-;;;; condition variables
-
-(defun condition-wait (queue lock)
- "Atomically release LOCK 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)))
- (unwind-protect
- (progn
- (get-spinlock queue 2 (current-thread-id))
- (wait-on-queue queue lock))
- ;; 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))))
-
-#!+sb-futex
-(defun condition-wait/futex (queue lock)
- (assert lock)
- (let ((value (mutex-value lock)))
- (unwind-protect
- (let ((me (current-thread-id)))
- ;; 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 lock)
- ;; Now we go to sleep using futex-wait. If anyone else
- ;; manages to grab LOCK 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.
- (get-mutex lock value))))
-
-
-(defun condition-notify (queue)
- "Notify one of the processes waiting on QUEUE"
- (with-spinlock (queue) (signal-queue-head queue)))
-
-#!+sb-futex
-(defun condition-notify/futex (queue)
- "Notify one of the processes waiting on QUEUE."
- (let ((me (current-thread-id)))
- ;; 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)))
-
-#!+sb-futex
-(defun condition-broadcast/futex (queue)
- (let ((me (current-thread-id)))
- (setf (waitqueue-data queue) me)
- (futex-wake (waitqueue-data-address queue) (ash 1 30))))
-
-(defun condition-broadcast (queue)
- "Notify all of the processes waiting on QUEUE."
- (with-spinlock (queue)
- (map nil #'signal-thread-to-dequeue (waitqueue-data queue))))
-
-;;; Futexes may be available at compile time but not runtime, so we
-;;; default to not using them unless os_init says they're available
-(defun maybe-install-futex-functions ()
- #!+sb-futex
- (unless (zerop (extern-alien "linux_supports_futex" int))
- (setf (fdefinition 'get-mutex) #'get-mutex/futex
- (fdefinition 'release-mutex) #'release-mutex/futex
- (fdefinition 'condition-wait) #'condition-wait/futex
- (fdefinition 'condition-broadcast) #'condition-broadcast/futex
- (fdefinition 'condition-notify) #'condition-notify/futex)
- t))
-
-(defun make-thread (function)
- (let* ((real-function (coerce function 'function))
- (tid
- (%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))))))))
- (with-mutex ((session-lock *session*))
- (pushnew tid (session-threads *session*)))
- tid))
-
-;;; 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))
-
-(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))))
-
-;;;; 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))))
-
-;;;; job control, independent listeners
-
-(defstruct session
- (lock (make-mutex))
- (threads nil)
- (interactive-threads nil)
- (interactive-threads-queue (make-waitqueue)))
-
-(defun new-session ()
- (let ((tid (current-thread-id)))
- (make-session :threads (list tid)
- :interactive-threads (list tid))))
-
-(defun init-job-control ()
- (setf *session* (new-session)))
-
-(defun %delete-thread-from-session (tid)
- (with-mutex ((session-lock *session*))
- (setf (session-threads *session*)
- (delete tid (session-threads *session*))
- (session-interactive-threads *session*)
- (delete tid (session-interactive-threads *session*)))))
-
-(defun call-with-new-session (fn)
- (%delete-thread-from-session (current-thread-id))
- (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)))))
-
-;;; this is called from a C signal handler: some signals may be masked
-(defun handle-thread-exit (tid)
- "Remove thread id TID from the session, if it's there"
- (%delete-thread-from-session tid))
-
-(defun terminate-session ()
- "Kill all threads in session exept for this one. Does nothing if current
-thread is not the foreground thread"
- (let* ((tid (current-thread-id))
- (to-kill
- (with-mutex ((session-lock *session*))
- (and (eql tid (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 (p to-kill)
- (unless (eql p tid) (terminate-thread p)))))
-
-;;; 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
-interactive."
- (prog1
- (with-mutex ((session-lock *session*))
- (not (member (current-thread-id)
- (session-interactive-threads *session*))))
- (get-foreground)))
-
-
-(defun get-foreground ()
- (let ((was-foreground t))
- (loop
- (with-mutex ((session-lock *session*))
- (let ((tid (current-thread-id))
- (int-t (session-interactive-threads *session*)))
- (when (eql (car int-t) tid)
- (unless was-foreground
- (format *query-io* "Resuming thread ~A~%" tid))
- (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler)
- (return-from get-foreground t))
- (setf was-foreground nil)
- (unless (member tid int-t)
- (setf (cdr (last int-t))
- (list tid)))
- (condition-wait
- (session-interactive-threads-queue *session*)
- (session-lock *session*)))))))
-
-(defun release-foreground (&optional next)
- "Background this thread. If NEXT is supplied, arrange for it to have the foreground next"
- (with-mutex ((session-lock *session*))
- (let ((tid (current-thread-id)))
- (setf (session-interactive-threads *session*)
- (delete tid (session-interactive-threads *session*)))
- (sb!sys:enable-interrupt sb!unix:sigint :ignore)
- (when next
- (setf (session-interactive-threads *session*)
- (list* next
- (delete next (session-interactive-threads *session*)))))
- (condition-broadcast (session-interactive-threads-queue *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))
- (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))
- (with-new-session ()
- (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))))
+(defstruct (thread (:constructor %make-thread))
+ name
+ %sap)
+
+(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 %set-thread-state (thread state)
+ (setf (sb!sys:sap-ref-sap (thread-%sap thread)
+ (* sb!vm::thread-state-slot
+ sb!vm::n-word-bytes))
+ (sb!sys:int-sap
+ (ecase state
+ (:starting #.(sb!vm:fixnumize 0))
+ (:running #.(sb!vm:fixnumize 1))
+ (:suspended #.(sb!vm:fixnumize 2))
+ (:dead #.(sb!vm:fixnumize 3))))))
+
+(defun thread-alive-p (thread)
+ (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 ()
+ (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))))