X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=c534ca01fb2e94e0b61973ecc1322602059ac56a;hb=ee222567ee95eaac8f6f4c877242dd116bfb8337;hp=9296ce12d93235052f3f8c3b2ccbed2beacbf5c7;hpb=62b2ddf8075c1b82fdb7e8583353e446bb8ed6f3;p=sbcl.git diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp index 9296ce1..c534ca0 100644 --- a/src/code/target-thread.lisp +++ b/src/code/target-thread.lisp @@ -19,7 +19,7 @@ ;;; 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)) @@ -30,21 +30,31 @@ in future versions." %alive-p os-thread interruptions - (interruptions-lock (make-mutex :name "thread interruptions lock"))) + (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) - (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) + (print-unreadable-object (thread stream :type t :identity t) + (let* ((cookie (list thread)) + (info (if (thread-alive-p thread) + :running + (multiple-value-list (join-thread thread :default cookie)))) + (state (if (eq :running info) + info + (if (eq cookie (car info)) + :aborted + :finished))) + (values (when (eq :finished state) info))) + (format stream "~@[~S ~]~:[~A~;~A~:[ no values~; values: ~:*~{~S~^, ~}~]~]" + (thread-name thread) + (eq :finished state) + state + values)))) (defun thread-alive-p (thread) #!+sb-doc @@ -57,18 +67,24 @@ in future versions." (defvar *all-threads* ()) (defvar *all-threads-lock* (make-mutex :name "all threads lock")) +(defvar *default-alloc-signal* nil) + +(defmacro with-all-threads-lock (&body body) + `(with-system-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)) (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 () +(declaim (inline current-thread-os-thread)) +(defun current-thread-os-thread () (sap-int (sb!vm::current-thread-offset-sap sb!vm::thread-os-thread-slot))) @@ -76,7 +92,7 @@ in future versions." (/show0 "Entering INIT-INITIAL-THREAD") (let ((initial-thread (%make-thread :name "initial thread" :%alive-p t - :os-thread (current-thread-sap-id)))) + :os-thread (current-thread-os-thread)))) (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 @@ -97,7 +113,7 @@ in future versions." (define-alien-routine "signal_interrupt_thread" integer (os-thread unsigned-long)) - (define-alien-routine "block_blockable_signals" + (define-alien-routine "block_deferrable_signals" void) #!+sb-lutex @@ -105,22 +121,25 @@ in future versions." (declaim (inline %lutex-init %lutex-wait %lutex-wake %lutex-lock %lutex-unlock)) - (sb!alien:define-alien-routine ("lutex_init" %lutex-init) + (define-alien-routine ("lutex_init" %lutex-init) int (lutex unsigned-long)) - (sb!alien:define-alien-routine ("lutex_wait" %lutex-wait) + (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) + (define-alien-routine ("lutex_wake" %lutex-wake) int (lutex unsigned-long) (n int)) - (sb!alien:define-alien-routine ("lutex_lock" %lutex-lock) + (define-alien-routine ("lutex_lock" %lutex-lock) + int (lutex unsigned-long)) + + (define-alien-routine ("lutex_trylock" %lutex-trylock) int (lutex unsigned-long)) - (sb!alien:define-alien-routine ("lutex_unlock" %lutex-unlock) + (define-alien-routine ("lutex_unlock" %lutex-unlock) int (lutex unsigned-long)) - (sb!alien:define-alien-routine ("lutex_destroy" %lutex-destroy) + (define-alien-routine ("lutex_destroy" %lutex-destroy) int (lutex unsigned-long)) ;; FIXME: Defining a whole bunch of alien-type machinery just for @@ -130,7 +149,7 @@ in future versions." (defmacro with-lutex-address ((name lutex) &body body) `(let ((,name ,lutex)) (with-pinned-objects (,name) - (let ((,name (sb!kernel:get-lisp-obj-address ,name))) + (let ((,name (get-lisp-obj-address ,name))) ,@body)))) (defun make-lutex () @@ -147,132 +166,192 @@ in future versions." #!-sb-lutex (progn - (declaim (inline futex-wait futex-wake)) + (declaim (inline futex-wait %futex-wait futex-wake)) + + (define-alien-routine ("futex_wait" %futex-wait) + int (word unsigned-long) (old-value unsigned-long) + (to-sec long) (to-usec unsigned-long)) - (sb!alien:define-alien-routine "futex_wait" - int (word unsigned-long) (old-value unsigned-long)) + (defun futex-wait (word old to-sec to-usec) + (with-interrupts + (%futex-wait word old to-sec to-usec))) - (sb!alien:define-alien-routine "futex_wake" + (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)) (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)) (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 +;; Should always be called with interrupts disabled. (defun get-spinlock (spinlock) - (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 spinlock 2 0 1) 0))) + (declare (optimize (speed 3) (safety 0))) + (let* ((new *current-thread*) + (old (sb!ext:compare-and-swap (spinlock-value spinlock) nil new))) + (when old + (when (eq old new) + (error "Recursive lock attempt on ~S." spinlock)) + #!+sb-thread + (flet ((cas () + (if (sb!ext:compare-and-swap (spinlock-value spinlock) nil new) + (thread-yield) + (return-from get-spinlock t)))) + (if (and (not *interrupts-enabled*) *allow-with-interrupts*) + ;; If interrupts are enabled, but we are allowed to enabled them, + ;; check for pending interrupts every once in a while. + (loop + (loop repeat 128 do (cas)) ; 128 is arbitrary here + (sb!unix::%check-interrupts)) + (loop (cas))))) + 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) - ;; 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) - (unwind-protect - (progn ,@body) - (release-spinlock ,lock))))) + (declare (optimize (speed 3) (safety 0))) + (setf (spinlock-value spinlock) nil) + nil) ;;;; mutexes #!+sb-doc -(setf (sb!kernel:fdocumentation 'make-mutex 'function) +(setf (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.") + (fdocumentation 'mutex-name 'function) + "The name of the mutex. Setfable.") #!+(and sb-thread (not sb-lutex)) (progn - (declaim (inline mutex-value-address)) - (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 *current-thread*) (wait-p t)) + (define-structure-slot-addressor mutex-state-address + :structure mutex + :slot state) + ;; Important: current code assumes these are fixnums or other + ;; lisp objects that don't need pinning. + (defconstant +lock-free+ 0) + (defconstant +lock-taken+ 1) + (defconstant +lock-contested+ 2)) + +(defun get-mutex (mutex &optional (new-owner *current-thread*) (waitp 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))) - (/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) - (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) + "Acquire MUTEX for NEW-OWNER, which must be a thread or NIL. If +NEW-OWNER is NIL, it defaults to the current thread. If WAITP is +non-NIL and the mutex is in use, sleep until it is available. + +Note: using GET-MUTEX to assign a MUTEX to another thread then the +current one is not recommended, and liable to be deprecated. + +GET-MUTEX is not interrupt safe. The correct way to call it is: + + (WITHOUT-INTERRUPTS + ... + (ALLOW-WITH-INTERRUPTS (GET-MUTEX ...)) + ...) + +WITHOUT-INTERRUPTS is necessary to avoid an interrupt unwinding the +call while the mutex is in an inconsistent state while +ALLOW-WITH-INTERRUPTS allows the call to be interrupted from sleep. + +It is recommended that you use WITH-MUTEX instead of calling GET-MUTEX +directly." + (declare (type mutex mutex) (optimize (speed 3)) + #!-sb-thread (ignore waitp)) + (unless new-owner + (setq new-owner *current-thread*)) + (when (eql new-owner (mutex-%owner mutex)) + (error "Recursive lock attempt ~S." mutex)) #!+sb-thread (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*)) - ;; FIXME: sb-lutex and (not wait-p) + ;; FIXME: Lutexes do not currently support deadlines, as at least + ;; on Darwin pthread_foo_timedbar functions are not supported: + ;; this means that we probably need to use the Carbon multiprocessing + ;; functions on Darwin. + ;; + ;; FIXME: This is definitely not interrupt safe: what happens if + ;; we get hit (1) during the lutex calls (ok, they may be safe, + ;; but has that been checked?) (2) after the lutex call, but + ;; before setting the mutex owner. #!+sb-lutex - (when wait-p - (with-lutex-address (lutex (mutex-lutex mutex)) - (%lutex-lock lutex)) - (setf (mutex-value mutex) new-value)) + (when (zerop (with-lutex-address (lutex (mutex-lutex mutex)) + (if waitp + (with-interrupts (%lutex-lock lutex)) + (%lutex-trylock lutex)))) + (setf (mutex-%owner mutex) new-owner) + t) #!-sb-lutex - (let (old) - (loop - (unless - (setf old (sb!vm::%instance-set-conditional mutex 2 nil - new-value)) - (return t)) - (unless wait-p (return nil)) - (with-pinned-objects (mutex old) - (futex-wait (mutex-value-address mutex) - (sb!kernel:get-lisp-obj-address old))))))) + (let ((old (sb!ext:compare-and-swap (mutex-state mutex) + +lock-free+ + +lock-taken+))) + (unless (or (eql +lock-free+ old) (not waitp)) + (tagbody + :retry + (when (or (eql +lock-contested+ old) + (not (eql +lock-free+ + (sb!ext:compare-and-swap (mutex-state mutex) + +lock-taken+ + +lock-contested+)))) + ;; Wait on the contested lock. + (multiple-value-bind (to-sec to-usec) (decode-timeout nil) + (when (= 1 (with-pinned-objects (mutex) + (futex-wait (mutex-state-address mutex) + (get-lisp-obj-address +lock-contested+) + (or to-sec -1) + (or to-usec 0)))) + (signal-deadline)))) + (setf old (sb!ext:compare-and-swap (mutex-state mutex) + +lock-free+ + +lock-contested+)) + ;; Did we get it? + (unless (eql +lock-free+ old) + (go :retry)))) + (cond ((eql +lock-free+ old) + (let ((prev (sb!ext:compare-and-swap (mutex-%owner mutex) + nil new-owner))) + (when prev + (bug "Old owner in free mutex: ~S" prev)) + t)) + (waitp + (bug "Failed to acquire lock with WAITP.")))))) (defun release-mutex (mutex) #!+sb-doc "Release MUTEX by setting it to NIL. Wake up threads waiting for -this mutex." +this mutex. + +RELEASE-MUTEX is not interrupt safe: interrupts should be disabled +around calls to it. + +Signals a WARNING is current thread is not the current owner of the +mutex." (declare (type mutex mutex)) - (/show0 "Entering RELEASE-MUTEX") - (setf (mutex-value mutex) nil) + ;; Order matters: set owner to NIL before releasing state. + (let* ((self *current-thread*) + (old-owner (sb!ext:compare-and-swap (mutex-%owner mutex) self nil))) + (unless (eql self old-owner) + (warn "Releasing ~S, owned by another thread: ~S" mutex old-owner) + (setf (mutex-%owner mutex) nil))) #!+sb-thread (progn #!+sb-lutex (with-lutex-address (lutex (mutex-lutex mutex)) (%lutex-unlock lutex)) #!-sb-lutex - (futex-wake (mutex-value-address mutex) 1))) + (let ((old (sb!ext:compare-and-swap (mutex-state mutex) + +lock-taken+ +lock-free+))) + (when (eql old +lock-contested+) + (sb!ext:compare-and-swap (mutex-state mutex) + +lock-contested+ +lock-free+) + (with-pinned-objects (mutex) + (futex-wake (mutex-state-address mutex) 1)))) + nil)) ;;;; waitqueues/condition variables @@ -291,18 +370,13 @@ this mutex." (%make-waitqueue :name name)) #!+sb-doc -(setf (sb!kernel:fdocumentation 'waitqueue-name 'function) +(setf (fdocumentation 'waitqueue-name 'function) "The name of the waitqueue. Setfable.") #!+(and sb-thread (not sb-lutex)) -(progn - (declaim (inline waitqueue-data-address)) - (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))))) +(define-structure-slot-addressor waitqueue-data-address + :structure waitqueue + :slot data) (defun condition-wait (queue mutex) #!+sb-doc @@ -313,35 +387,50 @@ time we reacquire MUTEX and return to the caller." (assert mutex) #!-sb-thread (error "Not supported in unithread builds.") #!+sb-thread - (let ((value (mutex-value mutex))) + (let ((me *current-thread*)) + (assert (eq me (mutex-%owner 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)) + ;; Need to disable interrupts so that we don't miss setting the owner on + ;; our way out. (pthread_cond_wait handles the actual re-acquisition.) + (without-interrupts + (unwind-protect + (progn + (setf (mutex-%owner mutex) nil) + (with-lutex-address (queue-lutex-address (waitqueue-lutex queue)) + (with-lutex-address (mutex-lutex-address (mutex-lutex mutex)) + (with-local-interrupts + (%lutex-wait queue-lutex-address mutex-lutex-address))))) + (setf (mutex-%owner mutex) me))) #!-sb-lutex - (unwind-protect - (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 - (with-pinned-objects (queue me) - (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 mutex value)))) + ;; Need to disable interrupts so that we don't miss grabbing the mutex + ;; on our way out. + (without-interrupts + (unwind-protect + (let ((me *current-thread*)) + ;; FIXME: should we 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. We may get spurious wakeups, + ;; but that's ok. + (multiple-value-bind (to-sec to-usec) (decode-timeout nil) + (when (= 1 (with-pinned-objects (queue me) + (allow-with-interrupts + (futex-wait (waitqueue-data-address queue) + (get-lisp-obj-address me) + (or to-sec -1) ;; our way if saying "no timeout" + (or to-usec 0))))) + (signal-deadline)))) + ;; 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 mutex))))) (defun condition-notify (queue &optional (n 1)) #!+sb-doc @@ -379,41 +468,65 @@ time we reacquire MUTEX and return to the caller." ;;;; semaphores -(defstruct (semaphore (:constructor %make-semaphore)) +(defstruct (semaphore (:constructor %make-semaphore (name %count))) #!+sb-doc - "Semaphore type." + "Semaphore type. The fact that a SEMAPHORE is a STRUCTURE-OBJECT +should be considered an implementation detail, and may change in the +future." (name nil :type (or null simple-string)) - (count 0 :type (integer 0)) + (%count 0 :type (integer 0)) + (waitcount 0 :type (integer 0)) (mutex (make-mutex)) (queue (make-waitqueue))) +(setf (fdocumentation 'semaphore-name 'function) + "The name of the semaphore INSTANCE. Setfable.") + +(declaim (inline semaphore-count)) +(defun semaphore-count (instance) + "Returns the current count of the semaphore INSTANCE." + (semaphore-%count instance)) + (defun make-semaphore (&key name (count 0)) #!+sb-doc - "Create a semaphore with the supplied COUNT." - (%make-semaphore :name name :count count)) + "Create a semaphore with the supplied COUNT and NAME." + (%make-semaphore name count)) -(setf (sb!kernel:fdocumentation 'semaphore-name 'function) - "The name of the semaphore. Setfable.") - -(defun wait-on-semaphore (sem) +(defun wait-on-semaphore (semaphore) #!+sb-doc - "Decrement the count of SEM if the count would not be negative. Else -block until the semaphore can be decremented." - ;; a more direct implementation based directly on futexes should be - ;; possible - (with-mutex ((semaphore-mutex sem)) - (loop until (> (semaphore-count sem) 0) - do (condition-wait (semaphore-queue sem) (semaphore-mutex sem)) - finally (decf (semaphore-count sem))))) - -(defun signal-semaphore (sem &optional (n 1)) + "Decrement the count of SEMAPHORE if the count would not be +negative. Else blocks until the semaphore can be decremented." + ;; A more direct implementation based directly on futexes should be + ;; possible. + ;; + ;; We need to disable interrupts so that we don't forget to decrement the + ;; waitcount (which would happen if an asynch interrupt should catch us on + ;; our way out from the loop.) + (with-system-mutex ((semaphore-mutex semaphore) :allow-with-interrupts t) + ;; Quick check: is it positive? If not, enter the wait loop. + (let ((count (semaphore-%count semaphore))) + (if (plusp count) + (setf (semaphore-%count semaphore) (1- count)) + (unwind-protect + (progn + (incf (semaphore-waitcount semaphore)) + (loop until (plusp (setf count (semaphore-%count semaphore))) + do (condition-wait (semaphore-queue semaphore) (semaphore-mutex semaphore))) + (setf (semaphore-%count semaphore) (1- count))) + (decf (semaphore-waitcount semaphore))))))) + +(defun signal-semaphore (semaphore &optional (n 1)) #!+sb-doc - "Increment the count of SEM by N. If there are threads waiting on -this semaphore, then N of them is woken up." - (declare (type (and fixnum (integer 1)) n)) - (with-mutex ((semaphore-mutex sem)) - (when (= n (incf (semaphore-count sem) n)) - (condition-notify (semaphore-queue sem) n)))) + "Increment the count of SEMAPHORE by N. If there are threads waiting +on this semaphore, then N of them is woken up." + (declare (type (integer 1) n)) + ;; Need to disable interrupts so that we don't lose a wakeup after we have + ;; incremented the count. + (with-system-mutex ((semaphore-mutex semaphore)) + (let ((waitcount (semaphore-waitcount semaphore)) + (count (incf (semaphore-%count semaphore) n))) + (when (plusp waitcount) + (condition-notify (semaphore-queue semaphore) (min waitcount count)))))) ;;;; job control, independent listeners @@ -425,17 +538,21 @@ this semaphore, then N of them is woken up." (defvar *session* nil) -;;; the debugger itself tries to acquire the session lock, don't let +;;; The debugger itself tries to acquire the session lock, don't let ;;; funny situations (like getting a sigint while holding the session -;;; lock) occur +;;; lock) occur. At the same time we need to allow interrupts while +;;; *waiting* for the session lock for things like GET-FOREGROUND +;;; to be interruptible. +;;; +;;; Take care: we sometimes need to obtain the session lock while holding +;;; on to *ALL-THREADS-LOCK*, so we must _never_ obtain it _after_ getting +;;; a session lock! (Deadlock risk.) +;;; +;;; FIXME: It would be good to have ordered locks to ensure invariants like +;;; the above. (defmacro with-session-lock ((session) &body body) - #!-sb-thread (declare (ignore session)) - #!-sb-thread - `(locally ,@body) - #!+sb-thread - `(without-interrupts - (with-mutex ((session-lock ,session)) - ,@body))) + `(with-system-mutex ((session-lock ,session) :allow-with-interrupts t) + ,@body)) (defun new-session () (make-session :threads (list *current-thread*) @@ -467,16 +584,22 @@ this semaphore, then N of them is woken up." ;;; Remove thread from its session, if it has one. #!+sb-thread (defun handle-thread-exit (thread) - (with-mutex (*all-threads-lock*) - (/show0 "HANDLING THREAD EXIT") - #!+sb-lutex - (when (thread-interruptions-lock thread) - (/show0 "FREEING MUTEX LUTEX") - (with-lutex-address (lutex (mutex-lutex (thread-interruptions-lock thread))) - (%lutex-destroy lutex))) - (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 @@ -582,7 +705,8 @@ have the foreground next." (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 @@ -603,47 +727,50 @@ returns the thread exits." ;; 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) - (sb!kernel::*restart-clusters* nil) - (sb!kernel::*handler-clusters* nil) - (sb!kernel::*condition-restarts* nil) - ;; internal printer variables - (sb!impl::*previous-case* nil) - (sb!impl::*previous-readtable-case* nil) - (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 (*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 - "~~@" - *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) - (funcall real-function)) - ;; we're going down, can't handle - ;; interrupts sanely anymore - (let ((sb!impl::*gc-inhibit* t)) - (block-blockable-signals) - (setf (thread-%alive-p thread) nil) - (setf (thread-os-thread thread) nil) - ;; and remove what can be the last - ;; reference to this thread + (let* ((*current-thread* thread) + (*restart-clusters* nil) + (*handler-clusters* (sb!kernel::initial-handler-clusters)) + (*condition-restarts* nil) + (sb!impl::*deadline* nil) + (sb!impl::*step-out* nil) + ;; internal printer variables + (sb!impl::*previous-case* nil) + (sb!impl::*previous-readtable-case* nil) + (empty (vector)) + (sb!impl::*merge-sort-temp-vector* empty) + (sb!impl::*zap-array-data-temp* empty) + (sb!impl::*internal-symbol-output-fun* nil) + (sb!impl::*descriptor-handlers* nil)) ; serve-event + ;; Binding from C + (setf sb!vm:*alloc-signal* *default-alloc-signal*) + (setf (thread-os-thread thread) (current-thread-os-thread)) + (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 + "~~@" + *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) + (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 @@ -651,12 +778,38 @@ returns the thread exits." (with-pinned-objects (initial-function) (let ((os-thread (%create-thread - (sb!kernel:get-lisp-obj-address initial-function)))) + (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 "Deprecated. Same as TERMINATE-THREAD." @@ -671,15 +824,14 @@ returns the thread exits." (interrupt-thread-error-thread c))))) #!+sb-doc -(setf (sb!kernel:fdocumentation 'interrupt-thread-error-thread 'function) +(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))) + `(with-system-mutex ((thread-interruptions-lock ,thread)) + ,@body)) -;; Called from the signal handler. +;; Called from the signal handler in C. (defun run-interruption () (in-interruption () (loop @@ -705,13 +857,13 @@ 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) + (with-interrupt-bindings + (with-interrupts (funcall function))) #!+sb-thread (if (eq thread *current-thread*) - (funcall function) + (with-interrupt-bindings + (with-interrupts (funcall function))) (let ((os-thread (thread-os-thread thread))) (cond ((not os-thread) (error 'interrupt-thread-error :thread thread)) @@ -727,28 +879,73 @@ won't like the effect." 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 +(define-alien-routine "thread_yield" int) + +#!+sb-doc +(setf (fdocumentation 'thread-yield 'function) + "Yield the processor to other threads.") + +;;; internal use only. If you think you need to use these, 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 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) - (sb!kernel:make-lisp-obj tl-val)))) +(progn + (defun %thread-sap (thread) + (let ((thread-sap (alien-sap (extern-alien "all_threads" (* t)))) + (target (thread-os-thread thread))) + (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 target) (return thread-sap)) + (setf thread-sap + (sap-ref-sap thread-sap (* sb!vm:n-word-bytes + sb!vm::thread-next-slot))))))) + + (defun %symbol-value-in-thread (symbol thread) + (tagbody + ;; Prevent the dead from dying completely while we look for the TLS area... + (with-all-threads-lock + (if (thread-alive-p thread) + (let* ((offset (* sb!vm:n-word-bytes (sb!vm::symbol-tls-index symbol))) + (tl-val (sap-ref-word (%thread-sap thread) offset))) + (if (eql tl-val sb!vm::no-tls-value-marker-widetag) + (go :unbound) + (return-from %symbol-value-in-thread (values (make-lisp-obj tl-val) t)))) + (return-from %symbol-value-in-thread (values nil nil)))) + :unbound + (error "Cannot read thread-local symbol value: ~S unbound in ~S" symbol thread))) + + (defun %set-symbol-value-in-thread (symbol thread value) + (tagbody + (with-pinned-objects (value) + ;; Prevent the dead from dying completely while we look for the TLS area... + (with-all-threads-lock + (if (thread-alive-p thread) + (let* ((offset (* sb!vm:n-word-bytes (sb!vm::symbol-tls-index symbol))) + (sap (%thread-sap thread)) + (tl-val (sap-ref-word sap offset))) + (if (eql tl-val sb!vm::no-tls-value-marker-widetag) + (go :unbound) + (setf (sap-ref-word sap offset) (get-lisp-obj-address value))) + (return-from %set-symbol-value-in-thread (values value t))) + (return-from %set-symbol-value-in-thread (values nil nil))))) + :unbound + (error "Cannot set thread-local symbol value: ~S unbound in ~S" symbol thread)))) + +(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)))