-(in-package "SB!THREAD")
-
-(sb!alien::define-alien-routine ("create_thread" %create-thread)
- sb!alien:unsigned-long
- (lisp-fun-address sb!alien:unsigned-long))
-
-(defun make-thread (function)
- (let ((real-function (coerce function 'function)))
- (%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 ((sb!kernel::*restart-clusters* nil)
- (sb!impl::*descriptor-handlers* nil); serve-event
- (sb!impl::*available-buffers* nil)) ;for fd-stream
- ;; 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)
- (sb!sys:enable-interrupt sb!unix:sigint :ignore)
- (sb!unix:unix-exit
- (catch 'sb!impl::%end-of-the-world
- (with-simple-restart
- (destroy-thread
- (format nil "~~@<Destroy this thread (~A)~~@:>"
- (current-thread-id)))
- (funcall real-function))
- 0))))))))
-
-;;; Really, you don't want to use these: they'll get into trouble with
-;;; garbage collection. Use a lock or a waitqueue instead
-(defun suspend-thread (thread-id)
- (sb!unix:unix-kill thread-id sb!unix:sigstop))
-(defun resume-thread (thread-id)
- (sb!unix:unix-kill thread-id sb!unix:sigcont))
-;;; Note warning about cleanup forms
-(defun destroy-thread (thread-id)
- "Destroy the thread identified by THREAD-ID abruptly, without running cleanup forms"
- (sb!unix:unix-kill thread-id sb!unix:sigterm)
- ;; may have been stopped for some reason, so now wake it up to
- ;; deliver the TERM
- (sb!unix:unix-kill thread-id sb!unix:sigcont))
-
-
-;;; a moderate 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. Used with thought
-;;; though, it's a good deal gentler than the last-resort functions above
-
-(defun interrupt-thread (thread function)
- "Interrupt THREAD and make it run FUNCTION. "
- (sb!unix::syscall* ("interrupt_thread"
- sb!alien:unsigned-long sb!alien:unsigned-long)
- thread
- thread (sb!kernel:get-lisp-obj-address
- (coerce function 'function))))
-(defun terminate-thread (thread-id)
- "Terminate the thread identified by THREAD-ID, by causing it to run
-SB-EXT:QUIT - the usual cleanup forms will be evaluated"
- (interrupt-thread thread-id 'sb!ext:quit))
+;;;; support for threads in the target machine
-(declaim (inline current-thread-id))
-(defun current-thread-id ()
- (logand
- (sb!sys:sap-int
- (sb!vm::current-thread-offset-sap sb!vm::thread-pid-slot))
- ;; KLUDGE pids are 16 bit really. Avoid boxing the return value
- (1- (ash 1 16))))
+;;;; 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.
-;;;; iterate over the in-memory threads
-
-(defun mapcar-threads (function)
- "Call FUNCTION once for each known thread, giving it the thread structure as argument"
- (let ((function (coerce function 'function)))
- (loop for thread = (alien-sap (extern-alien "all_threads" (* t)))
- then (sb!sys:sap-ref-sap thread (* 4 sb!vm::thread-next-slot))
- until (sb!sys:sap= thread (sb!sys:int-sap 0))
- collect (funcall function thread))))
+(in-package "SB!THREAD")
-;;;; queues, locks
+;;; set the doc here because in early-thread FDOCUMENTATION is not
+;;; available, yet
+#!+sb-doc
+(setf (sb!kernel:fdocumentation '*current-thread* 'variable)
+ "Bound in each thread to the thread itself.")
+
+(defstruct (thread (:constructor %make-thread))
+ #!+sb-doc
+ "Thread type. Do not rely on threads being structs as it may change
+in future versions."
+ name
+ %sap)
+
+#!+sb-doc
+(setf (sb!kernel:fdocumentation 'thread-name 'function)
+ "The name of the thread. Setfable.")
+
+(def!method print-object ((thread thread) stream)
+ (if (thread-name thread)
+ (print-unreadable-object (thread stream :type t :identity t)
+ (prin1 (thread-name thread) stream))
+ (print-unreadable-object (thread stream :type t :identity t)
+ ;; body is empty => there is only one space between type and
+ ;; identity
+ ))
+ 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))))
+
+;; 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
+;; all running threads.
+(defvar *all-threads* ())
+(defvar *all-threads-lock* (make-mutex :name "all threads lock"))
+
+(defun list-all-threads ()
+ #!+sb-doc
+ "Return a list of the live threads."
+ (with-mutex (*all-threads-lock*)
+ (copy-list *all-threads*)))
+
+(declaim (inline current-thread-sap))
+(defun current-thread-sap ()
+ (sb!vm::current-thread-offset-sap sb!vm::thread-this-slot))
+
+(declaim (inline current-thread-sap-id))
+(defun current-thread-sap-id ()
+ (sb!sys:sap-int
+ (sb!vm::current-thread-offset-sap sb!vm::thread-os-thread-slot)))
+
+(defun init-initial-thread ()
+ (let ((initial-thread (%make-thread :name "initial thread"
+ :%sap (current-thread-sap))))
+ (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
+ ;; threads doesn't work.
+ (setq *all-threads* (list initial-thread))))
+
+;;;;
+
+#!+sb-thread
+(progn
+ (define-alien-routine ("create_thread" %create-thread)
+ system-area-pointer
+ (lisp-fun-address unsigned-long))
+
+ (define-alien-routine "block_blockable_signals"
+ void)
+
+ (define-alien-routine reap-dead-thread void
+ (thread-sap system-area-pointer))
+
+ (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))
+#!-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)))
+ (* n sb!vm:n-word-bytes)))
+
+;;;; spinlocks
+
+(defstruct spinlock
+ #!+sb-doc
+ "Spinlock type."
+ (name nil :type (or null simple-string))
+ (value 0))
-;; spinlocks use 0 as "free" value: higher-level locks use NIL
(declaim (inline get-spinlock release-spinlock))
-(defun get-spinlock (lock offset new-value)
- (declare (optimize (speed 3) (safety 0)))
+;;; 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)
+ (declare (optimize (speed 3) (safety 0))
+ #!-sb-thread
+ (ignore spinlock new-value))
+ ;; %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 lock offset 0 new-value) 0)))
-
-;; this should do nothing if we didn't own the lock, so safe to use in
-;; unwind-protect cleanups when lock acquisition failed for some reason
-(defun release-spinlock (lock offset our-value)
- (declare (optimize (speed 3) (safety 0)))
- (sb!vm::%instance-set-conditional lock offset our-value 0))
-
-(defmacro with-spinlock ((queue) &body body)
- (with-unique-names (pid)
- `(let ((,pid (current-thread-id)))
- (unwind-protect
- (progn
- (get-spinlock ,queue 2 ,pid)
- ,@body)
- (release-spinlock ,queue 2 ,pid)))))
-
+ (eql (sb!vm::%instance-set-conditional spinlock 2 0 new-value) 0)))
+
+(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)
+ ;; 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)))))
-;;;; the higher-level locking operations are based on waitqueues
+;;;; mutexes
-(defstruct waitqueue
- (name nil :type (or null simple-base-string))
- (lock 0)
- (data nil))
-
-(defstruct (mutex (:include waitqueue))
+(defstruct mutex
+ #!+sb-doc
+ "Mutex type."
+ (name nil :type (or null simple-string))
(value nil))
-(sb!alien:define-alien-routine "block_sigcont" void)
-(sb!alien:define-alien-routine "unblock_sigcont_and_sleep" void)
-
-
-;;; this should only be called while holding the queue spinlock.
-;;; it releases the spinlock before sleeping
-(defun wait-on-queue (queue &optional lock)
- (let ((pid (current-thread-id)))
- (block-sigcont)
- (when lock (release-mutex lock))
- (sb!sys:without-interrupts
- (pushnew pid (waitqueue-data queue)))
- (setf (waitqueue-lock queue) 0)
- (unblock-sigcont-and-sleep)))
-
-;;; this should only be called while holding the queue spinlock. It doesn't
-;;; release it
-(defun dequeue (queue)
- (let ((pid (current-thread-id)))
- (sb!sys:without-interrupts
- (setf (waitqueue-data queue)
- (delete pid (waitqueue-data queue))))))
-
-;;; this should only be called while holding the queue spinlock.
-(defun signal-queue-head (queue)
- (let ((p (car (waitqueue-data queue))))
- (when p (sb!unix:unix-kill p sb!unix::sig-dequeue))))
-
-;;;; mutex
-
-(defun get-mutex (lock &optional new-value (wait-p t))
- (declare (type mutex lock)
- (optimize (speed 3)))
- (let ((pid (current-thread-id)))
- (unless new-value (setf new-value pid))
- (assert (not (eql new-value (mutex-value lock))))
- (get-spinlock lock 2 pid)
+#!+sb-doc
+(setf (sb!kernel:fdocumentation 'make-mutex 'function)
+ "Create a mutex."
+ (sb!kernel:fdocumentation 'mutex-name 'function)
+ "The name of the mutex. Setfable."
+ (sb!kernel: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))
+ #!+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"
+ (declare (type mutex mutex) (optimize (speed 3)))
+ (unless new-value (setf new-value *current-thread*))
+ #!-sb-thread
+ (let ((old-value (mutex-value mutex)))
+ (when (and old-value wait-p)
+ (error "In unithread mode, mutex ~S was requested with WAIT-P ~S and ~
+ new-value ~S, but has already been acquired (with value ~S)."
+ mutex wait-p new-value old-value))
+ (setf (mutex-value mutex) new-value)
+ t)
+ #!+sb-thread
+ (let (old)
+ (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
- ;; args are object slot-num old-value new-value
- (sb!vm::%instance-set-conditional lock 4 nil new-value)
- (dequeue lock)
- (setf (waitqueue-lock lock) 0)
+ (setf old (sb!vm::%instance-set-conditional mutex 2 nil new-value))
(return t))
- (unless wait-p
- (setf (waitqueue-lock lock) 0)
- (return nil))
- (wait-on-queue lock nil))))
-
-(defun release-mutex (lock &optional (new-value nil))
- (declare (type mutex lock))
- ;; we assume the lock is ours to release
- (with-spinlock (lock)
- (setf (mutex-value lock) new-value)
- (signal-queue-head lock)))
-
-
-(defmacro with-mutex ((mutex &key value (wait-p t)) &body body)
- (with-unique-names (got)
- `(let ((,got (get-mutex ,mutex ,value ,wait-p)))
- (when ,got
- (unwind-protect
- (progn ,@body)
- (release-mutex ,mutex))))))
-
-
-;;;; condition variables
+ (unless wait-p (return nil))
+ (futex-wait (mutex-value-address mutex)
+ (sb!kernel: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))
+ (setf (mutex-value mutex) nil)
+ #!+sb-thread
+ (futex-wake (mutex-value-address mutex) 1))
+
+;;;; waitqueues/condition variables
+
+(defstruct (waitqueue (:constructor %make-waitqueue))
+ #!+sb-doc
+ "Waitqueue type."
+ (name nil :type (or null simple-string))
+ (data nil))
-(defun condition-wait (queue lock)
- "Atomically release LOCK and enqueue ourselves on QUEUE. Another
+(defun make-waitqueue (&key name)
+ #!+sb-doc
+ "Create a waitqueue."
+ (%make-waitqueue :name name))
+
+#!+sb-doc
+(setf (sb!kernel: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))))
+
+(defun condition-wait (queue mutex)
+ #!+sb-doc
+ "Atomically release MUTEX and enqueue ourselves on QUEUE. Another
thread may subsequently notify us using CONDITION-NOTIFY, at which
-time we reacquire LOCK and return to the caller."
- (assert lock)
- (let ((value (mutex-value lock)))
+time we reacquire MUTEX and return to the caller."
+ #!-sb-thread (declare (ignore queue))
+ (assert mutex)
+ #!-sb-thread (error "Not supported in unithread builds.")
+ #!+sb-thread
+ (let ((value (mutex-value mutex)))
(unwind-protect
- (progn
- (get-spinlock queue 2 (current-thread-id))
- (wait-on-queue queue lock))
+ (let ((me *current-thread*))
+ ;; XXX we should do something to ensure that the result of this setf
+ ;; is visible to all CPUs
+ (setf (waitqueue-data queue) me)
+ (release-mutex mutex)
+ ;; Now we go to sleep using futex-wait. If anyone else
+ ;; manages to grab MUTEX and call CONDITION-NOTIFY during
+ ;; 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)))
;; 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
;; better than nothing.
- (with-spinlock (queue)
- (dequeue queue))
- (get-mutex lock value))))
+ (get-mutex mutex value))))
(defun condition-notify (queue)
- "Notify one of the processes waiting on QUEUE"
- (with-spinlock (queue) (signal-queue-head queue)))
-
-
-;;;; multiple independent listeners
-
-(defvar *session-lock* nil)
-
-(defun make-listener-thread (tty-name)
- (assert (probe-file tty-name))
- ;; FIXME probably still need to do some tty stuff to get signals
- ;; delivered correctly.
- ;; FIXME
- (let* ((in (sb!unix:unix-open (namestring tty-name) sb!unix:o_rdwr #o666))
- (out (sb!unix:unix-dup in))
- (err (sb!unix:unix-dup in)))
- (labels ((thread-repl ()
- (sb!unix::unix-setsid)
- (let* ((*session-lock*
- (make-mutex :name (format nil "lock for ~A" tty-name)))
- (sb!impl::*stdin*
- (sb!sys:make-fd-stream in :input t :buffering :line))
- (sb!impl::*stdout*
- (sb!sys:make-fd-stream out :output t :buffering :line))
- (sb!impl::*stderr*
- (sb!sys:make-fd-stream err :output t :buffering :line))
- (sb!impl::*tty*
- (sb!sys:make-fd-stream err :input t :output t :buffering :line))
- (sb!impl::*descriptor-handlers* nil))
- (get-mutex *session-lock*)
- (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler)
- (unwind-protect
- (sb!impl::toplevel-repl nil)
- (sb!int:flush-standard-output-streams)))))
- (make-thread #'thread-repl))))
-
-;;;; job control
-
-(defvar *background-threads-wait-for-debugger* t)
-;;; may be T, NIL, or a function called with a stream and thread id
-;;; as its two arguments, returning NIl or T
+ #!+sb-doc
+ "Notify one of the threads waiting on QUEUE."
+ #!-sb-thread (declare (ignore queue))
+ #!-sb-thread (error "Not supported in unithread builds.")
+ #!+sb-thread
+ (let ((me *current-thread*))
+ ;; 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) 1)))
+
+(defun condition-broadcast (queue)
+ #!+sb-doc
+ "Notify all threads waiting on QUEUE."
+ #!-sb-thread (declare (ignore queue))
+ #!-sb-thread (error "Not supported in unithread builds.")
+ #!+sb-thread
+ (let ((me *current-thread*))
+ (setf (waitqueue-data queue) me)
+ (futex-wake (waitqueue-data-address queue) (ash 1 30))))
+
+;;;; job control, independent listeners
+
+(defstruct session
+ (lock (make-mutex :name "session lock"))
+ (threads nil)
+ (interactive-threads nil)
+ (interactive-threads-queue (make-waitqueue)))
+
+(defvar *session* nil)
+
+;;; the debugger itself tries to acquire the session lock, don't let
+;;; funny situations (like getting a sigint while holding the session
+;;; lock) occur
+(defmacro with-session-lock ((session) &body body)
+ #!-sb-thread (declare (ignore session))
+ #!-sb-thread
+ `(locally ,@body)
+ #!+sb-thread
+ `(sb!sys: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)))
+
+(defun %delete-thread-from-session (thread session)
+ (with-session-lock (session)
+ (setf (session-threads session)
+ (delete thread (session-threads session))
+ (session-interactive-threads session)
+ (delete thread (session-interactive-threads session)))))
+
+(defun call-with-new-session (fn)
+ (%delete-thread-from-session *current-thread* *session*)
+ (let ((*session* (new-session)))
+ (funcall fn)))
+
+(defmacro with-new-session (args &body forms)
+ (declare (ignore args)) ;for extensibility
+ (sb!int:with-unique-names (fb-name)
+ `(labels ((,fb-name () ,@forms))
+ (call-with-new-session (function ,fb-name)))))
+
+;;; 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*)))
+
+(defun terminate-session ()
+ #!+sb-doc
+ "Kill all threads in session except for this one. Does nothing if current
+thread is not the foreground thread."
+ ;; FIXME: threads created in other threads may escape termination
+ (let ((to-kill
+ (with-session-lock (*session*)
+ (and (eq *current-thread*
+ (car (session-interactive-threads *session*)))
+ (session-threads *session*)))))
+ ;; do the kill after dropping the mutex; unwind forms in dying
+ ;; threads may want to do session things
+ (dolist (thread to-kill)
+ (unless (eq thread *current-thread*)
+ ;; terminate the thread but don't be surprised if it has
+ ;; exited in the meantime
+ (handler-case (terminate-thread thread)
+ (interrupt-thread-error ()))))))
;;; called from top of invoke-debugger
(defun debugger-wait-until-foreground-thread (stream)
"Returns T if thread had been running in background, NIL if it was
-already the foreground thread, or transfers control to the first applicable
-restart if *BACKGROUND-THREADS-WAIT-FOR-DEBUGGER* says to do that instead"
- (let* ((wait-p *background-threads-wait-for-debugger*)
- (*background-threads-wait-for-debugger* nil)
- (lock *session-lock*))
- (when (not (eql (mutex-value lock) (CURRENT-THREAD-ID)))
- (when (functionp wait-p)
- (setf wait-p
- (funcall wait-p stream (CURRENT-THREAD-ID))))
- (cond (wait-p (get-foreground))
- (t (invoke-restart (car (compute-restarts))))))))
-
-;;; install this with
-;;; (setf SB-INT:*REPL-PROMPT-FUN* #'sb-thread::thread-repl-prompt-fun)
-;;; One day it will be default
-(defun thread-repl-prompt-fun (out-stream)
- (let ((lock *session-lock*))
- (get-foreground)
- (let ((stopped-threads (waitqueue-data lock)))
- (when stopped-threads
- (format out-stream "~{~&Thread ~A suspended~}~%" stopped-threads))
- (sb!impl::repl-prompt-fun out-stream))))
-
-(defun resume-stopped-thread (id)
- (let ((lock *session-lock*))
- (with-spinlock (lock)
- (setf (waitqueue-data lock)
- (cons id (delete id (waitqueue-data lock)))))
- (release-foreground)))
-
-(defstruct rwlock
- (name nil :type (or null simple-base-string))
- (value 0 :type fixnum)
- (max-readers nil :type (or fixnum null))
- (max-writers 1 :type fixnum))
-#+nil
-(macrolet
- ((make-rwlocking-function (lock-fn unlock-fn increment limit test)
- (let ((do-update '(when (eql old-value
- (sb!vm::%instance-set-conditional
- lock 2 old-value new-value))
- (return (values t old-value))))
- (vars `((timeout (and timeout (+ (get-internal-real-time) timeout)))
- old-value
- new-value
- (limit ,limit))))
- (labels ((do-setfs (v) `(setf old-value (rwlock-value lock)
- new-value (,v old-value ,increment))))
- `(progn
- (defun ,lock-fn (lock timeout)
- (declare (type rwlock lock))
- (let ,vars
- (loop
- ,(do-setfs '+)
- (when ,test
- ,do-update)
- (when (sleep-a-bit timeout) (return nil)) ;expired
- )))
- ;; unlock doesn't need timeout or test-in-range
- (defun ,unlock-fn (lock)
- (declare (type rwlock lock))
- (declare (ignorable limit))
- (let ,(cdr vars)
- (loop
- ,(do-setfs '-)
- ,do-update))))))))
-
- (make-rwlocking-function %lock-for-reading %unlock-for-reading 1
- (rwlock-max-readers lock)
- (and (>= old-value 0)
- (or (null limit) (<= new-value limit))))
- (make-rwlocking-function %lock-for-writing %unlock-for-writing -1
- (- (rwlock-max-writers lock))
- (and (<= old-value 0)
- (>= new-value limit))))
-#+nil
-(defun get-rwlock (lock direction &optional timeout)
- (ecase direction
- (:read (%lock-for-reading lock timeout))
- (:write (%lock-for-writing lock timeout))))
-#+nil
-(defun free-rwlock (lock direction)
- (ecase direction
- (:read (%unlock-for-reading lock))
- (:write (%unlock-for-writing lock))))
-
-;;;; beyond this point all is commented.
-
-;;; Lock-Wait-With-Timeout -- Internal
-;;;
-;;; Wait with a timeout for the lock to be free and acquire it for the
-;;; *current-process*.
-;;;
-#+nil
-(defun lock-wait-with-timeout (lock whostate timeout)
- (declare (type lock lock))
- (process-wait-with-timeout
- whostate timeout
- #'(lambda ()
- (declare (optimize (speed 3)))
- #-i486
- (unless (lock-process lock)
- (setf (lock-process lock) *current-process*))
- #+i486
- (null (kernel:%instance-set-conditional
- lock 2 nil *current-process*)))))
-
-;;; With-Lock-Held -- Public
-;;;
-#+nil
-(defmacro with-lock-held ((lock &optional (whostate "Lock Wait")
- &key (wait t) timeout)
- &body body)
- "Execute the body with the lock held. If the lock is held by another
- process then the current process waits until the lock is released or
- an optional timeout is reached. The optional wait timeout is a time in
- seconds acceptable to process-wait-with-timeout. The results of the
- body are return upon success and NIL is return if the timeout is
- reached. When the wait key is NIL and the lock is held by another
- process then NIL is return immediately without processing the body."
- (let ((have-lock (gensym)))
- `(let ((,have-lock (eq (lock-process ,lock) *current-process*)))
- (unwind-protect
- ,(cond ((and timeout wait)
- `(progn
- (when (and (error-check-lock-p ,lock) ,have-lock)
- (error "Dead lock"))
- (when (or ,have-lock
- #+i486 (null (kernel:%instance-set-conditional
- ,lock 2 nil *current-process*))
- #-i486 (seize-lock ,lock)
- (if ,timeout
- (lock-wait-with-timeout
- ,lock ,whostate ,timeout)
- (lock-wait ,lock ,whostate)))
- ,@body)))
- (wait
- `(progn
- (when (and (error-check-lock-p ,lock) ,have-lock)
- (error "Dead lock"))
- (unless (or ,have-lock
- #+i486 (null (kernel:%instance-set-conditional
- ,lock 2 nil *current-process*))
- #-i486 (seize-lock ,lock))
- (lock-wait ,lock ,whostate))
- ,@body))
- (t
- `(when (or (and (recursive-lock-p ,lock) ,have-lock)
- #+i486 (null (kernel:%instance-set-conditional
- ,lock 2 nil *current-process*))
- #-i486 (seize-lock ,lock))
- ,@body)))
- (unless ,have-lock
- #+i486 (kernel:%instance-set-conditional
- ,lock 2 *current-process* nil)
- #-i486 (when (eq (lock-process ,lock) *current-process*)
- (setf (lock-process ,lock) nil)))))))
-
+interactive."
+ (declare (ignore stream))
+ #!-sb-thread nil
+ #!+sb-thread
+ (prog1
+ (with-session-lock (*session*)
+ (not (member *current-thread*
+ (session-interactive-threads *session*))))
+ (get-foreground)))
+
+(defun get-foreground ()
+ #!-sb-thread t
+ #!+sb-thread
+ (let ((was-foreground t))
+ (loop
+ (with-session-lock (*session*)
+ (let ((int-t (session-interactive-threads *session*)))
+ (when (eq (car int-t) *current-thread*)
+ (unless was-foreground
+ (format *query-io* "Resuming thread ~A~%" *current-thread*))
+ (return-from get-foreground t))
+ (setf was-foreground nil)
+ (unless (member *current-thread* int-t)
+ (setf (cdr (last int-t))
+ (list *current-thread*)))
+ (condition-wait
+ (session-interactive-threads-queue *session*)
+ (session-lock *session*)))))))
+
+(defun release-foreground (&optional next)
+ #!+sb-doc
+ "Background this thread. If NEXT is supplied, arrange for it to
+have the foreground next."
+ #!-sb-thread (declare (ignore next))
+ #!-sb-thread nil
+ #!+sb-thread
+ (with-session-lock (*session*)
+ (when (rest (session-interactive-threads *session*))
+ (setf (session-interactive-threads *session*)
+ (delete *current-thread* (session-interactive-threads *session*))))
+ (when next
+ (setf (session-interactive-threads *session*)
+ (list* next
+ (delete next (session-interactive-threads *session*)))))
+ (condition-broadcast (session-interactive-threads-queue *session*))))
+
+(defun foreground-thread ()
+ (car (session-interactive-threads *session*)))
+
+(defun make-listener-thread (tty-name)
+ (assert (probe-file tty-name))
+ (let* ((in (sb!unix:unix-open (namestring tty-name) sb!unix:o_rdwr #o666))
+ (out (sb!unix:unix-dup in))
+ (err (sb!unix:unix-dup in)))
+ (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))
+ (sb!impl::*stdout*
+ (sb!sys: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
+ :dual-channel-p t))
+ (sb!impl::*tty*
+ (sb!sys:make-fd-stream err :input t :output t
+ :buffering :line
+ :dual-channel-p t))
+ (sb!impl::*descriptor-handlers* nil))
+ (with-new-session ()
+ (unwind-protect
+ (sb!impl::toplevel-repl nil)
+ (sb!int:flush-standard-output-streams))))))
+ (make-thread #'thread-repl))))
+;;;; the beef
+
+(defun make-thread (function &key name)
+ #!+sb-doc
+ "Create a new thread of NAME that runs FUNCTION. When the function
+returns the thread exits."
+ #!-sb-thread (declare (ignore function name))
+ #!-sb-thread (error "Not supported in unithread builds.")
+ #!+sb-thread
+ (let* ((thread (%make-thread :name name))
+ (setup-p nil)
+ (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 ()
+ ;; FIXME: use semaphores?
+ (loop until setup-p)
+ ;; 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
+ ;; 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*))
+ ;; 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*)))
+ (setq setup-p t)
+ (sb!impl::finalize thread (lambda () (reap-dead-thread thread-sap)))
+ thread))
+
+(defun destroy-thread (thread)
+ #!+sb-doc
+ "Deprecated. Same as TERMINATE-THREAD."
+ (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))
+ #!+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))))))
+
+#!+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.")
+(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
+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 (declare (ignore thread))
+ ;; not quite perfect, because it does not take WITHOUT-INTERRUPTS
+ ;; into account
+ #!-sb-thread
+ (funcall function)
+ #!+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))))))
+
+(defun terminate-thread (thread)
+ #!+sb-doc
+ "Terminate the thread identified by THREAD, by causing it to run
+SB-EXT:QUIT - the usual cleanup forms will be evaluated"
+ (interrupt-thread thread 'sb!ext:quit))
+
+;;; internal use only. If you think you need to use this, either you
+;;; are an SBCL developer, are doing something that you should discuss
+;;; 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)))))
projects / sbcl.git / blobdiff