X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-signal.lisp;h=feea1cf7faeb9ccfeda403e324764059d9285b33;hb=ad096f09fb631331f584121bfe5ee3bfc7f1f951;hp=7125c737c9715814dcc22d914e254f007a398532;hpb=a7409fa0a69f733ea2460a1aeddbe04b5c4c0888;p=sbcl.git diff --git a/src/code/target-signal.lisp b/src/code/target-signal.lisp index 7125c73..feea1cf 100644 --- a/src/code/target-signal.lisp +++ b/src/code/target-signal.lisp @@ -11,30 +11,61 @@ (in-package "SB!UNIX") +(defmacro with-interrupt-bindings (&body body) + `(let* + ;; KLUDGE: Whatever is on the PCL stacks before the interrupt + ;; handler runs doesn't really matter, since we're not on the + ;; same call stack, really -- and if we don't bind these (esp. + ;; the cache one) we can get a bogus metacircle if an interrupt + ;; handler calls a GF that was being computed when the interrupt + ;; hit. + ((sb!pcl::*cache-miss-values-stack* nil) + (sb!pcl::*dfun-miss-gfs-on-stack* nil)) + ,@body)) + +;;; Evaluate CLEANUP-FORMS iff PROTECTED-FORM does a non-local exit. +(defmacro nlx-protect (protected-form &rest cleanup-froms) + (with-unique-names (completep) + `(let ((,completep nil)) + (without-interrupts + (unwind-protect + (progn + (allow-with-interrupts + ,protected-form) + (setq ,completep t)) + (unless ,completep + ,@cleanup-froms)))))) + (defun invoke-interruption (function) (without-interrupts - ;; FIXME: This is wrong. Imagine the following sequence: - ;; - ;; 1. an asynch interrupt arrives after entry to - ;; WITHOUT-INTERRUPTS but before RESET-SIGNAL-MASK: pending - ;; machinery blocks all signals and marks the signal as - ;; pending. - ;; - ;; 2. RESET-SIGNAL-MASK is called, and all signals are unblocked. - ;; - ;; 3. Another signal arrives while we already have one pending. - ;; Oops -- we lose(). - ;; - ;; Not sure what the right thing is, but definitely not - ;; RESET-SIGNAL-MASK. Removing it breaks signals.impure.lisp - ;; right now, though, and this is a rare race, so... - (reset-signal-mask) - (funcall function))) - -(defmacro in-interruption ((&rest args) &body body) + ;; Reset signal mask: the C-side handler has blocked all + ;; deferrable signals before funcalling into lisp. They are to be + ;; unblocked the first time interrupts are enabled. With this + ;; mechanism there are no extra frames on the stack from a + ;; previous signal handler when the next signal is delivered + ;; provided there is no WITH-INTERRUPTS. + (let ((*unblock-deferrables-on-enabling-interrupts-p* t) + (sb!debug:*stack-top-hint* (or sb!debug:*stack-top-hint* 'invoke-interruption))) + (with-interrupt-bindings + (sb!thread::without-thread-waiting-for (:already-without-interrupts t) + (allow-with-interrupts + (nlx-protect (funcall function) + ;; We've been running with deferrables + ;; blocked in Lisp called by a C signal + ;; handler. If we return normally the sigmask + ;; in the interrupted context is restored. + ;; However, if we do an nlx the operating + ;; system will not restore it for us. + (when *unblock-deferrables-on-enabling-interrupts-p* + ;; This means that storms of interrupts + ;; doing an nlx can still run out of stack. + (unblock-deferrable-signals))))))))) + +(defmacro in-interruption ((&key) &body body) #!+sb-doc "Convenience macro on top of INVOKE-INTERRUPTION." - `(invoke-interruption (lambda () ,@body) ,@args)) + `(dx-flet ((interruption () ,@body)) + (invoke-interruption #'interruption))) ;;;; system calls that deal with signals @@ -62,9 +93,24 @@ ;;; doing things the SBCL way and moving this kind of C-level work ;;; down to C wrapper functions.) -;;; When inappropriate build options are used, this also prints messages -;;; listing the signals that were masked -(sb!alien:define-alien-routine "reset_signal_mask" sb!alien:void) +(declaim (inline %unblock-deferrable-signals %unblock-gc-signals)) +(sb!alien:define-alien-routine ("unblock_deferrable_signals" + %unblock-deferrable-signals) + sb!alien:void + (where sb!alien:unsigned-long) + (old sb!alien:unsigned-long)) +#!-sb-safepoint +(sb!alien:define-alien-routine ("unblock_gc_signals" %unblock-gc-signals) + sb!alien:void + (where sb!alien:unsigned-long) + (old sb!alien:unsigned-long)) + +(defun unblock-deferrable-signals () + (%unblock-deferrable-signals 0 0)) + +#!-sb-safepoint +(defun unblock-gc-signals () + (%unblock-gc-signals 0 0)) ;;;; C routines that actually do all the work of establishing signal handlers @@ -79,6 +125,7 @@ (declare (type (or function fixnum (member :default :ignore)) handler)) (/show0 "enable-interrupt") (flet ((run-handler (&rest args) + (declare (truly-dynamic-extent args)) (in-interruption () (apply handler args)))) (without-gcing @@ -124,7 +171,6 @@ #!-linux (define-signal-handler sigemt-handler "SIGEMT") (define-signal-handler sigbus-handler "bus error") -(define-signal-handler sigsegv-handler "segmentation violation") #!-linux (define-signal-handler sigsys-handler "bad argument to a system call") @@ -134,12 +180,18 @@ (/show "in Lisp-level SIGINT handler" (sap-int context)) (flet ((interrupt-it () (with-alien ((context (* os-context-t) context)) - (%break 'sigint 'interactive-interrupt - :context context - :address (sap-int (sb!vm:context-pc context)))))) + (with-interrupts + (let ((int (make-condition 'interactive-interrupt + :context context + :address (sap-int (sb!vm:context-pc context))))) + ;; First SIGNAL, so that handlers can run. + (signal int) + ;; Then enter the debugger like BREAK. + (%break 'sigint int)))))) (sb!thread:interrupt-thread (sb!thread::foreground-thread) #'interrupt-it))) +#!-sb-wtimer (defun sigalrm-handler (signal info context) (declare (ignore signal info context)) (declare (type system-area-pointer context)) @@ -147,13 +199,22 @@ (defun sigterm-handler (signal code context) (declare (ignore signal code context)) - (sb!thread::terminate-session) - (sb!ext:quit)) + (sb!ext:exit)) + +#!-sb-thruption +;;; SIGPIPE is not used in SBCL for its original purpose, instead it's +;;; for signalling a thread that it should look at its interruption +;;; queue. The handler (RUN_INTERRUPTION) just returns if there is +;;; nothing to do so it's safe to receive spurious SIGPIPEs coming +;;; from the kernel. +(defun sigpipe-handler (signal code context) + (declare (ignore signal code context)) + (sb!thread::run-interruption)) -;; Also known as SIGABRT. -(defun sigiot-handler (signal code context) +;;; the handler for SIGCHLD signals for RUN-PROGRAM +(defun sigchld-handler (signal code context) (declare (ignore signal code context)) - (sb!impl::%halt)) + (sb!impl::get-processes-status-changes)) (defun sb!kernel:signal-cold-init-or-reinit () #!+sb-doc @@ -161,17 +222,20 @@ (enable-interrupt sigint #'sigint-handler) (enable-interrupt sigterm #'sigterm-handler) (enable-interrupt sigill #'sigill-handler) - (enable-interrupt sigiot #'sigiot-handler) #!-linux (enable-interrupt sigemt #'sigemt-handler) (enable-interrupt sigfpe #'sb!vm:sigfpe-handler) (enable-interrupt sigbus #'sigbus-handler) - (enable-interrupt sigsegv #'sigsegv-handler) #!-linux (enable-interrupt sigsys #'sigsys-handler) - (ignore-interrupt sigpipe) + #!-sb-wtimer (enable-interrupt sigalrm #'sigalrm-handler) - (sb!unix::reset-signal-mask) + #!-sb-thruption + (enable-interrupt sigpipe #'sigpipe-handler) + (enable-interrupt sigchld #'sigchld-handler) + #!+hpux (ignore-interrupt sigxcpu) + #!-sb-safepoint (unblock-gc-signals) + (unblock-deferrable-signals) (values)) ;;;; etc. @@ -184,31 +248,3 @@ ;;; Magically converted by the compiler into a break instruction. (defun receive-pending-interrupt () (receive-pending-interrupt)) - -;;; stale code which I'm insufficiently motivated to test -- WHN 19990714 -#| -;;;; WITH-ENABLED-INTERRUPTS - -(defmacro with-enabled-interrupts (interrupt-list &body body) - #!+sb-doc - "With-enabled-interrupts ({(interrupt function)}*) {form}* - Establish function as a handler for the Unix signal interrupt which - should be a number between 1 and 31 inclusive." - (let ((il (gensym)) - (it (gensym))) - `(let ((,il NIL)) - (unwind-protect - (progn - ,@(do* ((item interrupt-list (cdr item)) - (intr (caar item) (caar item)) - (ifcn (cadar item) (cadar item)) - (forms NIL)) - ((null item) (nreverse forms)) - (when (symbolp intr) - (setq intr (symbol-value intr))) - (push `(push `(,,intr ,(enable-interrupt ,intr ,ifcn)) ,il) - forms)) - ,@body) - (dolist (,it (nreverse ,il)) - (enable-interrupt (car ,it) (cadr ,it))))))) -|#