+;;;; 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!type thread-name ()
+ 'simple-string)
+
+(def!struct (thread (:constructor %make-thread))
+ #!+sb-doc
+ "Thread type. Do not rely on threads being structs as it may change
+in future versions."
+ (name nil :type (or thread-name null))
+ (%alive-p nil :type boolean)
+ (os-thread nil :type (or integer null))
+ (interruptions nil :type list)
+ (result nil :type list)
+ (interruptions-lock
+ (make-mutex :name "thread interruptions lock")
+ :type mutex)
+ (result-lock
+ (make-mutex :name "thread result lock")
+ :type mutex)
+ waiting-for)
+
+(def!struct mutex
+ #!+sb-doc
+ "Mutex type."
+ (name nil :type (or null thread-name))
+ (%owner nil :type (or null thread))
+ #!+(and sb-thread sb-futex)
+ (state 0 :type fixnum))
+
+(defun mutex-value (mutex)
+ "Current owner of the mutex, NIL if the mutex is free. May return a
+stale value, use MUTEX-OWNER instead."
+ (mutex-%owner mutex))
+
+(defun holding-mutex-p (mutex)
+ "Test whether the current thread is holding MUTEX."
+ ;; This is about the only use for which a stale value of owner is
+ ;; sufficient.
+ (eq sb!thread:*current-thread* (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)
+
+;;; SPINLOCK no longer exists as a type -- provided for backwards compatibility.
+
+(deftype spinlock ()
+ "Spinlock type."
+ (deprecation-warning :early "1.0.53.11" 'spinlock 'mutex)
+ 'mutex)
+
+(define-deprecated-function :early "1.0.53.11" make-spinlock make-mutex (&key name)
+ (make-mutex :name name))
+
+(define-deprecated-function :early "1.0.5.x" spinlock-name mutex-name (lock)
+ (mutex-name lock))
+
+(define-deprecated-function :early "1.0.53.11" (setf spinlock-name) (setf mutex-name) (name lock)
+ (setf (mutex-name lock) name))
+
+(define-deprecated-function :early "1.0.53.11" spinlock-value mutex-owner (lock)
+ (mutex-owner lock))
+
+(define-deprecated-function :early "1.0.53.11" get-spinlock grab-mutex (lock)
+ (grab-mutex lock))
+
+(define-deprecated-function :early "1.0.53.11" release-spinlock release-mutex (lock)
+ (release-mutex lock))
+
+(sb!xc:defmacro with-recursive-spinlock ((lock) &body body)
+ (deprecation-warning :early "1.0.53.11" 'with-recursive-spinlock 'with-recursive-lock)
+ `(with-recursive-lock (,lock)
+ ,@body))
+
+(sb!xc:defmacro with-spinlock ((lock) &body body)
+ (deprecation-warning :early "1.0.53.11" 'with-recursive-spinlock 'with-mutex)
+ `(with-lock (,lock)
+ ,@body))
+
+(sb!xc:defmacro without-thread-waiting-for ((&key already-without-interrupts) &body body)
+ (with-unique-names (thread prev)
+ (let ((without (if already-without-interrupts
+ 'progn
+ 'without-interrupts))
+ (with (if already-without-interrupts
+ 'progn
+ 'with-local-interrupts)))
+ `(let* ((,thread *current-thread*)
+ (,prev (thread-waiting-for ,thread)))
+ (flet ((exec () ,@body))
+ (if ,prev
+ (,without
+ (unwind-protect
+ (progn
+ (setf (thread-waiting-for ,thread) nil)
+ (,with (exec)))
+ (setf (thread-waiting-for ,thread) ,prev)))
+ (exec)))))))
+
+(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 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-recursive-lock ((mutex) &body body)
- #!+sb-thread
- (with-unique-names (cfp)
- `(let ((,cfp (ash (sb!sys:sap-int (sb!vm::current-fp) ) -2)))
- (unless (and (mutex-value ,mutex)
- (SB!DI::control-stack-pointer-valid-p
- (sb!sys:int-sap (ash (mutex-value ,mutex) 2))))
- (get-mutex ,mutex ,cfp))
- (unwind-protect
- (progn ,@body)
- (when (eql (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!xc:defmacro with-recursive-system-lock ((lock
+ &key without-gcing)
+ &body body)
+ `(dx-flet ((with-recursive-system-lock-thunk () ,@body))
+ (,(cond (without-gcing
+ 'call-with-recursive-system-lock/without-gcing)
+ (t
+ 'call-with-recursive-system-lock))
+ #'with-recursive-system-lock-thunk
+ ,lock)))
+
+(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))
-#!+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-thread
-(defun get-foreground () t)
+(progn
+ (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-recursive-system-lock (function lock)
+ (declare (function function) (ignore lock))
+ (without-interrupts
+ (funcall function)))
+
+ (defun call-with-recursive-system-lock/without-gcing (function mutex)
+ (declare (function function) (ignore lock))
+ (without-gcing
+ (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
+ (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))))))
+
+ (macrolet ((def (name &optional variant)
+ `(defun ,(if variant (symbolicate name "/" variant) name)
+ (function lock)
+ (declare (function function))
+ (flet ((%call-with-recursive-system-lock ()
+ (dx-let ((inner-lock-p
+ (eq *current-thread* (mutex-owner lock)))
+ (got-it nil))
+ (unwind-protect
+ (when (or inner-lock-p
+ (setf got-it (grab-mutex lock)))
+ (funcall function))
+ (when got-it
+ (release-mutex lock))))))
+ (declare (inline %call-with-recursive-system-lock))
+ ,(ecase variant
+ (:without-gcing
+ `(without-gcing (%call-with-recursive-system-lock)))
+ ((nil)
+ `(without-interrupts (%call-with-recursive-system-lock))))))))
+ (def call-with-recursive-system-lock)
+ (def call-with-recursive-system-lock :without-gcing)))