X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=fe34aacbe8afbe379993e3123b89d369dd867ef5;hb=10adbe19b88bf9d4fe65ad67f6de0fd065af87ff;hp=8678534b61fd06536d682d36c631b3c5876f9a6c;hpb=6bb7ec8c220863904aebfbee95fb13805ef1f4e7;p=sbcl.git diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp index 8678534..fe34aac 100644 --- a/src/code/target-thread.lisp +++ b/src/code/target-thread.lisp @@ -23,6 +23,8 @@ unsigned-int (thread-id unsigned-long)) +(define-alien-routine reap-dead-threads void) + (defvar *session* nil) ;;;; queues, locks @@ -56,7 +58,7 @@ (declaim (inline waitqueue-data-address mutex-value-address)) (defstruct waitqueue - (name nil :type (or null simple-base-string)) + (name nil :type (or null simple-string)) (lock 0) (data nil)) @@ -82,69 +84,25 @@ (sb!alien:define-alien-routine "block_sigcont" void) (sb!alien:define-alien-routine "unblock_sigcont_and_sleep" void) -#!+sb-futex (declaim (inline futex-wait futex-wake)) -#!+sb-futex (sb!alien:define-alien-routine "futex_wait" int (word unsigned-long) (old-value unsigned-long)) -#!+sb-futex (sb!alien:define-alien-routine "futex_wake" int (word unsigned-long) (n unsigned-long)) -;;; this should only be called while holding the queue spinlock. -;;; it releases the spinlock before sleeping -(defun wait-on-queue (queue &optional lock) - (let ((pid (current-thread-id))) - (block-sigcont) - (when lock (release-mutex lock)) - (sb!sys:without-interrupts - (pushnew pid (waitqueue-data queue))) - (setf (waitqueue-lock queue) 0) - (unblock-sigcont-and-sleep))) - -;;; this should only be called while holding the queue spinlock. It doesn't -;;; release it -(defun dequeue (queue) - (let ((pid (current-thread-id))) - (sb!sys:without-interrupts - (setf (waitqueue-data queue) - (delete pid (waitqueue-data queue)))))) - -;;; this should only be called while holding the queue spinlock. -(defun signal-queue-head (queue) - (let ((p (car (waitqueue-data queue)))) - (when p (signal-thread-to-dequeue p)))) - ;;;; mutex -;;; i suspect there may be a race still in this: the futex version requires -;;; the old mutex value before sleeping, so how do we get away without it (defun get-mutex (lock &optional new-value (wait-p t)) - (declare (type mutex lock) (optimize (speed 3))) - (let ((pid (current-thread-id))) - (unless new-value (setf new-value pid)) - (assert (not (eql new-value (mutex-value lock)))) - (get-spinlock lock 2 pid) - (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) - (return t)) - (unless wait-p - (setf (waitqueue-lock lock) 0) - (return nil)) - (wait-on-queue lock nil)))) - -#!+sb-futex -(defun get-mutex/futex (lock &optional new-value (wait-p t)) + "Acquire LOCK, setting it to NEW-VALUE or some suitable default value +if NIL. If WAIT-P is non-NIL and the lock is in use, sleep until it +is available" (declare (type mutex lock) (optimize (speed 3))) (let ((pid (current-thread-id)) old) (unless new-value (setf new-value pid)) - (assert (not (eql new-value (mutex-value lock)))) + (when (eql new-value (mutex-value lock)) + (warn "recursive lock attempt ~S~%" lock)) (loop (unless (setf old (sb!vm::%instance-set-conditional lock 4 nil new-value)) @@ -153,15 +111,7 @@ (futex-wait (mutex-value-address lock) (sb!kernel:get-lisp-obj-address old))))) -(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))) - -#!+sb-futex -(defun release-mutex/futex (lock) +(defun release-mutex (lock) (declare (type mutex lock)) (setf (mutex-value lock) nil) (futex-wake (mutex-value-address lock) 1)) @@ -175,22 +125,6 @@ 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 @@ -212,11 +146,6 @@ time we reacquire LOCK and return to the caller." (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 @@ -226,30 +155,11 @@ time we reacquire LOCK and return to the caller." (setf (waitqueue-data queue) me) (futex-wake (waitqueue-data-address queue) 1))) -#!+sb-futex -(defun condition-broadcast/futex (queue) +(defun condition-broadcast (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)) - (sb!ext:without-package-locks - (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 @@ -259,20 +169,23 @@ time we reacquire LOCK and return to the caller." ;; in time we'll move some of the binding presently done in C ;; here too (let ((sb!kernel::*restart-clusters* nil) + (sb!kernel::*handler-clusters* nil) + (sb!kernel::*condition-restarts* 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 "~~@" - (current-thread-id))) - (funcall real-function)) - 0)))))))) + (catch 'sb!impl::%end-of-the-world + (with-simple-restart + (destroy-thread + (format nil "~~@" + (current-thread-id))) + (funcall real-function)) + 0)) + (values)))))) + (when (zerop tid) (error "Can't create a new thread")) (with-mutex ((session-lock *session*)) (pushnew tid (session-threads *session*))) tid)) @@ -300,15 +213,29 @@ time we reacquire LOCK and return to the caller." ;;; locks, you probably won't like the effect. Used with thought ;;; though, it's a good deal gentler than the last-resort functions above +(define-condition interrupt-thread-error (error) + ((thread :reader interrupt-thread-error-thread :initarg :thread) + (errno :reader interrupt-thread-error-errno :initarg :errno)) + (: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)))))) + (defun interrupt-thread (thread function) "Interrupt THREAD and make it run FUNCTION." (let ((function (coerce function 'function))) - (sb!sys:with-pinned-objects (function) - (sb!unix::syscall* ("interrupt_thread" - sb!alien:unsigned-long sb!alien:unsigned-long) - thread - thread - (sb!kernel:get-lisp-obj-address function))))) + (sb!sys:with-pinned-objects + (function) + (multiple-value-bind (res err) + (sb!unix::syscall ("interrupt_thread" + sb!alien:unsigned-long sb!alien:unsigned-long) + thread + thread + (sb!kernel:get-lisp-obj-address function)) + (unless res + (error 'interrupt-thread-error :thread thread :errno err)))))) + (defun terminate-thread (thread-id) "Terminate the thread identified by THREAD-ID, by causing it to run @@ -329,10 +256,35 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" "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)) + then (sb!sys:sap-ref-sap thread (* sb!vm:n-word-bytes + sb!vm::thread-next-slot)) until (sb!sys:sap= thread (sb!sys:int-sap 0)) collect (funcall function thread)))) +(defun thread-sap-from-id (id) + (let ((thread (alien-sap (extern-alien "all_threads" (* t))))) + (loop + (when (sb!sys:sap= thread (sb!sys:int-sap 0)) (return nil)) + (let ((pid (sb!sys:sap-ref-32 thread (* sb!vm:n-word-bytes + sb!vm::thread-pid-slot)))) + (when (= pid id) (return thread)) + (setf thread (sb!sys:sap-ref-sap thread (* sb!vm:n-word-bytes + sb!vm::thread-next-slot))))))) + +;;; 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 +(defun symbol-value-in-thread (symbol thread-id) + (let ((thread (thread-sap-from-id thread-id))) + (when thread + (let* ((index (sb!vm::symbol-tls-index symbol)) + (tl-val (sb!sys:sap-ref-word thread + (* 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)))))) + ;;;; job control, independent listeners (defstruct session @@ -349,15 +301,15 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" (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 %delete-thread-from-session (tid session) + (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)) + (%delete-thread-from-session (current-thread-id) *session*) (let ((*session* (new-session))) (funcall fn))) (defmacro with-new-session (args &body forms) @@ -366,14 +318,18 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" `(labels ((,fb-name () ,@forms)) (call-with-new-session (function ,fb-name))))) -;;; this is called from a C signal handler: some signals may be masked +;;; Remove thread id TID from its session, if it has one. This is +;;; called from C reap_dead_threads() so is run in the context of +;;; whichever thread called that (usually after a GC), which may not have +;;; any meaningful parent/child/sibling relationship with the dead thread (defun handle-thread-exit (tid) - "Remove thread id TID from the session, if it's there" - (%delete-thread-from-session tid)) + (let ((session (symbol-value-in-thread '*session* tid))) + (and session (%delete-thread-from-session tid session)))) (defun terminate-session () - "Kill all threads in session exept for this one. Does nothing if current + "Kill all threads in session except for this one. Does nothing if current thread is not the foreground thread" + (reap-dead-threads) (let* ((tid (current-thread-id)) (to-kill (with-mutex ((session-lock *session*))