(in-package "SB!UNIX")
-;;; These should probably be somewhere, but I don't know where.
-(defconstant sig_dfl 0)
-(defconstant sig_ign 1)
+(defmacro with-interrupt-bindings (&body body)
+ (with-unique-names (empty)
+ `(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)
+ ;; Unless we do this, ADJUST-ARRAY and SORT would need to
+ ;; disable interrupts.
+ (,empty (vector))
+ (sb!impl::*zap-array-data-temp* ,empty)
+ (sb!impl::*merge-sort-temp-vector* ,empty))
+ ,@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
+ ;; 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))
+ (with-interrupt-bindings
+ (let ((sb!debug:*stack-top-hint*
+ (nth-value 1 (sb!kernel:find-interrupted-name-and-frame))))
+ (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."
+ `(dx-flet ((interruption () ,@body))
+ (invoke-interruption #'interruption)))
\f
;;;; system calls that deal with signals
+;;; Send the signal SIGNAL to the process with process id PID. SIGNAL
+;;; should be a valid signal number
#!-sb-fluid (declaim (inline real-unix-kill))
-(sb!alien:def-alien-routine ("kill" real-unix-kill) sb!c-call:int
- (pid sb!c-call:int)
- (signal sb!c-call:int))
-
-(defun unix-kill (pid signal)
- #!+sb-doc
- "Unix-kill sends the signal signal to the process with process
- id pid. Signal should be a valid signal number or a keyword of the
- standard UNIX signal name."
- (real-unix-kill pid (unix-signal-number signal)))
+(sb!alien:define-alien-routine ("kill" unix-kill) sb!alien:int
+ (pid sb!alien:int)
+ (signal sb!alien:int))
+;;; Send the signal SIGNAL to the all the process in process group
+;;; PGRP. SIGNAL should be a valid signal number
#!-sb-fluid (declaim (inline real-unix-killpg))
-(sb!alien:def-alien-routine ("killpg" real-unix-killpg) sb!c-call:int
- (pgrp sb!c-call:int)
- (signal sb!c-call:int))
-
-(defun unix-killpg (pgrp signal)
- #!+sb-doc
- "Unix-killpg sends the signal signal to the all the process in process
- group PGRP. Signal should be a valid signal number or a keyword of
- the standard UNIX signal name."
- (real-unix-killpg pgrp (unix-signal-number signal)))
-
-(sb!alien:def-alien-routine ("sigblock" unix-sigblock) sb!c-call:unsigned-long
- #!+sb-doc
- "Unix-sigblock cause the signals specified in mask to be
- added to the set of signals currently being blocked from
- delivery. The macro sigmask is provided to create masks."
- (mask sb!c-call:unsigned-long))
+(sb!alien:define-alien-routine ("killpg" unix-killpg) sb!alien:int
+ (pgrp sb!alien:int)
+ (signal sb!alien:int))
+
+;;; Reset the current set of masked signals (those being blocked from
+;;; delivery).
+;;;
+;;; (Note: CMU CL had a more general SIGSETMASK call and a SIGMASK
+;;; operator to create masks, but since we only ever reset to 0, we no
+;;; longer support it. If you need it, you can pull it out of the CMU
+;;; CL sources, or the old SBCL sources; but you might also consider
+;;; doing things the SBCL way and moving this kind of C-level work
+;;; down to C wrapper functions.)
+
+(sb!alien:define-alien-routine "unblock_deferrable_signals" sb!alien:void)
+(sb!alien:define-alien-routine "unblock_gc_signals" sb!alien:void)
-(sb!alien:def-alien-routine ("sigpause" unix-sigpause) sb!c-call:void
- #!+sb-doc
- "Unix-sigpause sets the set of masked signals to its argument
- and then waits for a signal to arrive, restoring the previous
- mask upon its return."
- (mask sb!c-call:unsigned-long))
-
-(sb!alien:def-alien-routine ("sigsetmask" unix-sigsetmask)
- sb!c-call:unsigned-long
- #!+sb-doc
- "Unix-sigsetmask sets the current set of masked signals (those
- begin blocked from delivery) to the argument. The macro sigmask
- can be used to create the mask. The previous value of the signal
- mask is returned."
- (mask sb!c-call:unsigned-long))
\f
;;;; C routines that actually do all the work of establishing signal handlers
-(sb!alien:def-alien-routine ("install_handler" install-handler)
- sb!c-call:unsigned-long
- (signal sb!c-call:int)
- (handler sb!c-call:unsigned-long))
-\f
+(sb!alien:define-alien-routine ("install_handler" install-handler)
+ sb!alien:unsigned-long
+ (signal sb!alien:int)
+ (handler sb!alien:unsigned-long))
+
;;;; interface to enabling and disabling signal handlers
(defun enable-interrupt (signal handler)
- (declare (type (or function (member :default :ignore)) handler))
- (without-gcing
- (let ((result (install-handler (unix-signal-number signal)
- (case handler
- (:default sig_dfl)
- (:ignore sig_ign)
- (t
- (sb!kernel:get-lisp-obj-address
- handler))))))
- (cond ((= result sig_dfl) :default)
- ((= result sig_ign) :ignore)
- (t (the function (sb!kernel:make-lisp-obj result)))))))
+ (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
+ (let ((result (install-handler signal
+ (case handler
+ (:default sig-dfl)
+ (:ignore sig-ign)
+ (t
+ (sb!kernel:get-lisp-obj-address
+ #'run-handler))))))
+ (cond ((= result sig-dfl) :default)
+ ((= result sig-ign) :ignore)
+ (t (the (or function fixnum)
+ (sb!kernel:make-lisp-obj result))))))))
(defun default-interrupt (signal)
(enable-interrupt signal :default))
;;;;
;;;; Most of these just call ERROR to report the presence of the signal.
+;;; SIGINT is handled like BREAK, except that ANSI BREAK ignores
+;;; *DEBUGGER-HOOK*, but we want SIGINT's BREAK to respect it, so that
+;;; SIGINT in --disable-debugger mode will cleanly terminate the system
+;;; (by respecting the *DEBUGGER-HOOK* established in that mode).
(eval-when (:compile-toplevel :execute)
- (sb!xc:defmacro define-signal-handler (name
- what
- &optional (function 'error))
+ (sb!xc:defmacro define-signal-handler (name what &optional (function 'error))
`(defun ,name (signal info context)
(declare (ignore signal info))
(declare (type system-area-pointer context))
- (/show "in Lisp-level signal handler" (sap-int context))
- (,function ,(concatenate 'simple-string what " at #X~X")
- (with-alien ((context (* os-context-t) context))
- (sap-int (sb!vm:context-pc context)))))))
+ (/show "in Lisp-level signal handler" ,(symbol-name name)
+ (sap-int context))
+ (with-interrupts
+ (,function ,(concatenate 'simple-string what " at #X~X")
+ (with-alien ((context (* os-context-t) context))
+ (sap-int (sb!vm:context-pc context))))))))
-(define-signal-handler sigint-handler "interrupted" break)
(define-signal-handler sigill-handler "illegal instruction")
-(define-signal-handler sigtrap-handler "breakpoint/trap")
-(define-signal-handler sigiot-handler "SIGIOT")
#!-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")
-(define-signal-handler sigpipe-handler "SIGPIPE")
-(define-signal-handler sigalrm-handler "SIGALRM")
-(defun sigquit-handler (signal code context)
+(defun sigint-handler (signal info context)
+ (declare (ignore signal info))
+ (declare (type system-area-pointer context))
+ (/show "in Lisp-level SIGINT handler" (sap-int context))
+ (flet ((interrupt-it ()
+ (with-alien ((context (* os-context-t) context))
+ (with-interrupts
+ (%break 'sigint 'interactive-interrupt
+ :context context
+ :address (sap-int (sb!vm:context-pc context)))))))
+ (sb!thread:interrupt-thread (sb!thread::foreground-thread)
+ #'interrupt-it)))
+
+(defun sigalrm-handler (signal info context)
+ (declare (ignore signal info context))
+ (declare (type system-area-pointer context))
+ (sb!impl::run-expired-timers))
+
+(defun sigterm-handler (signal code context)
(declare (ignore signal code context))
- (throw 'sb!impl::top-level-catcher nil))
+ (sb!thread::terminate-session)
+ (sb!ext:quit))
+
+;;; 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))
(defun sb!kernel:signal-cold-init-or-reinit ()
#!+sb-doc
"Enable all the default signals that Lisp knows how to deal with."
- (enable-interrupt :sigint #'sigint-handler)
- (enable-interrupt :sigquit #'sigquit-handler)
- (enable-interrupt :sigill #'sigill-handler)
- (enable-interrupt :sigtrap #'sigtrap-handler)
- (enable-interrupt :sigiot #'sigiot-handler)
+ (enable-interrupt sigint #'sigint-handler)
+ (enable-interrupt sigterm #'sigterm-handler)
+ (enable-interrupt sigill #'sigill-handler)
#!-linux
- (enable-interrupt :sigemt #'sigemt-handler)
- (enable-interrupt :sigfpe #'sb!vm:sigfpe-handler)
- (enable-interrupt :sigbus #'sigbus-handler)
- (enable-interrupt :sigsegv #'sigsegv-handler)
+ (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)
- (enable-interrupt :sigpipe #'sigpipe-handler)
- (enable-interrupt :sigalrm #'sigalrm-handler)
- nil)
+ (enable-interrupt sigsys #'sigsys-handler)
+ (enable-interrupt sigalrm #'sigalrm-handler)
+ (enable-interrupt sigpipe #'sigpipe-handler)
+ #!+hpux (ignore-interrupt sigxcpu)
+ (unblock-gc-signals)
+ (unblock-deferrable-signals)
+ (values))
\f
-;;; stale code which I'm insufficiently motivated to test -- WHN 19990714
-#|
-;;;; WITH-ENABLED-INTERRUPTS
+;;;; etc.
-(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)))))))
-|#
+;;; extract si_code from siginfo_t
+(sb!alien:define-alien-routine ("siginfo_code" siginfo-code) sb!alien:int
+ (info system-area-pointer))
+
+;;; CMU CL comment:
+;;; Magically converted by the compiler into a break instruction.
+(defun receive-pending-interrupt ()
+ (receive-pending-interrupt))