X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=ba386493a8df2556ac581f9c030bc78550a82520;hb=a98bbf0cf10b8136707995a00a1c7240c05d02a9;hp=9893bd887da23ae62c11c3b452e3592a5ec1f9fa;hpb=6b7b0266343826426a3efffa3b8b8d4d552f8f97;p=sbcl.git diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp index 9893bd8..ba38649 100644 --- a/src/code/target-thread.lisp +++ b/src/code/target-thread.lisp @@ -1,397 +1,590 @@ -(in-package "SB!THREAD") +;;;; support for threads in the target machine -(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 :sigint :ignore) - (sb!unix:unix-exit - (catch 'sb!impl::%end-of-the-world - (with-simple-restart - (destroy-thread - (format nil "~~@" - (current-thread-id))) - (funcall real-function)) - 0)))))))) - -;;; Conventional wisdom says that it's a bad idea to use these unless -;;; you really need to. Use a lock or a waitqueue instead -(defun suspend-thread (thread-id) - (sb!unix:unix-kill thread-id :sigstop)) -(defun resume-thread (thread-id) - (sb!unix:unix-kill thread-id :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 :sigterm) - ;; may have been stopped for some reason, so now wake it up to - ;; deliver the TERM - (sb!unix:unix-kill thread-id :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)) +;;;; 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") -(defun current-thread-id () +;;; 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-pid-slot))) - -;;;; 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)))) - -;;;; queues, locks - -;; spinlocks use 0 as "free" value: higher-level locks use NIL -(defun get-spinlock (lock offset new-value) - (declare (optimize (speed 3) (safety 0))) + (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)) + +(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) + (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))) - -(defmacro with-spinlock ((queue) &body body) - (with-unique-names (pid) - `(unwind-protect - (let ((,pid (current-thread-id))) - (get-spinlock ,queue 2 ,pid) - ,@body) - (setf (waitqueue-lock ,queue) 0)))) + (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))) - ;; FIXME what should happen if we get interrupted when we've blocked - ;; the sigcont? For that matter, can we get interrupted? - (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 probably only be called while holding the queue spinlock. -;;; not sure -(defun signal-queue-head (queue) - (let ((p (car (waitqueue-data queue)))) - (when p (sb!unix:unix-kill p :sigcont)))) - -;;;; mutex - -(defun get-mutex (lock &optional new-value (wait-p t)) - (declare (type mutex lock)) - (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 :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 ((pid (current-thread-id)) - (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 + "~~@" + *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::unbound-marker-widetag) + (sb!vm::symbol-global-value symbol) + (sb!kernel:make-lisp-obj tl-val)))))