;;;; Aliens, low level stuff
+(define-alien-routine "kill_safely"
+ integer
+ (os-thread #!-alpha unsigned-long #!+alpha unsigned-int)
+ (signal int))
+
#!+sb-thread
(progn
;; FIXME it would be good to define what a thread id is or isn't
(define-alien-routine ("create_thread" %create-thread)
unsigned-long (lisp-fun-address unsigned-long))
- (define-alien-routine "signal_interrupt_thread"
- integer (os-thread unsigned-long))
-
(define-alien-routine "block_deferrable_signals"
void)
(if (and (not *interrupts-enabled*) *allow-with-interrupts*)
;; If interrupts are disabled, 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))
+ ;; in a while. %CHECK-INTERRUPTS is taking shortcuts, make
+ ;; sure that deferrables are unblocked by doing an empty
+ ;; WITH-INTERRUPTS once.
+ (progn
+ (with-interrupts)
+ (loop
+ (loop repeat 128 do (cas)) ; 128 is arbitrary here
+ (sb!unix::%check-interrupts)))
(loop (cas)))))
t))
+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))))
+ (loop
+ (multiple-value-bind (to-sec to-usec) (decode-timeout nil)
+ (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))
+ ((2))
+ (otherwise (return))))))
(setf old (sb!ext:compare-and-swap (mutex-state mutex)
+lock-free+
+lock-contested+))
;; 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)
- ;; our way if saying "no
- ;; timeout":
- (or to-sec -1)
- (or to-usec 0)))))
- (signal-deadline))))
+ (loop
+ (multiple-value-bind (to-sec to-usec) (decode-timeout nil)
+ (case (with-pinned-objects (queue me)
+ (allow-with-interrupts
+ (futex-wait (waitqueue-data-address queue)
+ (get-lisp-obj-address me)
+ ;; our way if saying "no
+ ;; timeout":
+ (or to-sec -1)
+ (or to-usec 0))))
+ ((1) (signal-deadline))
+ ((2))
+ (otherwise (return))))))
;; 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
`(with-system-mutex ((thread-interruptions-lock ,thread))
,@body))
-;;; Called from the signal handler in C.
+;;; Called from the signal handler.
+#!-win32
(defun run-interruption ()
- (in-interruption ()
- (loop
- (let ((interruption (with-interruptions-lock (*current-thread*)
- (pop (thread-interruptions *current-thread*)))))
- ;; Resignalling after popping one works fine, because from the
- ;; OS's point of view we have returned from the signal handler
- ;; (thanks to arrange_return_to_lisp_function) so at least one
- ;; more signal will be delivered.
- (when (thread-interruptions *current-thread*)
- (signal-interrupt-thread (thread-os-thread *current-thread*)))
- (if interruption
- (with-interrupts
- (funcall interruption))
- (return))))))
-
-;;; The order of interrupt execution is peculiar. If thread A
-;;; interrupts thread B with I1, I2 and B for some reason receives I1
-;;; when FUN2 is already on the list, then it is FUN2 that gets to run
-;;; first. But when FUN2 is run SIG_INTERRUPT_THREAD is enabled again
-;;; and I2 hits pretty soon in FUN2 and run FUN1. This is of course
-;;; just one scenario, and the order of thread interrupt execution is
-;;; undefined.
+ (let ((interruption (with-interruptions-lock (*current-thread*)
+ (pop (thread-interruptions *current-thread*)))))
+ ;; If there is more to do, then resignal and let the normal
+ ;; interrupt deferral mechanism take care of the rest. From the
+ ;; OS's point of view the signal we are in the handler for is no
+ ;; longer pending, so the signal will not be lost.
+ (when (thread-interruptions *current-thread*)
+ (kill-safely (thread-os-thread *current-thread*) sb!unix:sigpipe))
+ (when interruption
+ (funcall interruption))))
+
(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))
- #!-sb-thread
+won't like the effect. FUNCTION runs with interrupts disabled, but
+WITH-INTERRUPTS is allowed in it. Keep in mind that many things may
+enable interrupts (GET-MUTEX when contended, for instance) so the
+first thing to do is usually a WITH-INTERRUPTS or a
+WITHOUT-INTERRUPTS. Within a thread interrupts are queued, they are
+run in same the order they were sent."
+ #!+win32
+ (declare (ignore thread))
+ #!+win32
(with-interrupt-bindings
(with-interrupts (funcall function)))
- #!+sb-thread
- (if (eq thread *current-thread*)
- (with-interrupt-bindings
- (with-interrupts (funcall function)))
- (let ((os-thread (thread-os-thread thread)))
- (cond ((not os-thread)
- (error 'interrupt-thread-error :thread thread))
- (t
- (with-interruptions-lock (thread)
- (push function (thread-interruptions thread)))
- (when (minusp (signal-interrupt-thread os-thread))
- (error 'interrupt-thread-error :thread thread)))))))
+ #!-win32
+ (let ((os-thread (thread-os-thread thread)))
+ (cond ((not os-thread)
+ (error 'interrupt-thread-error :thread thread))
+ (t
+ (with-interruptions-lock (thread)
+ ;; Append to the end of the interruptions queue. It's
+ ;; O(N), but it does not hurt to slow interruptors down a
+ ;; bit when the queue gets long.
+ (setf (thread-interruptions thread)
+ (append (thread-interruptions thread)
+ (list (lambda ()
+ (without-interrupts
+ (allow-with-interrupts
+ (funcall function))))))))
+ (when (minusp (kill-safely os-thread sb!unix:sigpipe))
+ (error 'interrupt-thread-error :thread thread))))))
(defun terminate-thread (thread)
#!+sb-doc
projects / sbcl.git / blobdiff