X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=62c7b03612ccc621d51c41b9be2dd8f4861ce413;hb=15d6e7c9a2c3234f95dfe278046fa2fee1b0c007;hp=59e96adaa0e1c3833dccb9f00bf9a4511357f0b5;hpb=9c0fdf35270405ee8384d7f6a5a4b641d5df33c4;p=sbcl.git diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp index 59e96ad..62c7b03 100644 --- a/src/code/target-thread.lisp +++ b/src/code/target-thread.lisp @@ -1,96 +1,31 @@ +;;;; support for threads in the target machine + +;;;; 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") ;;; FIXME it would be good to define what a thread id is or isn't (our ;;; current assumption is that it's a fixnum). It so happens that on ;;; Linux it's a pid, but it might not be on posix thread implementations -(sb!alien::define-alien-routine ("create_thread" %create-thread) - sb!alien:unsigned-long - (lisp-fun-address sb!alien:unsigned-long)) - -(sb!alien::define-alien-routine "signal_thread_to_dequeue" - sb!alien:unsigned-int - (thread-pid sb!alien:unsigned-long)) - -(defvar *session* nil) +(define-alien-routine ("create_thread" %create-thread) + unsigned-long + (lisp-fun-address unsigned-long)) -(defun make-thread (function) - (let* ((real-function (coerce function 'function)) - (tid - (%create-thread - (sb!kernel:get-lisp-obj-address - (lambda () - ;; in time we'll move some of the binding presently done in C - ;; here too - (let ((sb!kernel::*restart-clusters* nil) - (sb!impl::*descriptor-handlers* nil) ; serve-event - (sb!impl::*available-buffers* nil)) ;for fd-stream - ;; can't use handling-end-of-the-world, because that flushes - ;; output streams, and we don't necessarily have any (or we - ;; could be sharing them) - (sb!sys:enable-interrupt sb!unix:sigint :ignore) - (sb!unix:unix-exit - (catch 'sb!impl::%end-of-the-world - (with-simple-restart - (destroy-thread - (format nil "~~@" - (current-thread-id))) - (funcall real-function)) - 0)))))))) - (with-mutex ((session-lock *session*)) - (pushnew tid (session-threads *session*))) - tid)) - -;;; Really, you don't want to use these: they'll get into trouble with -;;; garbage collection. Use a lock or a waitqueue instead -(defun suspend-thread (thread-id) - (sb!unix:unix-kill thread-id sb!unix:sigstop)) -(defun resume-thread (thread-id) - (sb!unix:unix-kill thread-id sb!unix:sigcont)) -;;; Note warning about cleanup forms -(defun destroy-thread (thread-id) - "Destroy the thread identified by THREAD-ID abruptly, without running cleanup forms" - (sb!unix:unix-kill thread-id sb!unix:sigterm) - ;; may have been stopped for some reason, so now wake it up to - ;; deliver the TERM - (sb!unix:unix-kill thread-id sb!unix:sigcont)) +(define-alien-routine "signal_thread_to_dequeue" + unsigned-int + (thread-id unsigned-long)) +(define-alien-routine reap-dead-threads void) -;;; a moderate degree of care is expected for use of interrupt-thread, -;;; due to its nature: if you interrupt a thread that was holding -;;; important locks then do something that turns out to need those -;;; locks, you probably won't like the effect. Used with thought -;;; though, it's a good deal gentler than the last-resort functions above - -(defun interrupt-thread (thread function) - "Interrupt THREAD and make it run FUNCTION. " - (sb!unix::syscall* ("interrupt_thread" - sb!alien:unsigned-long sb!alien:unsigned-long) - thread - thread (sb!kernel:get-lisp-obj-address - (coerce function 'function)))) -(defun terminate-thread (thread-id) - "Terminate the thread identified by THREAD-ID, by causing it to run -SB-EXT:QUIT - the usual cleanup forms will be evaluated" - (interrupt-thread thread-id 'sb!ext:quit)) - -(declaim (inline current-thread-id)) -(defun current-thread-id () - (logand - (sb!sys:sap-int - (sb!vm::current-thread-offset-sap sb!vm::thread-pid-slot)) - ;; KLUDGE pids are 16 bit really. Avoid boxing the return value - (1- (ash 1 16)))) - -;;;; iterate over the in-memory threads - -(defun mapcar-threads (function) - "Call FUNCTION once for each known thread, giving it the thread structure as argument" - (let ((function (coerce function 'function))) - (loop for thread = (alien-sap (extern-alien "all_threads" (* t))) - then (sb!sys:sap-ref-sap thread (* 4 sb!vm::thread-next-slot)) - until (sb!sys:sap= thread (sb!sys:int-sap 0)) - collect (funcall function thread)))) +(defvar *session* nil) ;;;; queues, locks @@ -158,6 +93,7 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" (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) @@ -187,6 +123,9 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" ;;; 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)) + "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))) (unless new-value (setf new-value pid)) @@ -210,7 +149,8 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" (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)) @@ -232,16 +172,6 @@ SB-EXT:QUIT - the usual cleanup forms will be evaluated" (setf (mutex-value lock) nil) (futex-wake (mutex-value-address lock) 1)) - -(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 (defun condition-wait (queue lock) @@ -318,13 +248,134 @@ time we reacquire LOCK and return to the caller." (defun maybe-install-futex-functions () #!+sb-futex (unless (zerop (extern-alien "linux_supports_futex" int)) - (setf (fdefinition 'get-mutex) #'get-mutex/futex - (fdefinition 'release-mutex) #'release-mutex/futex - (fdefinition 'condition-wait) #'condition-wait/futex - (fdefinition 'condition-broadcast) #'condition-broadcast/futex - (fdefinition 'condition-notify) #'condition-notify/futex) + (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 + (%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!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) + (catch 'sb!impl::%end-of-the-world + (with-simple-restart + (destroy-thread + (format nil "~~@" + (current-thread-id))) + (funcall real-function)) + 0)) + (values)))))) + (with-mutex ((session-lock *session*)) + (pushnew tid (session-threads *session*))) + tid)) + +;;; Really, you don't want to use these: they'll get into trouble with +;;; garbage collection. Use a lock or a waitqueue instead +(defun suspend-thread (thread-id) + (sb!unix:unix-kill thread-id sb!unix:sigstop)) +(defun resume-thread (thread-id) + (sb!unix:unix-kill thread-id sb!unix:sigcont)) +;;; Note warning about cleanup forms +(defun destroy-thread (thread-id) + "Destroy the thread identified by THREAD-ID abruptly, without running cleanup forms" + (sb!unix:unix-kill thread-id sb!unix:sigterm) + ;; may have been stopped for some reason, so now wake it up to + ;; deliver the TERM + (sb!unix:unix-kill thread-id sb!unix:sigcont)) + + + + +;;; a moderate degree of care is expected for use of interrupt-thread, +;;; due to its nature: if you interrupt a thread that was holding +;;; important locks then do something that turns out to need those +;;; locks, you probably won't like the effect. Used with thought +;;; though, it's a good deal gentler than the last-resort functions above + +(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) + (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 +SB-EXT:QUIT - the usual cleanup forms will be evaluated" + (interrupt-thread thread-id 'sb!ext:quit)) + +(declaim (inline current-thread-id)) +(defun current-thread-id () + (logand + (sb!sys:sap-int + (sb!vm::current-thread-offset-sap sb!vm::thread-pid-slot)) + ;; KLUDGE pids are 16 bit really. Avoid boxing the return value + (1- (ash 1 16)))) + +;;;; iterate over the in-memory threads + +(defun mapcar-threads (function) + "Call FUNCTION once for each known thread, giving it the thread structure as argument" + (let ((function (coerce function 'function))) + (loop for thread = (alien-sap (extern-alien "all_threads" (* t))) + then (sb!sys:sap-ref-sap thread (* 4 sb!vm::thread-next-slot)) + until (sb!sys:sap= thread (sb!sys:int-sap 0)) + collect (funcall function thread)))) + +(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 (* 4 sb!vm::thread-pid-slot)))) + (when (= pid id) (return thread)) + (setf thread (sb!sys:sap-ref-sap thread (* 4 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-32 thread (* 4 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 @@ -341,15 +392,16 @@ time we reacquire LOCK and return to the caller." (defun init-job-control () (setf *session* (new-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) - (let ((tid (current-thread-id))) - (with-mutex ((session-lock *session*)) - (setf (session-threads *session*) - (delete tid (session-threads *session*)) - (session-interactive-threads *session*) - (delete tid (session-interactive-threads *session*)))) - (let ((*session* (new-session))) - (funcall fn)))) + (%delete-thread-from-session (current-thread-id) *session*) + (let ((*session* (new-session))) (funcall fn))) (defmacro with-new-session (args &body forms) (declare (ignore args)) ;for extensibility @@ -357,9 +409,18 @@ time we reacquire LOCK and return to the caller." `(labels ((,fb-name () ,@forms)) (call-with-new-session (function ,fb-name))))) +;;; 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) + (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*)) @@ -374,39 +435,39 @@ thread is not the foreground thread" (defun debugger-wait-until-foreground-thread (stream) "Returns T if thread had been running in background, NIL if it was interactive." + (declare (ignore stream)) (prog1 (with-mutex ((session-lock *session*)) (not (member (current-thread-id) (session-interactive-threads *session*)))) (get-foreground))) -(defun thread-repl-prompt-fun (out-stream) - (get-foreground) - (let ((stopped-threads (cdr (session-interactive-threads *session*)))) - (when stopped-threads - (format out-stream "~{~&Thread ~A suspended~}~%" stopped-threads)) - (sb!impl::repl-prompt-fun out-stream))) (defun get-foreground () - (loop - (with-mutex ((session-lock *session*)) - (let ((tid (current-thread-id))) - (when (eql (car (session-interactive-threads *session*)) tid) - (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler) - (return-from get-foreground t)) - (unless (member tid *interactive-threads*) - (setf (cdr (last (session-interactive-threads *session*))) - (list tid))) - (condition-wait - (session-interactive-threads-queue *session*) - (session-lock *session*)))))) + (let ((was-foreground t)) + (loop + (with-mutex ((session-lock *session*)) + (let ((tid (current-thread-id)) + (int-t (session-interactive-threads *session*))) + (when (eql (car int-t) tid) + (unless was-foreground + (format *query-io* "Resuming thread ~A~%" tid)) + (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler) + (return-from get-foreground t)) + (setf was-foreground nil) + (unless (member tid int-t) + (setf (cdr (last int-t)) + (list tid))) + (condition-wait + (session-interactive-threads-queue *session*) + (session-lock *session*))))))) (defun release-foreground (&optional next) "Background this thread. If NEXT is supplied, arrange for it to have the foreground next" (with-mutex ((session-lock *session*)) (let ((tid (current-thread-id))) (setf (session-interactive-threads *session*) - (delete tid *interactive-threads*)) + (delete tid (session-interactive-threads *session*))) (sb!sys:enable-interrupt sb!unix:sigint :ignore) (when next (setf (session-interactive-threads *session*)