1.1.13: will be tagged as "sbcl-1.1.13"
[sbcl.git] / src / code / thread.lisp
index 1984470..3d1ecd4 100644 (file)
-(in-package :sb!thread)
-
-(sb!xc:defmacro with-recursive-lock ((mutex) &body body)
-  #!+sb-thread
-  (let ((cfp (gensym "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))
+;;;; 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")
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (sb!xc:proclaim '(sb!ext:always-bound *current-thread*)))
+
+(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)
+  (%ephemeral-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 (foreign-thread
+             (:include thread)
+             (:conc-name "THREAD-"))
+  #!+sb-doc
+  "Type of native threads which are attached to the runtime as Lisp threads
+temporarily.")
+
+#!+(and sb-safepoint-strictly (not win32))
+(def!struct (signal-handling-thread
+             (:include foreign-thread)
+             (:conc-name "THREAD-"))
+  #!+sb-doc
+  "Asynchronous signal handling thread."
+  (signal-number nil :type integer))
+
+(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 "1.0.53.11" 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-spinlock 'with-mutex)
+  `(with-mutex (,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 (progn
+                       (barrier (:read))
+                       (thread-waiting-for ,thread))))
+         (flet ((exec () ,@body))
+           (if ,prev
+               (,without
+                (unwind-protect
+                     (progn
+                       (setf (thread-waiting-for ,thread) nil)
+                       (barrier (:write))
+                       (,with (exec)))
+                  ;; If we were waiting on a waitqueue, this becomes a bogus
+                  ;; wakeup.
+                  (when (mutex-p ,prev)
+                    (setf (thread-waiting-for ,thread) ,prev)
+                    (barrier (:write)))))
+               (exec)))))))
+
+(sb!xc:defmacro with-mutex ((mutex &key (wait-p t) timeout value)
+                            &body body)
+  #!+sb-doc
+  "Acquire MUTEX for the dynamic scope of BODY. If WAIT-P is true (the default),
+and the MUTEX is not immediately available, sleep until it is available.
+
+If TIMEOUT is given, it specifies a relative timeout, in seconds, on how long
+the system should try to acquire the lock in the contested case.
+
+If the mutex isn't acquired succesfully due to either WAIT-P or TIMEOUT, the
+body is not executed, and WITH-MUTEX returns NIL.
+
+Otherwise body is executed with the mutex held by current thread, and
+WITH-MUTEX returns the values of BODY.
+
+Historically WITH-MUTEX also accepted a VALUE argument, which when provided
+was used as the new owner of the mutex instead of the current thread. This is
+no longer supported: if VALUE is provided, it must be either NIL or the
+current thread."
+  `(dx-flet ((with-mutex-thunk () ,@body))
+     (call-with-mutex
+      #'with-mutex-thunk
+      ,mutex
+      ,value
+      ,wait-p
+      ,timeout)))
+
+(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 &key (wait-p t) timeout) &body body)
+  #!+sb-doc
+  "Acquire MUTEX for the dynamic scope of BODY.
+
+If WAIT-P is true (the default), and the MUTEX is not immediately available or
+held by the current thread, sleep until it is available.
+
+If TIMEOUT is given, it specifies a relative timeout, in seconds, on how long
+the system should try to acquire the lock in the contested case.
+
+If the mutex isn't acquired succesfully due to either WAIT-P or TIMEOUT, the
+body is not executed, and WITH-RECURSIVE-LOCK returns NIL.
+
+Otherwise body is executed with the mutex held by current thread, and
+WITH-RECURSIVE-LOCK returns the values of BODY.
+
+Unlike WITH-MUTEX, which signals an error on attempt to re-acquire an already
+held mutex, WITH-RECURSIVE-LOCK allows recursive lock attempts to succeed."
+  `(dx-flet ((with-recursive-lock-thunk () ,@body))
+     (call-with-recursive-lock
+      #'with-recursive-lock-thunk
+      ,mutex
+      ,wait-p
+      ,timeout)))
+
+(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 (grab-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 timeout)
+    (declare (ignore mutex waitp timeout)
+             (function function))
+    (unless (or (null value) (eq *current-thread* value))
+      (error "~S called with non-nil :VALUE that isn't the current thread."
+             'with-mutex))
+    (funcall function))
+
+  (defun call-with-recursive-lock (function mutex waitp timeout)
+    (declare (ignore mutex waitp timeout)
+             (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 mutex))
+    (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 timeout)
+    (declare (function function))
+    (unless (or (null value) (eq *current-thread* value))
+      (error "~S called with non-nil :VALUE that isn't the current thread."
+             'with-mutex))
+    (dx-let ((got-it nil))
+      (without-interrupts
+        (unwind-protect
+             (when (setq got-it (allow-with-interrupts
+                                  (grab-mutex mutex :waitp waitp
+                                                    :timeout timeout)))
+               (with-local-interrupts (funcall function)))
+          (when got-it
+            (release-mutex mutex))))))
+
+  (defun call-with-recursive-lock (function mutex waitp timeout)
+    (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
+                                                   (grab-mutex mutex :waitp waitp
+                                                                     :timeout timeout))))
+               (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)))