp (sb!kernel:current-fp)))
- (unless (and (mutex-value ,mutex)
- (sb!vm:control-stack-pointer-valid-p
- (sb!sys:int-sap
- (sb!kernel:get-lisp-obj-address (mutex-value ,mutex)))))
- ;; this punning with MAKE-LISP-OBJ depends for its safety on
- ;; the frame pointer being a lispobj-aligned integer. While
- ;; it is, then MAKE-LISP-OBJ will always return a FIXNUM, so
- ;; we're safe to do that. Should this ever change, this
- ;; MAKE-LISP-OBJ could return something that looks like a
- ;; pointer, but pointing into neverneverland, which will
- ;; confuse GC completely. -- CSR, 2003-06-03
- (get-mutex ,mutex (sb!kernel:make-lisp-obj (sb!sys:sap-int ,cfp))))
- (unwind-protect
- (progn ,@body)
- (when (sb!sys:sap= (sb!sys:int-sap
- (sb!kernel:get-lisp-obj-address
- (mutex-value ,mutex)))
- ,cfp)
- (release-mutex ,mutex)))))
- #!-sb-thread
- `(progn ,@body))
+ #!+sb-doc
+ "Acquires MUTEX for the dynamic scope of BODY. Within that scope
+further recursive lock attempts for the same mutex succeed. It is
+allowed to mix WITH-MUTEX and WITH-RECURSIVE-LOCK for the same mutex
+provided the default value is used for the mutex."
+ `(dx-flet ((with-recursive-lock-thunk () ,@body))
+ (call-with-recursive-lock
+ #'with-recursive-lock-thunk
+ ,mutex)))
-#!+sb-thread
-(defun get-foreground ()
- (when (not (eql (mutex-value *session-lock*) (current-thread-id)))
- (get-mutex *session-lock*))
- (sb!sys:enable-interrupt :sigint #'sb!unix::sigint-handler)
- t)
+(sb!xc:defmacro with-recursive-spinlock ((spinlock) &body body)
+ `(dx-flet ((with-recursive-spinlock-thunk () ,@body))
+ (call-with-recursive-spinlock
+ #'with-recursive-spinlock-thunk
+ ,spinlock)))
+
+(sb!xc:defmacro with-recursive-system-spinlock ((spinlock
+ &key without-gcing)
+ &body body)
+ `(dx-flet ((with-recursive-system-spinlock-thunk () ,@body))
+ (,(cond (without-gcing
+ 'call-with-recursive-system-spinlock/without-gcing)
+ (t
+ 'call-with-recursive-system-spinlock))
+ #'with-recursive-system-spinlock-thunk
+ ,spinlock)))
+
+(sb!xc:defmacro with-spinlock ((spinlock) &body body)
+ `(dx-flet ((with-spinlock-thunk () ,@body))
+ (call-with-spinlock
+ #'with-spinlock-thunk
+ ,spinlock)))
+
+;;; KLUDGE: this separate implementation for (NOT SB-THREAD) is not
+;;; strictly necessary; GET-MUTEX and RELEASE-MUTEX are implemented.
+;;; However, there would be a (possibly slight) performance hit in
+;;; using them.
#!-sb-thread
-(defun get-foreground () t)
+(progn
+ (macrolet ((def (name &optional variant)
+ `(defun ,(if variant (symbolicate name "/" variant) name) (function lock)
+ (declare (ignore lock) (function function))
+ ,(ecase variant
+ (:without-gcing
+ `(without-gcing (funcall function)))
+ (:allow-with-interrupts
+ `(without-interrupts (allow-with-interrupts (funcall function))))
+ ((nil)
+ `(without-interrupts (funcall function)))))))
+ (def call-with-system-mutex)
+ (def call-with-system-mutex :without-gcing)
+ (def call-with-system-mutex :allow-with-interrupts)
+ (def call-with-system-spinlock)
+ (def call-with-recursive-system-spinlock)
+ (def call-with-recursive-system-spinlock :without-gcing))
+
+ (defun call-with-mutex (function mutex value waitp)
+ (declare (ignore mutex value waitp)
+ (function function))
+ (funcall function))
+
+ (defun call-with-recursive-lock (function mutex)
+ (declare (ignore mutex) (function function))
+ (funcall function))
+
+ (defun call-with-spinlock (function spinlock)
+ (declare (ignore spinlock) (function function))
+ (funcall function))
+
+ (defun call-with-recursive-spinlock (function spinlock)
+ (declare (ignore spinlock) (function function))
+ (funcall function)))
#!+sb-thread
-(defun release-foreground ()
- (sb!sys:enable-interrupt :sigint :ignore)
- (release-mutex *session-lock*)
- t)
-#!-sb-thread
-(defun release-foreground () t)
+;;; KLUDGE: These need to use DX-LET, because the cleanup form that
+;;; closes over GOT-IT causes a value-cell to be allocated for it --
+;;; and we prefer that to go on the stack since it can.
+(progn
+ (macrolet ((def (name &optional variant)
+ `(defun ,(if variant (symbolicate name "/" variant) name) (function mutex)
+ (declare (function function))
+ (flet ((%call-with-system-mutex ()
+ (dx-let (got-it)
+ (unwind-protect
+ (when (setf got-it (get-mutex mutex))
+ (funcall function))
+ (when got-it
+ (release-mutex mutex))))))
+ (declare (inline %call-with-system-mutex))
+ ,(ecase variant
+ (:without-gcing
+ `(without-gcing (%call-with-system-mutex)))
+ (:allow-with-interrupts
+ `(without-interrupts (allow-with-interrupts (%call-with-system-mutex))))
+ ((nil)
+ `(without-interrupts (%call-with-system-mutex))))))))
+ (def call-with-system-mutex)
+ (def call-with-system-mutex :without-gcing)
+ (def call-with-system-mutex :allow-with-interrupts))
+
+ (defun call-with-system-spinlock (function spinlock)
+ (declare (function function))
+ (without-interrupts
+ (dx-let (got-it)
+ (unwind-protect
+ (when (setf got-it (get-spinlock spinlock))
+ (funcall function))
+ (when got-it
+ (release-spinlock spinlock))))))
+
+ (macrolet ((def (name &optional variant)
+ `(defun ,(if variant (symbolicate name "/" variant) name) (function spinlock)
+ (declare (function function))
+ (flet ((%call-with-system-spinlock ()
+ (dx-let ((inner-lock-p (eq *current-thread* (spinlock-value spinlock)))
+ (got-it nil))
+ (unwind-protect
+ (when (or inner-lock-p (setf got-it (get-spinlock spinlock)))
+ (funcall function))
+ (when got-it
+ (release-spinlock spinlock))))))
+ (declare (inline %call-with-system-spinlock))
+ ,(ecase variant
+ (:without-gcing
+ `(without-gcing (%call-with-system-spinlock)))
+ ((nil)
+ `(without-interrupts (%call-with-system-spinlock))))))))
+ (def call-with-recursive-system-spinlock)
+ (def call-with-recursive-system-spinlock :without-gcing))
+
+ (defun call-with-spinlock (function spinlock)
+ (declare (function function))
+ (dx-let ((got-it nil))
+ (without-interrupts
+ (unwind-protect
+ (when (setf got-it (allow-with-interrupts
+ (get-spinlock spinlock)))
+ (with-local-interrupts (funcall function)))
+ (when got-it
+ (release-spinlock spinlock))))))
+
+ (defun call-with-mutex (function mutex value waitp)
+ (declare (function function))
+ (dx-let ((got-it nil))
+ (without-interrupts
+ (unwind-protect
+ (when (setq got-it (allow-with-interrupts
+ (get-mutex mutex value waitp)))
+ (with-local-interrupts (funcall function)))
+ (when got-it
+ (release-mutex mutex))))))
+
+ (defun call-with-recursive-lock (function mutex)
+ (declare (function function))
+ (dx-let ((inner-lock-p (eq (mutex-%owner mutex) *current-thread*))
+ (got-it nil))
+ (without-interrupts
+ (unwind-protect
+ (when (or inner-lock-p (setf got-it (allow-with-interrupts
+ (get-mutex mutex))))
+ (with-local-interrupts (funcall function)))
+ (when got-it
+ (release-mutex mutex))))))
+
+
+
+ (defun call-with-recursive-spinlock (function spinlock)
+ (declare (function function))
+ (dx-let ((inner-lock-p (eq (spinlock-value spinlock) *current-thread*))
+ (got-it nil))
+ (without-interrupts
+ (unwind-protect
+ (when (or inner-lock-p (setf got-it (allow-with-interrupts
+ (get-spinlock spinlock))))
+ (with-local-interrupts (funcall function)))
+ (when got-it
+ (release-spinlock spinlock)))))))