X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=359b0f3c89255c3a1d5ed04617fd57d718d071d0;hb=f12b298a4ce9090470000360b49523e56475a680;hp=3884f95d8336918749ea12f091146688ee7cff2e;hpb=0d4c7a1323106c6e60511bef929048edcb040205;p=sbcl.git diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp index 3884f95..359b0f3 100644 --- a/src/code/target-thread.lisp +++ b/src/code/target-thread.lisp @@ -106,6 +106,11 @@ in future versions." ;;;; 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 @@ -115,9 +120,6 @@ in future versions." (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) @@ -218,10 +220,14 @@ in future versions." (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)) @@ -336,13 +342,16 @@ directly." +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+)) @@ -466,16 +475,19 @@ time we reacquire MUTEX and return to the caller." ;; 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 @@ -909,53 +921,54 @@ return DEFAULT if given or else signal JOIN-THREAD-ERROR." `(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