X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=8723a7f984006de10cefef758d458b26cefed377;hb=344a1f088581303c92da333ddddc9aeb9c212ba9;hp=2e5edfac226269e46baa2aeec88541d0f42779bb;hpb=ba9112b2f0ba10230be5bdfc75c8e082da9bfbe0;p=sbcl.git diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp index 2e5edfa..8723a7f 100644 --- a/src/code/target-thread.lisp +++ b/src/code/target-thread.lisp @@ -59,17 +59,9 @@ offending thread using THREAD-ERROR-THREAD.")) to be joined. The offending thread can be accessed using THREAD-ERROR-THREAD.")) -(defun join-thread-error-thread (condition) +(define-deprecated-function :late "1.0.29.17" join-thread-error-thread thread-error-thread + (condition) (thread-error-thread condition)) -(define-compiler-macro join-thread-error-thread (condition) - (deprecation-warning 'join-thread-error-thread 'thread-error-thread) - `(thread-error-thread ,condition)) - -#!+sb-doc -(setf - (fdocumentation 'join-thread-error-thread 'function) - "The thread that we failed to join. Deprecated, use THREAD-ERROR-THREAD -instead.") (define-condition interrupt-thread-error (thread-error) () (:report (lambda (c s) @@ -80,17 +72,9 @@ instead.") "Signalled when interrupting a thread fails because the thread has already exited. The offending thread can be accessed using THREAD-ERROR-THREAD.")) -(defun interrupt-thread-error-thread (condition) +(define-deprecated-function :late "1.0.29.17" interrupt-thread-error-thread thread-error-thread + (condition) (thread-error-thread condition)) -(define-compiler-macro interrupt-thread-error-thread (condition) - (deprecation-warning 'join-thread-error-thread 'thread-error-thread) - `(thread-error-thread ,condition)) - -#!+sb-doc -(setf - (fdocumentation 'interrupt-thread-error-thread 'function) - "The thread that was not interrupted. Deprecated, use THREAD-ERROR-THREAD -instead.") ;;; Of the WITH-PINNED-OBJECTS in this file, not every single one is ;;; necessary because threads are only supported with the conservative @@ -325,7 +309,12 @@ created and old ones may exit at any time." ;; FIXME: this does not work on SMP Pentium Pro and OOSTORE systems, ;; neither on most non-x86 architectures (but we don't have threads ;; on those). - (setf (spinlock-value spinlock) nil)) + (setf (spinlock-value spinlock) nil) + + ;; FIXME: Is a :memory barrier too strong here? Can we use a :write + ;; barrier instead? + #!+(not (or x86 x86-64)) + (barrier (:memory))) ;;;; Mutexes @@ -356,32 +345,15 @@ HOLDING-MUTEX-P." ;; Make sure to get the current value. (sb!ext:compare-and-swap (mutex-%owner mutex) nil nil)) -(defun get-mutex (mutex &optional (new-owner *current-thread*) (waitp t)) +(defun get-mutex (mutex &optional (new-owner *current-thread*) + (waitp t) (timeout nil)) #!+sb-doc - "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." + "Deprecated in favor of GRAB-MUTEX." (declare (type mutex mutex) (optimize (speed 3)) - #!-sb-thread (ignore waitp)) + #!-sb-thread (ignore waitp timeout)) (unless new-owner (setq new-owner *current-thread*)) + (barrier (:read)) (let ((old (mutex-%owner mutex))) (when (eq new-owner old) (error "Recursive lock attempt ~S." mutex)) @@ -402,12 +374,16 @@ directly." ;; but has that been checked?) (2) after the lutex call, but ;; before setting the mutex owner. #!+sb-lutex - (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) + (progn + (when timeout + (error "Mutex timeouts not supported on this platform.")) + (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) + (barrier (:write)) + t)) #!-sb-lutex ;; This is a direct translation of the Mutex 2 algorithm from ;; "Futexes are Tricky" by Ulrich Drepper. @@ -424,13 +400,17 @@ directly." +lock-contested+)))) ;; Wait on the contested lock. (loop - (multiple-value-bind (to-sec to-usec) (decode-timeout nil) + (multiple-value-bind (to-sec to-usec stop-sec stop-usec deadlinep) + (decode-timeout timeout) + (declare (ignore stop-sec stop-usec)) (case (with-pinned-objects (mutex) (futex-wait (mutex-state-address mutex) (get-lisp-obj-address +lock-contested+) (or to-sec -1) (or to-usec 0))) - ((1) (signal-deadline)) + ((1) (if deadlinep + (signal-deadline) + (return-from get-mutex nil))) ((2)) (otherwise (return)))))) (setf old (sb!ext:compare-and-swap (mutex-state mutex) @@ -448,6 +428,47 @@ directly." (waitp (bug "Failed to acquire lock with WAITP.")))))) +(defun grab-mutex (mutex &key (waitp t) (timeout nil)) + #!+sb-doc + "Acquire MUTEX for the current thread. If WAITP is true (the default) and +the mutex is not immediately available, sleep until it is available. + +If TIMEOUT is given, it specifies a relative timeout, in seconds, on +how long GRAB-MUTEX should try to acquire the lock in the contested +case. Unsupported on :SB-LUTEX platforms (eg. Darwin), where a non-NIL +TIMEOUT signals an error. + +If GRAB-MUTEX returns T, the lock acquisition was successful. In case +of WAITP being NIL, or an expired TIMEOUT, GRAB-MUTEX may also return +NIL which denotes that GRAB-MUTEX did -not- acquire the lock. + +Notes: + + - GRAB-MUTEX is not interrupt safe. The correct way to call it is: + + (WITHOUT-INTERRUPTS + ... + (ALLOW-WITH-INTERRUPTS (GRAB-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. + + - (GRAB-MUTEX :timeout 0.0) differs from + (GRAB-MUTEX :waitp nil) in that the former may signal a + DEADLINE-TIMEOUT if the global deadline was due already on + entering GRAB-MUTEX. + + The exact interplay of GRAB-MUTEX and deadlines are reserved to + change in future versions. + + - It is recommended that you use WITH-MUTEX instead of calling + GRAB-MUTEX directly. +" + (get-mutex mutex nil waitp timeout)) + (defun release-mutex (mutex &key (if-not-owner :punt)) #!+sb-doc "Release MUTEX by setting it to NIL. Wake up threads waiting for @@ -500,11 +521,15 @@ IF-NOT-OWNER is :FORCE)." (defstruct (waitqueue (:constructor %make-waitqueue)) #!+sb-doc "Waitqueue type." - (name nil :type (or null simple-string)) + (name nil :type (or null thread-name)) #!+(and sb-lutex sb-thread) (lutex (make-lutex)) #!-sb-lutex - (data nil)) + (token nil)) + +(def!method print-object ((waitqueue waitqueue) stream) + (print-unreadable-object (waitqueue stream :type t :identity t) + (format stream "~@[~A~]" (waitqueue-name waitqueue)))) (defun make-waitqueue (&key name) #!+sb-doc @@ -516,23 +541,45 @@ IF-NOT-OWNER is :FORCE)." "The name of the waitqueue. Setfable.") #!+(and sb-thread (not sb-lutex)) -(define-structure-slot-addressor waitqueue-data-address +(define-structure-slot-addressor waitqueue-token-address :structure waitqueue - :slot data) + :slot token) (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 MUTEX and return to the caller. - -Note that if CONDITION-WAIT unwinds (due to eg. a timeout) instead of + "Atomically release MUTEX and enqueue ourselves on QUEUE. Another thread may +subsequently notify us using CONDITION-NOTIFY, at which time we reacquire +MUTEX and return to the caller. + +Important: CONDITION-WAIT may return without CONDITION-NOTIFY having occurred. +The correct way to write code that uses CONDITION-WAIT is to loop around the +call, checking the the associated data: + + (defvar *data* nil) + (defvar *queue* (make-waitqueue)) + (defvar *lock* (make-mutex)) + + ;; Consumer + (defun pop-data () + (with-mutex (*lock*) + (loop until *data* + do (condition-wait *queue* *lock*)) + (pop *data*))) + + ;; Producer + (defun push-data (data) + (with-mutex (*lock*) + (push data *data*) + (condition-notify *queue*))) + +Also note that if CONDITION-WAIT unwinds (due to eg. a timeout) instead of returning normally, it may do so without holding the mutex." #!-sb-thread (declare (ignore queue)) (assert mutex) #!-sb-thread (error "Not supported in unithread builds.") #!+sb-thread (let ((me *current-thread*)) + (barrier (:read)) (assert (eq me (mutex-%owner mutex))) (/show0 "CONDITION-WAITing") #!+sb-lutex @@ -547,56 +594,58 @@ returning normally, it may do so without holding the mutex." (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))) + (barrier (:write) + (setf (mutex-%owner mutex) me)))) #!-sb-lutex ;; Need to disable interrupts so that we don't miss grabbing the ;; mutex on our way out. (without-interrupts - (let ((me nil)) - ;; This setf becomes visible to other CPUS due to the usual - ;; memory barrier semantics of lock acquire/release. This must - ;; not be moved into the loop else wakeups may be lost upon - ;; continuing after a deadline or EINTR. - (setf (waitqueue-data queue) me) - (loop - (multiple-value-bind (to-sec to-usec) - (allow-with-interrupts (decode-timeout nil)) - (case (unwind-protect - (with-pinned-objects (queue me) - ;; RELEASE-MUTEX is purposefully as close to - ;; FUTEX-WAIT as possible to reduce the size - ;; of the window where WAITQUEUE-DATA may be - ;; set by a notifier. - (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. - (allow-with-interrupts - (futex-wait (waitqueue-data-address queue) - (get-lisp-obj-address me) - ;; our way of saying "no - ;; timeout": - (or to-sec -1) - (or to-usec 0)))) - ;; 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. - (allow-with-interrupts (get-mutex mutex))) - ;; ETIMEDOUT; we know it was a timeout, yet we cannot - ;; signal a deadline unconditionally here because the - ;; call to GET-MUTEX may already have signaled it. - ((1)) - ;; EINTR - ((2)) - ;; EWOULDBLOCK, -1 here, is the possible spurious wakeup - ;; case. 0 is the normal wakeup. - (otherwise (return))))))))) + ;; This setf becomes visible to other CPUS due to the usual + ;; memory barrier semantics of lock acquire/release. This must + ;; not be moved into the loop else wakeups may be lost upon + ;; continuing after a deadline or EINTR. + (setf (waitqueue-token queue) me) + (loop + (multiple-value-bind (to-sec to-usec) + (allow-with-interrupts (decode-timeout nil)) + (case (unwind-protect + (with-pinned-objects (queue me) + ;; RELEASE-MUTEX is purposefully as close to + ;; FUTEX-WAIT as possible to reduce the size of + ;; the window where the token may be set by a + ;; notifier. + (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 the token, and so futex-wait + ;; returns immediately instead of sleeping. + ;; Ergo, no lost wakeup. We may get spurious + ;; wakeups, but that's ok. + (allow-with-interrupts + (futex-wait (waitqueue-token-address queue) + (get-lisp-obj-address me) + ;; our way of saying "no + ;; timeout": + (or to-sec -1) + (or to-usec 0)))) + ;; 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. + (allow-with-interrupts (get-mutex mutex))) + ;; ETIMEDOUT; we know it was a timeout, yet we cannot + ;; signal a deadline unconditionally here because the + ;; call to GET-MUTEX may already have signaled it. + ((1)) + ;; EINTR; we do not need to return to the caller because + ;; an interleaved wakeup would change the token causing an + ;; EWOULDBLOCK in the next iteration. + ((2)) + ;; EWOULDBLOCK, -1 here, is the possible spurious wakeup + ;; case. 0 is the normal wakeup. + (otherwise (return)))))))) (defun condition-notify (queue &optional (n 1)) #!+sb-doc @@ -613,17 +662,19 @@ this call." #!+sb-lutex (with-lutex-address (lutex (waitqueue-lutex queue)) (%lutex-wake lutex n)) - ;; no problem if >1 thread notifies during the comment in - ;; condition-wait: as long as the value in queue-data isn't the - ;; waiting thread's id, it matters not what it is + ;; 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 -- using the queue object itself is handy. + ;; ;; XXX we should do something to ensure that the result of this setf - ;; is visible to all CPUs + ;; is visible to all CPUs. + ;; + ;; ^-- surely futex_wake() involves a memory barrier? #!-sb-lutex - (let ((me *current-thread*)) - (progn - (setf (waitqueue-data queue) me) - (with-pinned-objects (queue) - (futex-wake (waitqueue-data-address queue) n)))))) + (progn + (setf (waitqueue-token queue) queue) + (with-pinned-objects (queue) + (futex-wake (waitqueue-token-address queue) n))))) (defun condition-broadcast (queue) #!+sb-doc @@ -642,8 +693,8 @@ this call." "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)) + (name nil :type (or null thread-name)) + (%count 0 :type (integer 0)) (waitcount 0 :type sb!vm:word) (mutex (make-mutex)) (queue (make-waitqueue))) @@ -1145,7 +1196,24 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" (setf (sap-ref-word (%thread-sap thread) offset) (get-lisp-obj-address value)) (values value :ok)))) - (values nil :thread-dead)))))) + (values nil :thread-dead))))) + + (define-alien-variable tls-index-start unsigned-int) + + ;; Get values from the TLS. + (defun %thread-local-values (thread) + (without-gcing + (when (thread-alive-p thread) + (let ((sap (%thread-sap thread))) + (loop for index from tls-index-start below + (symbol-value 'sb!vm::*free-tls-index*) + for value = (sap-ref-word sap (* sb!vm:n-word-bytes index)) + for obj = (sb!kernel:make-lisp-obj value nil) + unless (or (typep obj '(or boolean fixnum character)) + (member value + '(#.sb!vm:no-tls-value-marker-widetag + #.sb!vm:unbound-marker-widetag))) + collect obj)))))) (defun symbol-value-in-thread (symbol thread &optional (errorp t)) "Return the local value of SYMBOL in THREAD, and a secondary value of T