(in-package "SB!THREAD")
+;;; Of the WITH-PINNED-OBJECTS in this file, not every single one is
+;;; necessary because threads are only supported with the conservative
+;;; gencgc and numbers on the stack (returned by GET-LISP-OBJ-ADDRESS)
+;;; are treated as references.
+
;;; set the doc here because in early-thread FDOCUMENTATION is not
;;; available, yet
#!+sb-doc
-(setf (sb!kernel:fdocumentation '*current-thread* 'variable)
+(setf (fdocumentation '*current-thread* 'variable)
"Bound in each thread to the thread itself.")
(defstruct (thread (:constructor %make-thread))
"Thread type. Do not rely on threads being structs as it may change
in future versions."
name
- %sap)
+ %alive-p
+ os-thread
+ interruptions
+ (interruptions-lock (make-mutex :name "thread interruptions lock"))
+ result
+ (result-lock (make-mutex :name "thread result lock")))
#!+sb-doc
-(setf (sb!kernel:fdocumentation 'thread-name 'function)
+(setf (fdocumentation 'thread-name 'function)
"The name of the thread. Setfable.")
(def!method print-object ((thread thread) stream)
))
thread)
-(defun thread-state (thread)
- (let ((state
- (sb!sys:sap-int
- (sb!sys:sap-ref-sap (thread-%sap thread)
- (* sb!vm::thread-state-slot
- sb!vm::n-word-bytes)))))
- (ecase state
- (#.(sb!vm:fixnumize 0) :starting)
- (#.(sb!vm:fixnumize 1) :running)
- (#.(sb!vm:fixnumize 2) :suspended)
- (#.(sb!vm:fixnumize 3) :dead))))
-
(defun thread-alive-p (thread)
#!+sb-doc
"Check if THREAD is running."
- (not (eq :dead (thread-state thread))))
+ (thread-%alive-p thread))
;; A thread is eligible for gc iff it has finished and there are no
;; more references to it. This list is supposed to keep a reference to
(defvar *all-threads* ())
(defvar *all-threads-lock* (make-mutex :name "all threads lock"))
+(defmacro with-all-threads-lock (&body body)
+ #!-sb-thread
+ `(locally ,@body)
+ #!+sb-thread
+ `(without-interrupts
+ (with-mutex (*all-threads-lock*)
+ ,@body)))
+
(defun list-all-threads ()
#!+sb-doc
"Return a list of the live threads."
- (with-mutex (*all-threads-lock*)
+ (with-all-threads-lock
(copy-list *all-threads*)))
(declaim (inline current-thread-sap))
(declaim (inline current-thread-sap-id))
(defun current-thread-sap-id ()
- (sb!sys:sap-int
+ (sap-int
(sb!vm::current-thread-offset-sap sb!vm::thread-os-thread-slot)))
(defun init-initial-thread ()
+ (/show0 "Entering INIT-INITIAL-THREAD")
(let ((initial-thread (%make-thread :name "initial thread"
- :%sap (current-thread-sap))))
+ :%alive-p t
+ :os-thread (current-thread-sap-id))))
(setq *current-thread* initial-thread)
;; Either *all-threads* is empty or it contains exactly one thread
;; in case we are in reinit since saving core with multiple
#!+sb-thread
(progn
+ ;; FIXME it would be good to define what a thread id is or isn't
+ ;; (our current assumption is that it's a fixnum). It so happens
+ ;; that on Linux it's a pid, but it might not be on posix thread
+ ;; implementations.
(define-alien-routine ("create_thread" %create-thread)
- system-area-pointer
- (lisp-fun-address unsigned-long))
+ unsigned-long (lisp-fun-address unsigned-long))
+
+ (define-alien-routine "signal_interrupt_thread"
+ integer (os-thread unsigned-long))
+
+ (define-alien-routine "block_deferrable_signals"
+ void)
+
+ #!+sb-lutex
+ (progn
+ (declaim (inline %lutex-init %lutex-wait %lutex-wake
+ %lutex-lock %lutex-unlock))
+
+ (sb!alien:define-alien-routine ("lutex_init" %lutex-init)
+ int (lutex unsigned-long))
+
+ (sb!alien:define-alien-routine ("lutex_wait" %lutex-wait)
+ int (queue-lutex unsigned-long) (mutex-lutex unsigned-long))
+
+ (sb!alien:define-alien-routine ("lutex_wake" %lutex-wake)
+ int (lutex unsigned-long) (n int))
- (define-alien-routine "block_blockable_signals"
- void)
+ (sb!alien:define-alien-routine ("lutex_lock" %lutex-lock)
+ int (lutex unsigned-long))
- (define-alien-routine reap-dead-thread void
- (thread-sap system-area-pointer))
+ (sb!alien:define-alien-routine ("lutex_trylock" %lutex-trylock)
+ int (lutex unsigned-long))
- (declaim (inline futex-wait futex-wake))
+ (sb!alien:define-alien-routine ("lutex_unlock" %lutex-unlock)
+ int (lutex unsigned-long))
- (sb!alien:define-alien-routine "futex_wait"
- int (word unsigned-long) (old-value unsigned-long))
+ (sb!alien:define-alien-routine ("lutex_destroy" %lutex-destroy)
+ int (lutex unsigned-long))
- (sb!alien:define-alien-routine "futex_wake"
- int (word unsigned-long) (n unsigned-long)))
+ ;; FIXME: Defining a whole bunch of alien-type machinery just for
+ ;; passing primitive lutex objects directly to foreign functions
+ ;; doesn't seem like fun right now. So instead we just manually
+ ;; pin the lutex, get its address, and let the callee untag it.
+ (defmacro with-lutex-address ((name lutex) &body body)
+ `(let ((,name ,lutex))
+ (with-pinned-objects (,name)
+ (let ((,name (get-lisp-obj-address ,name)))
+ ,@body))))
+
+ (defun make-lutex ()
+ (/show0 "Entering MAKE-LUTEX")
+ ;; Suppress GC until the lutex has been properly registered with
+ ;; the GC.
+ (without-gcing
+ (let ((lutex (sb!vm::%make-lutex)))
+ (/show0 "LUTEX=..")
+ (/hexstr lutex)
+ (with-lutex-address (lutex lutex)
+ (%lutex-init lutex))
+ lutex))))
+
+ #!-sb-lutex
+ (progn
+ (declaim (inline futex-wait futex-wake))
+
+ (sb!alien:define-alien-routine "futex_wait"
+ int (word unsigned-long) (old-value unsigned-long))
+
+ (sb!alien:define-alien-routine "futex_wake"
+ int (word unsigned-long) (n unsigned-long))))
;;; used by debug-int.lisp to access interrupt contexts
-#!-(and sb-fluid sb-thread) (declaim (inline sb!vm::current-thread-offset-sap))
+#!-(or sb-fluid sb-thread) (declaim (inline sb!vm::current-thread-offset-sap))
#!-sb-thread
(defun sb!vm::current-thread-offset-sap (n)
(declare (type (unsigned-byte 27) n))
- (sb!sys:sap-ref-sap (alien-sap (extern-alien "all_threads" (* t)))
+ (sap-ref-sap (alien-sap (extern-alien "all_threads" (* t)))
(* n sb!vm:n-word-bytes)))
-;;;; spinlocks
+#!+sb-thread
+(defun sb!vm::current-thread-offset-sap (n)
+ (declare (type (unsigned-byte 27) n))
+ (sb!vm::current-thread-offset-sap n))
-(defstruct spinlock
- #!+sb-doc
- "Spinlock type."
- (name nil :type (or null simple-string))
- (value 0))
+;;;; spinlocks
+#!+sb-thread
+(define-structure-slot-compare-and-swap
+ compare-and-swap-spinlock-value
+ :structure spinlock
+ :slot value)
(declaim (inline get-spinlock release-spinlock))
-;;; The bare 2 here and below are offsets of the slots in the struct.
-;;; There ought to be some better way to get these numbers
-(defun get-spinlock (spinlock new-value)
+(defun get-spinlock (spinlock)
(declare (optimize (speed 3) (safety 0))
#!-sb-thread
- (ignore spinlock new-value))
+ (ignore spinlock))
;; %instance-set-conditional can test for 0 (which is a fixnum) and
;; store any value
#!+sb-thread
(loop until
- (eql (sb!vm::%instance-set-conditional spinlock 2 0 new-value) 0)))
+ (eql 0 (compare-and-swap-spinlock-value spinlock 0 1)))
+ t)
(defun release-spinlock (spinlock)
(declare (optimize (speed 3) (safety 0))
#!-sb-thread (ignore spinlock))
;; %instance-set-conditional cannot compare arbitrary objects
- ;; meaningfully, so
- ;; (sb!vm::%instance-set-conditional spinlock 2 our-value 0)
+ ;; meaningfully, so (compare-and-swap-spinlock-value our-value 0)
;; does not work for bignum thread ids.
#!+sb-thread
- (sb!vm::%instance-set spinlock 2 0))
-
-(defmacro with-spinlock ((spinlock) &body body)
- (sb!int:with-unique-names (lock)
- `(let ((,lock ,spinlock))
- (get-spinlock ,lock *current-thread*)
- (unwind-protect
- (progn ,@body)
- (release-spinlock ,lock)))))
+ (setf (spinlock-value spinlock) 0)
+ nil)
;;;; mutexes
-(defstruct mutex
- #!+sb-doc
- "Mutex type."
- (name nil :type (or null simple-string))
- (value nil))
-
#!+sb-doc
-(setf (sb!kernel:fdocumentation 'make-mutex 'function)
+(setf (fdocumentation 'make-mutex 'function)
"Create a mutex."
- (sb!kernel:fdocumentation 'mutex-name 'function)
+ (fdocumentation 'mutex-name 'function)
"The name of the mutex. Setfable."
- (sb!kernel:fdocumentation 'mutex-value 'function)
+ (fdocumentation 'mutex-value 'function)
"The value of the mutex. NIL if the mutex is free. Setfable.")
-#!+sb-thread
-(declaim (inline mutex-value-address))
-#!+sb-thread
-(defun mutex-value-address (mutex)
- (declare (optimize (speed 3)))
- (sb!ext:truly-the
- sb!vm:word
- (+ (sb!kernel:get-lisp-obj-address mutex)
- (- (* 3 sb!vm:n-word-bytes) sb!vm:instance-pointer-lowtag))))
-
-(defun get-mutex (mutex &optional new-value (wait-p t))
+#!+(and sb-thread (not sb-lutex))
+(progn
+ (define-structure-slot-addressor mutex-value-address
+ :structure mutex
+ :slot value)
+ (define-structure-slot-compare-and-swap
+ compare-and-swap-mutex-value
+ :structure mutex
+ :slot value))
+
+(defun get-mutex (mutex &optional (new-value *current-thread*) (wait-p t))
#!+sb-doc
"Acquire MUTEX, 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"
+value if NIL. If WAIT-P is non-NIL and the mutex is in use, sleep
+until it is available."
(declare (type mutex mutex) (optimize (speed 3)))
- (unless new-value (setf new-value *current-thread*))
+ (/show0 "Entering GET-MUTEX")
+ (unless new-value
+ (setq new-value *current-thread*))
#!-sb-thread
(let ((old-value (mutex-value mutex)))
(when (and old-value wait-p)
(setf (mutex-value mutex) new-value)
t)
#!+sb-thread
- (let (old)
+ (progn
(when (eql new-value (mutex-value mutex))
(warn "recursive lock attempt ~S~%" mutex)
(format *debug-io* "Thread: ~A~%" *current-thread*)
(sb!debug:backtrace most-positive-fixnum *debug-io*)
(force-output *debug-io*))
- (loop
- (unless
- (setf old (sb!vm::%instance-set-conditional mutex 2 nil new-value))
- (return t))
- (unless wait-p (return nil))
- (futex-wait (mutex-value-address mutex)
- (sb!kernel:get-lisp-obj-address old)))))
+ #!+sb-lutex
+ (when (zerop (with-lutex-address (lutex (mutex-lutex mutex))
+ (if wait-p
+ (%lutex-lock lutex)
+ (%lutex-trylock lutex))))
+ (setf (mutex-value mutex) new-value))
+ #!-sb-lutex
+ (let (old)
+ (loop
+ (unless
+ (setf old
+ (compare-and-swap-mutex-value mutex nil new-value))
+ (return t))
+ (unless wait-p (return nil))
+ (with-pinned-objects (mutex old)
+ (futex-wait (mutex-value-address mutex)
+ (get-lisp-obj-address old)))))))
(defun release-mutex (mutex)
#!+sb-doc
"Release MUTEX by setting it to NIL. Wake up threads waiting for
this mutex."
(declare (type mutex mutex))
+ (/show0 "Entering RELEASE-MUTEX")
(setf (mutex-value mutex) nil)
#!+sb-thread
- (futex-wake (mutex-value-address mutex) 1))
+ (progn
+ #!+sb-lutex
+ (with-lutex-address (lutex (mutex-lutex mutex))
+ (%lutex-unlock lutex))
+ #!-sb-lutex
+ (futex-wake (mutex-value-address mutex) 1)))
;;;; waitqueues/condition variables
#!+sb-doc
"Waitqueue type."
(name nil :type (or null simple-string))
+ #!+(and sb-lutex sb-thread)
+ (lutex (make-lutex))
+ #!-sb-lutex
(data nil))
(defun make-waitqueue (&key name)
(%make-waitqueue :name name))
#!+sb-doc
-(setf (sb!kernel:fdocumentation 'waitqueue-name 'function)
+(setf (fdocumentation 'waitqueue-name 'function)
"The name of the waitqueue. Setfable.")
-#!+sb-thread
-(declaim (inline waitqueue-data-address))
-#!+sb-thread
-(defun waitqueue-data-address (waitqueue)
- (declare (optimize (speed 3)))
- (sb!ext:truly-the
- sb!vm:word
- (+ (sb!kernel:get-lisp-obj-address waitqueue)
- (- (* 3 sb!vm:n-word-bytes) sb!vm:instance-pointer-lowtag))))
+#!+(and sb-thread (not sb-lutex))
+(define-structure-slot-addressor waitqueue-data-address
+ :structure waitqueue
+ :slot data)
(defun condition-wait (queue mutex)
#!+sb-doc
#!-sb-thread (error "Not supported in unithread builds.")
#!+sb-thread
(let ((value (mutex-value mutex)))
+ (/show0 "CONDITION-WAITing")
+ #!+sb-lutex
+ (progn
+ (setf (mutex-value mutex) nil)
+ (with-lutex-address (queue-lutex-address (waitqueue-lutex queue))
+ (with-lutex-address (mutex-lutex-address (mutex-lutex mutex))
+ (%lutex-wait queue-lutex-address mutex-lutex-address)))
+ (setf (mutex-value mutex) value))
+ #!-sb-lutex
(unwind-protect
(let ((me *current-thread*))
;; XXX we should do something to ensure that the result of this setf
;; this comment, it will change queue->data, and so
;; futex-wait returns immediately instead of sleeping.
;; Ergo, no lost wakeup
- (futex-wait (waitqueue-data-address queue)
- (sb!kernel:get-lisp-obj-address me)))
+ (with-pinned-objects (queue me)
+ (futex-wait (waitqueue-data-address queue)
+ (get-lisp-obj-address me))))
;; If we are interrupted while waiting, we should do these things
;; before returning. Ideally, in the case of an unhandled signal,
;; we should do them before entering the debugger, but this is
#!-sb-thread (error "Not supported in unithread builds.")
#!+sb-thread
(declare (type (and fixnum (integer 1)) n))
+ (/show0 "Entering CONDITION-NOTIFY")
#!+sb-thread
- (let ((me *current-thread*))
+ (progn
+ #!+sb-lutex
+ (with-lutex-address (lutex (waitqueue-lutex queue))
+ (%lutex-wake lutex n))
;; no problem if >1 thread notifies during the comment in
;; condition-wait: as long as the value in queue-data isn't the
;; waiting thread's id, it matters not what it is
;; XXX we should do something to ensure that the result of this setf
;; is visible to all CPUs
- (setf (waitqueue-data queue) me)
- (futex-wake (waitqueue-data-address queue) n)))
+ #!-sb-lutex
+ (let ((me *current-thread*))
+ (progn
+ (setf (waitqueue-data queue) me)
+ (with-pinned-objects (queue)
+ (futex-wake (waitqueue-data-address queue) n))))))
(defun condition-broadcast (queue)
#!+sb-doc
"Notify all threads waiting on QUEUE."
- (condition-notify queue most-positive-fixnum))
+ (condition-notify queue
+ ;; On a 64-bit platform truncating M-P-F to an int results
+ ;; in -1, which wakes up only one thread.
+ (ldb (byte 29 0)
+ most-positive-fixnum)))
;;;; semaphores
"Create a semaphore with the supplied COUNT."
(%make-semaphore :name name :count count))
-(setf (sb!kernel:fdocumentation 'semaphore-name 'function)
+(setf (fdocumentation 'semaphore-name 'function)
"The name of the semaphore. Setfable.")
(defun wait-on-semaphore (sem)
#!-sb-thread
`(locally ,@body)
#!+sb-thread
- `(sb!sys:without-interrupts
- (with-mutex ((session-lock ,session))
- ,@body)))
+ `(without-interrupts
+ (with-mutex ((session-lock ,session))
+ ,@body)))
(defun new-session ()
(make-session :threads (list *current-thread*)
:interactive-threads (list *current-thread*)))
(defun init-job-control ()
- (setf *session* (new-session)))
+ (/show0 "Entering INIT-JOB-CONTROL")
+ (setf *session* (new-session))
+ (/show0 "Exiting INIT-JOB-CONTROL"))
(defun %delete-thread-from-session (thread session)
(with-session-lock (session)
;;; Remove thread from its session, if it has one.
#!+sb-thread
(defun handle-thread-exit (thread)
- (with-mutex (*all-threads-lock*)
- (setq *all-threads* (delete thread *all-threads*)))
- (when *session*
- (%delete-thread-from-session thread *session*)))
+ (/show0 "HANDLING THREAD EXIT")
+ ;; We're going down, can't handle interrupts sanely anymore.
+ ;; GC remains enabled.
+ (block-deferrable-signals)
+ ;; Lisp-side cleanup
+ (with-all-threads-lock
+ (setf (thread-%alive-p thread) nil)
+ (setf (thread-os-thread thread) nil)
+ (setq *all-threads* (delete thread *all-threads*))
+ (when *session*
+ (%delete-thread-from-session thread *session*)))
+ #!+sb-lutex
+ (without-gcing
+ (/show0 "FREEING MUTEX LUTEX")
+ (with-lutex-address (lutex (mutex-lutex (thread-interruptions-lock thread)))
+ (%lutex-destroy lutex))))
(defun terminate-session ()
#!+sb-doc
#!+sb-thread
(let ((was-foreground t))
(loop
+ (/show0 "Looping in GET-FOREGROUND")
(with-session-lock (*session*)
(let ((int-t (session-interactive-threads *session*)))
(when (eq (car int-t) *current-thread*)
(labels ((thread-repl ()
(sb!unix::unix-setsid)
(let* ((sb!impl::*stdin*
- (sb!sys:make-fd-stream in :input t :buffering :line
- :dual-channel-p t))
+ (make-fd-stream in :input t :buffering :line
+ :dual-channel-p t))
(sb!impl::*stdout*
- (sb!sys:make-fd-stream out :output t :buffering :line
+ (make-fd-stream out :output t :buffering :line
:dual-channel-p t))
(sb!impl::*stderr*
- (sb!sys:make-fd-stream err :output t :buffering :line
+ (make-fd-stream err :output t :buffering :line
:dual-channel-p t))
(sb!impl::*tty*
- (sb!sys:make-fd-stream err :input t :output t
+ (make-fd-stream err :input t :output t
:buffering :line
:dual-channel-p t))
(sb!impl::*descriptor-handlers* nil))
(defun make-thread (function &key name)
#!+sb-doc
"Create a new thread of NAME that runs FUNCTION. When the function
-returns the thread exits."
+returns the thread exits. The return values of FUNCTION are kept
+around and can be retrieved by JOIN-THREAD."
#!-sb-thread (declare (ignore function name))
#!-sb-thread (error "Not supported in unithread builds.")
#!+sb-thread
(let* ((thread (%make-thread :name name))
(setup-sem (make-semaphore :name "Thread setup semaphore"))
(real-function (coerce function 'function))
- (thread-sap
- ;; don't let the child inherit *CURRENT-THREAD* because that
- ;; can prevent gc'ing this thread while the child runs
- (let ((*current-thread* nil))
- (%create-thread
- (sb!kernel:get-lisp-obj-address
- (lambda ()
- ;; in time we'll move some of the binding presently done in C
- ;; here too
- (let ((*current-thread* thread)
- (sb!kernel::*restart-clusters* nil)
- (sb!kernel::*handler-clusters* nil)
- (sb!kernel::*condition-restarts* nil)
- (sb!impl::*descriptor-handlers* nil)) ; serve-event
- (wait-on-semaphore setup-sem)
- ;; can't use handling-end-of-the-world, because that flushes
- ;; output streams, and we don't necessarily have any (or we
- ;; could be sharing them)
- (unwind-protect
- (catch 'sb!impl::toplevel-catcher
- (catch 'sb!impl::%end-of-the-world
- (with-simple-restart
- (terminate-thread
- (format nil
- "~~@<Terminate this thread (~A)~~@:>"
- *current-thread*))
+ (initial-function
+ (lambda ()
+ ;; In time we'll move some of the binding presently done in C
+ ;; here too.
+ ;;
+ ;; KLUDGE: Here we have a magic list of variables that are
+ ;; not thread-safe for one reason or another. As people
+ ;; report problems with the thread safety of certain
+ ;; variables, (e.g. "*print-case* in multiple threads
+ ;; broken", sbcl-devel 2006-07-14), we add a few more
+ ;; bindings here. The Right Thing is probably some variant
+ ;; of Allegro's *cl-default-special-bindings*, as that is at
+ ;; least accessible to users to secure their own libraries.
+ ;; --njf, 2006-07-15
+ (let ((*current-thread* thread)
+ (*restart-clusters* nil)
+ (*handler-clusters* nil)
+ (*condition-restarts* nil)
+ (sb!impl::*step-out* nil)
+ ;; internal printer variables
+ (sb!impl::*previous-case* nil)
+ (sb!impl::*previous-readtable-case* nil)
+ (sb!impl::*merge-sort-temp-vector* (vector)) ; keep these small!
+ (sb!impl::*zap-array-data-temp* (vector)) ;
+ (sb!impl::*internal-symbol-output-fun* nil)
+ (sb!impl::*descriptor-handlers* nil)) ; serve-event
+ (setf (thread-os-thread thread) (current-thread-sap-id))
+ (with-mutex ((thread-result-lock thread))
+ (with-all-threads-lock
+ (push thread *all-threads*))
+ (with-session-lock (*session*)
+ (push thread (session-threads *session*)))
+ (setf (thread-%alive-p thread) t)
+ (signal-semaphore setup-sem)
+ ;; can't use handling-end-of-the-world, because that flushes
+ ;; output streams, and we don't necessarily have any (or we
+ ;; could be sharing them)
+ (catch 'sb!impl::toplevel-catcher
+ (catch 'sb!impl::%end-of-the-world
+ (with-simple-restart
+ (terminate-thread
+ (format nil
+ "~~@<Terminate this thread (~A)~~@:>"
+ *current-thread*))
+ (unwind-protect
+ (progn
;; now that most things have a chance to
;; work properly without messing up other
;; threads, it's time to enable signals
(sb!unix::reset-signal-mask)
- (unwind-protect
- (funcall real-function)
- ;; we're going down, can't handle
- ;; interrupts sanely anymore
- (let ((sb!impl::*gc-inhibit* t))
- (block-blockable-signals)
- ;; and remove what can be the last
- ;; reference to this thread
- (handle-thread-exit thread))))))
- 0))
- (values)))))))
- (when (sb!sys:sap= thread-sap (sb!sys:int-sap 0))
- (error "Can't create a new thread"))
- (setf (thread-%sap thread) thread-sap)
- (with-mutex (*all-threads-lock*)
- (push thread *all-threads*))
- (with-session-lock (*session*)
- (push thread (session-threads *session*)))
- (signal-semaphore setup-sem)
- (sb!impl::finalize thread (lambda () (reap-dead-thread thread-sap)))
- thread))
+ (setf (thread-result thread)
+ (cons t
+ (multiple-value-list
+ (funcall real-function)))))
+ (handle-thread-exit thread)))))))
+ (values))))
+ ;; Keep INITIAL-FUNCTION pinned until the child thread is
+ ;; initialized properly.
+ (with-pinned-objects (initial-function)
+ (let ((os-thread
+ (%create-thread
+ (get-lisp-obj-address initial-function))))
+ (when (zerop os-thread)
+ (error "Can't create a new thread"))
+ (wait-on-semaphore setup-sem)
+ thread))))
+
+(define-condition join-thread-error (error)
+ ((thread :reader join-thread-error-thread :initarg :thread))
+ #!+sb-doc
+ (:documentation "Joining thread failed.")
+ (:report (lambda (c s)
+ (format s "Joining thread failed: thread ~A ~
+ has not returned normally."
+ (join-thread-error-thread c)))))
+
+#!+sb-doc
+(setf (fdocumentation 'join-thread-error-thread 'function)
+ "The thread that we failed to join.")
+
+(defun join-thread (thread &key (default nil defaultp))
+ #!+sb-doc
+ "Suspend current thread until THREAD exits. Returns the result
+values of the thread function. If the thread does not exit normally,
+return DEFAULT if given or else signal JOIN-THREAD-ERROR."
+ (with-mutex ((thread-result-lock thread))
+ (cond ((car (thread-result thread))
+ (values-list (cdr (thread-result thread))))
+ (defaultp
+ default)
+ (t
+ (error 'join-thread-error :thread thread)))))
(defun destroy-thread (thread)
#!+sb-doc
(terminate-thread thread))
(define-condition interrupt-thread-error (error)
- ((thread :reader interrupt-thread-error-thread :initarg :thread)
- (errno :reader interrupt-thread-error-errno :initarg :errno))
+ ((thread :reader interrupt-thread-error-thread :initarg :thread))
#!+sb-doc
(:documentation "Interrupting thread failed.")
(:report (lambda (c s)
- (format s "interrupt thread ~A failed (~A: ~A)"
- (interrupt-thread-error-thread c)
- (interrupt-thread-error-errno c)
- (strerror (interrupt-thread-error-errno c))))))
+ (format s "Interrupt thread failed: thread ~A has exited."
+ (interrupt-thread-error-thread c)))))
#!+sb-doc
-(setf (sb!kernel:fdocumentation 'interrupt-thread-error-thread 'function)
- "The thread that was not interrupted."
- (sb!kernel:fdocumentation 'interrupt-thread-error-errno 'function)
- "The reason why the interruption failed.")
+(setf (fdocumentation 'interrupt-thread-error-thread 'function)
+ "The thread that was not interrupted.")
+(defmacro with-interruptions-lock ((thread) &body body)
+ `(without-interrupts
+ (with-mutex ((thread-interruptions-lock ,thread))
+ ,@body)))
+
+;; Called from the signal handler.
+(defun run-interruption ()
+ (in-interruption ()
+ (loop
+ (let ((interruption (with-interruptions-lock (*current-thread*)
+ (pop (thread-interruptions *current-thread*)))))
+ (if interruption
+ (with-interrupts
+ (funcall interruption))
+ (return))))))
+
+;; The order of interrupt execution is peculiar. If thread A
+;; interrupts thread B with I1, I2 and B for some reason receives I1
+;; when FUN2 is already on the list, then it is FUN2 that gets to run
+;; first. But when FUN2 is run SIG_INTERRUPT_THREAD is enabled again
+;; and I2 hits pretty soon in FUN2 and run FUN1. This is of course
+;; just one scenario, and the order of thread interrupt execution is
+;; undefined.
(defun interrupt-thread (thread function)
#!+sb-doc
"Interrupt the live THREAD and make it run FUNCTION. A moderate
-degree of care is expected for use of interrupt-thread, due to its
+degree of care is expected for use of INTERRUPT-THREAD, due to its
nature: if you interrupt a thread that was holding important locks
then do something that turns out to need those locks, you probably
won't like the effect."
#!+sb-thread
(if (eq thread *current-thread*)
(funcall function)
- (let ((function (coerce function 'function)))
- (multiple-value-bind (res err)
- ;; protect against gcing just when the ub32 address is
- ;; just ready to be passed to C
- (sb!sys::with-pinned-objects (function)
- (sb!unix::syscall ("interrupt_thread"
- system-area-pointer sb!alien:unsigned-long)
- thread
- (thread-%sap thread)
- (sb!kernel:get-lisp-obj-address function)))
- (unless res
- (error 'interrupt-thread-error :thread thread :errno err))))))
+ (let ((os-thread (thread-os-thread thread)))
+ (cond ((not os-thread)
+ (error 'interrupt-thread-error :thread thread))
+ (t
+ (with-interruptions-lock (thread)
+ (push function (thread-interruptions thread)))
+ (when (minusp (signal-interrupt-thread os-thread))
+ (error 'interrupt-thread-error :thread thread)))))))
(defun terminate-thread (thread)
#!+sb-doc
;;; with an SBCL developer first, or are doing something that you
;;; should probably discuss with a professional psychiatrist first
#!+sb-thread
-(defun symbol-value-in-thread (symbol thread)
- (let ((thread-sap (thread-%sap thread)))
- (let* ((index (sb!vm::symbol-tls-index symbol))
- (tl-val (sb!sys:sap-ref-word thread-sap
- (* sb!vm:n-word-bytes index))))
- (if (eql tl-val sb!vm::no-tls-value-marker-widetag)
- (sb!vm::symbol-global-value symbol)
- (sb!kernel:make-lisp-obj tl-val)))))
+(defun thread-sap-for-id (id)
+ (let ((thread-sap (alien-sap (extern-alien "all_threads" (* t)))))
+ (loop
+ (when (sap= thread-sap (int-sap 0)) (return nil))
+ (let ((os-thread (sap-ref-word thread-sap
+ (* sb!vm:n-word-bytes
+ sb!vm::thread-os-thread-slot))))
+ (when (= os-thread id) (return thread-sap))
+ (setf thread-sap
+ (sap-ref-sap thread-sap (* sb!vm:n-word-bytes
+ sb!vm::thread-next-slot)))))))
+
+#!+sb-thread
+(defun symbol-value-in-thread (symbol thread-sap)
+ (let* ((index (sb!vm::symbol-tls-index symbol))
+ (tl-val (sap-ref-word thread-sap
+ (* sb!vm:n-word-bytes index))))
+ (if (eql tl-val sb!vm::no-tls-value-marker-widetag)
+ (sb!vm::symbol-global-value symbol)
+ (make-lisp-obj tl-val))))
+
+(defun sb!vm::locked-symbol-global-value-add (symbol-name delta)
+ (sb!vm::locked-symbol-global-value-add symbol-name delta))
+
+;;; Stepping
+
+(defun thread-stepping ()
+ (make-lisp-obj
+ (sap-ref-word (current-thread-sap)
+ (* sb!vm::thread-stepping-slot sb!vm:n-word-bytes))))
+
+(defun (setf thread-stepping) (value)
+ (setf (sap-ref-word (current-thread-sap)
+ (* sb!vm::thread-stepping-slot sb!vm:n-word-bytes))
+ (get-lisp-obj-address value)))
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