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Commit 14fc8fb4 authored by ram's avatar ram
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;;; -*- Package: Extensions; Log: code.log -*-
;;;
;;; **********************************************************************
;;; This code was written as part of the Spice Lisp project at
;;; Carnegie-Mellon University, and has been placed in the public domain.
;;; If you want to use this code or any part of Spice Lisp, please contact
;;; Scott Fahlman (FAHLMAN@CMUC).
;;; **********************************************************************
;;;
;;; RUN-PROGRAM and friends. Factilty for running unix programs from inside
;;; a lisp.
;;;
;;; Written by Jim Healy and Bill Chiles, November 1987, using an earlier
;;; version written by David McDonald.
;;;
;;; Completely re-written by William Lott, July 1989 - January 1990.
;;;
(in-package "EXTENSIONS")
(export '(run-program process-status process-exit-code process-core-dumped
process-wait process-kill process-input process-output process-plist
process-pty process-error process-status-hook process-alive-p
process-close process-pid process-p))
;;;; Import WAIT3 from unix.
(ext:def-c-pointer *wait (unsigned-byte 32))
(ext:def-c-routine ("wait3" c-wait3)
(int)
(status *wait :out)
(options int)
(rusage int))
(eval-when (load eval compile)
(defconstant wait-wstopped #o177)
(defconstant wait-wnohang 1)
(defconstant wait-wuntraced 2))
(defun wait3 (&optional do-not-hang check-for-stopped)
"Return any available status information on child processed. "
(multiple-value-bind (pid status)
(c-wait3 (logior (if do-not-hang
wait-wnohang
0)
(if check-for-stopped
wait-wuntraced
0))
0)
(cond ((or (minusp pid)
(zerop pid))
nil)
((eql (ldb (byte 8 0) status)
wait-wstopped)
(values pid
:stopped
(ldb (byte 8 8) status)))
((zerop (ldb (byte 7 0) status))
(values pid
:exited
(ldb (byte 8 8) status)))
(t
(let ((signal (ldb (byte 7 0) status)))
(values pid
(if (or (eql signal mach:sigstop)
(eql signal mach:sigtstp)
(eql signal mach:sigttin)
(eql signal mach:sigttou))
:stopped
:signaled)
signal
(not (zerop (ldb (byte 1 7) status)))))))))
;;;; Process control stuff.
(defvar *active-processes* nil
"List of process structures for all active processes.")
(defstruct (process (:print-function %print-process))
pid ; PID of child process.
%status ; Either :RUNNING, :STOPPED, :EXITED, or :SIGNALED.
exit-code ; Either exit code or signal
core-dumped ; T if a core image was dumped.
pty ; Stream to child's pty or nil.
input ; Stream to child's input or nil.
output ; Stream from child's output or nil.
error ; Stream from child's error output or nil.
status-hook ; Closure to call when PROC changes status.
plist ; Place for clients to stash tings.
)
(defun %print-process (proc stream depth)
(declare (ignore depth))
(format stream "#<process ~D ~S>"
(process-pid proc)
(process-status proc)))
;;; PROCESS-STATUS -- Public.
;;;
(defun process-status (proc)
"Return the current status of process. The result is one of :running,
:stopped, :exited, :signaled."
(get-processes-status-changes)
(process-%status proc))
;;; PROCESS-WAIT -- Public.
;;;
(defun process-wait (proc &optional check-for-stopped)
"Wait for PROC to quit running for some reason. Returns PROC."
(loop
(unless (or (eq (process-status proc) :running)
(and check-for-stopped
(eq (process-status proc) :stopped)))
(return))
(system:serve-all-events 1))
proc)
;;; FIND-CURRENT-FOREGROUND-PROCESS -- internal
;;;
;;; Finds the current foreground process group id.
;;;
(defun find-current-foreground-process (proc)
(mach:with-trap-arg-block mach::int1 pgrp
(multiple-value-bind
(wonp error)
(mach:unix-ioctl (system:fd-stream-fd (ext:process-pty proc))
mach:TIOCGPGRP
(lisp::alien-value-sap mach::int1))
(unless wonp
(error "TIOCPGRP ioctl failed: ~S"
(mach:get-unix-error-msg error)))
(system:alien-access (mach::int1-int (system:alien-value pgrp))))))
;;; PROCESS-KILL -- public
;;;
;;; Hand a process a signal.
;;;
(defun process-kill (proc signal &optional (whom :pid))
"Hand SIGNAL to PROC. If whom is :pid, use the kill Unix system call. If
whom is :process-group, use the killpg Unix system call. If whom is
:pty-process-group deliver the signal to whichever process group is currently
in the foreground."
(let ((pid (ecase whom
((:pid :process-group)
(process-pid proc))
(:pty-process-group
(find-current-foreground-process proc)))))
(multiple-value-bind (okay errno)
(if (eq whom :pty-process-group)
(mach:unix-killpg pid signal)
(mach:unix-kill pid signal))
(cond ((not okay)
(values nil errno))
((and (eql pid (process-pid proc))
(= (unix-signal-number signal) mach:sigcont))
(setf (process-%status proc) :running)
(setf (process-exit-code proc) nil)
(when (process-status-hook proc)
(funcall (process-status-hook proc) proc))
t)
(t
t)))))
;;; PROCESS-ALIVE-P -- public
;;;
;;; Returns T if the process is still alive, NIL otherwise.
;;;
(defun process-alive-p (proc)
"Returns T if the process is still alive, NIL otherwise."
(let ((status (process-status proc)))
(if (or (eq status :running)
(eq status :stopped))
t
nil)))
;;; PROCESS-CLOSE -- public
;;;
;;; Close all the streams held open by PROC.
;;;
(defun process-close (proc)
"Close all streams connected to PROC and stop maintaining the status slot."
(macrolet ((frob (stream)
`(when ,stream (close ,stream))))
(frob (process-pty proc))
(frob (process-input proc))
(frob (process-output proc))
(frob (process-error proc))
(system:without-interrupts
(setf *active-processes* (delete proc *active-processes*)))
proc))
;;; SIGCHLD-HANDLER -- Internal.
;;;
;;; This should be the handler for sigchld signals that RUN-PROGRAM establishes.
;;;
;;; Since interrupts are so broken in the current RT system, we don't turn on
;;; sigchld signals for now. We call this by hand whenever we need to check
;;; the status of a process.
;;;
(defun sigchld-handler (ignore1 ignore2 ignore3)
(declare (ignore ignore1 ignore2 ignore3))
(get-processes-status-changes))
;;; GET-PROCESSES-STATUS-CHANGES -- Internal.
;;;
(defun get-processes-status-changes ()
(loop
(multiple-value-bind (pid what code core)
(wait3 t t)
(unless pid
(return))
(let ((proc (find pid *active-processes* :key #'process-pid)))
(when proc
(setf (process-%status proc) what)
(setf (process-exit-code proc) code)
(setf (process-core-dumped proc) core)
(when (process-status-hook proc)
(funcall (process-status-hook proc) proc))
(when (or (eq what :exited)
(eq what :signaled))
(system:without-interrupts
(setf *active-processes*
(delete proc *active-processes*)))))))))
;;;; RUN-PROGRAM and close friends.
(defvar *close-on-error* nil
"List of file descriptors to close when RUN-PROGRAM exits due to an error.")
(defvar *close-in-parent* nil
"List of file descriptors to close when RUN-PROGRAM returns in the parent.")
(defvar *handlers-installed* nil
"List of handlers installed by RUN-PROGRAM.")
;;; FIND-A-PTY -- internal
;;;
;;; Finds a pty that is not in use. Returns three values: the file descriptor
;;; for the master side of the pty, the file descriptor for the slave side of
;;; the pty, and the name of the tty device for the slave side.
;;;
(defun find-a-pty ()
"Returns the master fd, the slave fd, and the name of the tty"
(dolist (char '(#\p #\q))
(dotimes (digit 16)
(let* ((master-name (format nil "/dev/pty~C~X" char digit))
(master-fd (mach:unix-open master-name
mach:o_rdwr
#o666)))
(when master-fd
(let* ((slave-name (format nil "/dev/tty~C~X" char digit))
(slave-fd (mach:unix-open slave-name
mach:o_rdwr
#o666)))
(when slave-fd
; Maybe put a vhangup here?
(mach:unix-ioctl slave-fd
mach:TIOCGETP
(system:alien-sap mach:sgtty))
(setf (system:alien-access (mach::sgtty-flags mach:sgtty))
#o6300) ; XTABS|EVENP|ODDP
(mach:unix-ioctl slave-fd
mach:TIOCSETP
(system:alien-sap mach:sgtty))
(mach:unix-ioctl master-fd
mach:TIOCGETP
(system:alien-sap mach:sgtty))
(setf (system:alien-access (mach::sgtty-flags mach:sgtty))
(logand (system:alien-access (mach::sgtty-flags mach:sgtty))
(lognot 8))) ; ~ECHO
(mach:unix-ioctl master-fd
mach:TIOCSETP
(system:alien-sap mach:sgtty))
(return-from find-a-pty
(values master-fd
slave-fd
slave-name))))
(mach:unix-close master-fd)))))
(error "Could not find a pty."))
;;; OPEN-PTY -- internal
;;;
(defun open-pty (pty)
(when pty
(multiple-value-bind
(master slave name)
(find-a-pty)
(push master *close-on-error*)
(push slave *close-in-parent*)
(when (streamp pty)
(multiple-value-bind (won new-fd) (mach:unix-dup master)
(unless won
(error "Could not MACH:UNIX-DUP ~D: ~A"
master (mach:get-unix-error-msg new-fd)))
(push new-fd *close-on-error*)
(copy-descriptor-to-stream new-fd pty)))
(values name
(system:make-fd-stream master :input t :output t)))))
;;; SETUP-CHILD -- internal
;;;
;;; Execs the program after setting up the environment correctly. This
;;; routine never returns under any condition.
;;;
(defun setup-child (pfile args env stdin stdout stderr pty-name before-execve)
(unwind-protect
(handler-bind ((error #'(lambda (condition)
(declare (ignore condition))
(mach:unix-exit 2))))
;; Put us in our own pgrp.
(mach:unix-setpgrp 0 (mach:unix-getpid))
;; If we want a pty, set it up.
(when pty-name
(let ((old-tty (mach:unix-open "/dev/tty" mach:o_rdwr 0)))
(when old-tty
(mach:unix-ioctl old-tty mach:TIOCNOTTY 0)
(mach:unix-close old-tty)))
(let ((new-tty (mach:unix-open pty-name mach:o_rdwr 0)))
(when new-tty
(mach:unix-dup2 new-tty 0)
(mach:unix-dup2 new-tty 1)
(mach:unix-dup2 new-tty 2))))
;; Setup the three standard descriptors.
(when stdin
(mach:unix-dup2 stdin 0))
(when stdout
(mach:unix-dup2 stdout 1))
(when stderr
(mach:unix-dup2 stderr 2))
;; Close all other descriptors.
(do ((fd (1- (mach:unix-getdtablesize))
(1- fd)))
((= fd 3))
(mach:unix-close fd))
;; Do the before-execve
(when before-execve
(funcall before-execve))
;; Exec the program
(mach:unix-execve pfile args env))
;; If exec returns, we lose.
(mach:unix-exit 1)))
;;; RUN-PROGRAM -- public
;;;
;;; RUN-PROGRAM uses fork and execve to run a different program. Strange stuff
;;; happens to keep the unix state of the world coherent.
;;;
;;; The child process needs to get it's input from somewhere, and send it's
;;; output (both standard and error) to somewhere. We have to do different
;;; things depending on where these somewheres really are.
;;;
;;; For input, there are five options:
;;; - T: Just leave fd 0 alone. Pretty simple.
;;; - "file": Read from the file. We need to open the file and pull the
;;; descriptor out of the stream. The parent should close this stream after
;;; the child is up and running to free any storage used in the parent.
;;; - NIL: Same as "file", but use "/dev/null" as the file.
;;; - :STREAM: Use unix-pipe to create two descriptors. Use system:make-fd-stream
;;; to create the output stream on the writeable descriptor, and pass the
;;; readable descriptor to the child. The parent must close the readable
;;; descriptor for EOF to be passed up correctly.
;;; - a stream: If it's a fd-stream, just pull the descriptor out of it.
;;; Otherwise make a pipe as in :STREAM, and copy everything across.
;;;
;;; For output, there are n options:
;;; - T: Leave descriptor 1 alone.
;;; - "file": dump output to the file.
;;; - NIL: dump output to /dev/null.
;;; - :STREAM: return a stream that can be read from.
;;; - a stream: if it's a fd-stream, use the descriptor in it. Otherwise, copy
;;; stuff from output to stream.
;;;
;;; For error, there are all the same options as output plus:
;;; - :OUTPUT: redirect to the same place as output.
;;;
;;; RUN-PROGRAM returns a process struct for the process if the fork worked,
;;; and NIL if it did not.
;;;
(defun run-program (program args
&key (env *environment-list*) (wait t) pty input
if-input-does-not-exist output (if-output-exists :error)
(error :output) (if-error-exists :error) status-hook
before-execve)
"Run-program creates a new process and runs the unix progam in the
file specified by the simple-string program. Args are the standard
arguments that can be passed to a Unix program, for no arguments
use NIL (which means just the name of the program is passed as arg 0).
Run program will either return NIL or a PROCESS structure. See the CMU
Common Lisp Users Manual for details about the PROCESS structure.
The keyword arguments have the following meanings:
:env -
An A-LIST mapping keyword environment variables to simple-string
values.
:wait -
If non-NIL (default), wait until the created process finishes. If
NIL, continue running Lisp until the program finishes.
:pty -
Either T, NIL, or a stream. Unless NIL, the subprocess is established
under a PTY. If :pty is a stream, all output to this pty is sent to
this stream, otherwise the PROCESS-PTY slot is filled in with a stream
connected to pty that can read output and write input.
:input -
Either T, NIL, a pathname, a stream, or :STREAM. If T, the standard
input for the current process is inherited. If NIL, /dev/null
is used. If a pathname, the file so spesified is used. If a stream,
all the input is read from that stream and send to the subprocess. If
:STREAM, the PROCESS-INPUT slot is filled in with a stream that sends
its output to the process. Defaults to NIL.
:if-input-does-not-exist (when :input is the name of a file) -
can be one of:
:error - generate an error.
:create - create an empty file.
nil (default) - return nil from run-program.
:output -
Either T, NIL, a pathname, a stream, or :STREAM. If T, the standard
input for the current process is inherited. If NIL, /dev/null
is used. If a pathname, the file so spesified is used. If a stream,
all the output from the process is written to this stream. If
:STREAM, the PROCESS-OUTPUT slot is filled in with a stream that can
be read to get the output. Defaults to NIL.
:if-output-exists (when :input is the name of a file) -
can be one of:
:error (default) - generates an error if the file already exists.
:supersede - output from the program supersedes the file.
:append - output from the program is appended to the file.
nil - run-program returns nil without doing anything.
:error and :if-error-exists -
Same as :output and :if-output-exists, except that :error can also be
spesified as :output in which case all error output is routed to the
same place as normal output.
:status-hook -
This is a function the system calls whenever the status of the
process changes. The function takes the process as an argument.
:before-execve -
This is a function, without arguments, RUN-PROGRAM runs in the child
process just before turning it into the specified program."
;; Make sure the interrupt handler is installed.
;(system:enable-interrupt mach:sigchld #'sigchld-handler)
;; Make sure all the args are okay.
(unless (every #'simple-string-p args)
(error "All args to program must be simple strings -- ~S." args))
;; Pre-pend the program to the argument list.
(push (namestring program) args)
;; Clear random specials used by GET-DESCRIPTOR-FOR to communicate cleanup
;; info. Also, establish proc at this level so we can return it.
(let (*close-on-error* *close-in-parent* *handlers-installed* proc)
(unwind-protect
(let ((pfile (namestring (truename (merge-pathnames program "path:")))))
(multiple-value-bind
(stdin input-stream)
(get-descriptor-for input :direction :input
:if-does-not-exist if-input-does-not-exist)
(multiple-value-bind
(stdout output-stream)
(get-descriptor-for output :direction :output
:if-exists if-output-exists)
(multiple-value-bind
(stderr error-stream)
(if (eq error :output)
(values stdout output-stream)
(get-descriptor-for error :direction :output
:if-exists if-error-exists))
(multiple-value-bind (pty-name pty-stream)
(open-pty pty)
;; Make sure we are not notified about the child death before
;; we have installed the process struct in *active-processes*
(system:without-interrupts
(multiple-value-bind
(child-pid errno)
(mach:unix-fork)
(cond ((zerop child-pid)
;; We are the child. Note: setup-child NEVER returns
(setup-child pfile args env stdin stdout stderr
pty-name before-execve))
((null child-pid)
;; This should only happen if the bozo has too
;; many running procs.
(error "Could not fork child process: ~A"
(mach:get-unix-error-msg errno)))
(t
;; We are the parent.
(setf proc (make-process :pid child-pid
:%status :running
:pty pty-stream
:input input-stream
:output output-stream
:error error-stream
:status-hook status-hook))
(push proc *active-processes*))))))))))
(dolist (fd *close-in-parent*)
(mach:unix-close fd))
(unless proc
(dolist (fd *close-on-error*)
(mach:unix-close fd))
(dolist (handler *handlers-installed*)
(system:remove-fd-handler handler))))
(when (and wait proc)
(process-wait proc))
proc))
;;; COPY-DESCRIPTOR-TO-STREAM -- internal
;;;
;;; Installs a handler for any input that shows up on the file descriptor.
;;; The handler reads the data and writes it to the stream.
;;;
(defun copy-descriptor-to-stream (descriptor stream)
(let ((string (make-string 256))
handler)
(setf handler
(system:add-fd-handler descriptor :input
#'(lambda (fd)
(declare (ignore fd))
(loop
(multiple-value-bind
(result readable/errno)
(mach:unix-select (1+ descriptor) (ash 1 descriptor)
0 0 0)
(cond ((null result)
(error "Could not select on sub-process: ~A"
(mach:get-unix-error-msg readable/errno)))
((zerop result)
(return))))
(multiple-value-bind
(count errno)
(mach:unix-read descriptor
string
(length string))
(cond ((or (and (null count)
(eql errno mach:eio))
(eql count 0))
(system:remove-fd-handler handler)
(mach:unix-close descriptor)
(return))
((null count)
(system:remove-fd-handler handler)
(error "Could not read input from sub-process: ~A"
(mach:get-unix-error-msg errno)))
(t
(write-string string stream
:end count))))))))))
;;; GET-DESCRIPTOR-FOR -- internal
;;;
;;; Find a file descriptor to use for object given the direction. Returns
;;; the descriptor. If object is :STREAM, returns the created stream as the
;;; second value.
;;;
(defun get-descriptor-for (object &rest keys &key direction &allow-other-keys)
(cond ((eq object t)
;; No new descriptor is needed.
(values nil nil))
((eq object nil)
;; Use /dev/null.
(multiple-value-bind
(fd errno)
(mach:unix-open "/dev/null"
(case direction
(:input mach:o_rdonly)
(:output mach:o_wronly)
(t mach:o_rdwr))
#o666)
(unless fd
(error "Could not open \"/dev/null\": ~A"
(mach:get-unix-error-msg errno)))
(push fd *close-in-parent*)
(values fd nil)))
((eq object :stream)
(multiple-value-bind
(read-fd write-fd)
(mach:unix-pipe)
(unless read-fd
(error "Could not create pipe: ~A"
(mach:get-unix-error-msg write-fd)))
(case direction
(:input
(push read-fd *close-in-parent*)
(push write-fd *close-on-error*)
(let ((stream (system:make-fd-stream write-fd :output t)))
(values read-fd stream)))
(:output
(push read-fd *close-on-error*)
(push write-fd *close-in-parent*)
(let ((stream (system:make-fd-stream read-fd :input t)))
(values write-fd stream)))
(t
(mach:unix-close read-fd)
(mach:unix-close write-fd)
(error "Direction must be either :INPUT or :OUTPUT, not ~S"
direction)))))
((stringp object)
(with-open-stream (file (apply #'open object keys))
(multiple-value-bind (won fd)
(mach:unix-dup (system:fd-stream-fd file))
(cond (won
(push fd *close-in-parent*)
(values fd nil))
(t
(error "Could not duplicate file descriptor: ~A"
(mach:get-unix-error-msg fd)))))))
((system:fd-stream-p object)
(values (system:fd-stream-fd object) nil))
((streamp object)
(ecase direction
(:input
(dotimes (count
256
(error "Could not open a temporary file in /tmp"))
(let* ((name (format nil "/tmp/.run-program-~D" count))
(fd (mach:unix-open name
(logior mach:o_rdwr
mach:o_creat
mach:o_excl)
#o666)))
(mach:unix-unlink name)
(when fd
(let ((newline (string #\Newline)))
(loop
(multiple-value-bind
(line no-cr)
(read-line object nil nil)
(unless line
(return))
(mach:unix-write fd line 0 (length line))
(if no-cr
(return)
(mach:unix-write fd newline 0 1)))))
(mach:unix-lseek fd 0 mach:l_set)
(push fd *close-in-parent*)
(return (values fd nil))))))
(:output
(multiple-value-bind (read-fd write-fd)
(mach:unix-pipe)
(unless read-fd
(error "Cound not create pipe: ~A"
(mach:get-unix-error-msg write-fd)))
(copy-descriptor-to-stream read-fd object)
(push read-fd *close-on-error*)
(push write-fd *close-in-parent*)
(values write-fd nil)))))
(t
(error "Invalid option to run-program: ~S" object))))
;;; -*- Log: code.log; Package: LISP -*-
;;; **********************************************************************
;;; This code was written as part of the Spice Lisp project at
;;; Carnegie-Mellon University, and has been placed in the public domain.
;;; If you want to use this code or any part of Spice Lisp, please contact
;;; Scott Fahlman (FAHLMAN@CMUC).
;;; **********************************************************************
;;;
;;; SYSTEM:SERVE-EVENT, now in it's own file.
;;;
;;; Re-written by William Lott, July 1989 - January 1990.
;;;
;;; **********************************************************************
(in-package "SYSTEM")
(export '(with-fd-handler add-fd-handler remove-fd-handler invalidate-descriptor
serve-event serve-all-events wait-until-fd-usable))
(in-package "LISP")
;;;; MACH Message receiving noise.
(defvar *in-server* NIL
"*In-server* is set to T when the SIGMSG interrupt has been enabled
in Server.")
(defvar server-unique-object (cons 1 2)
"Object thrown by the message interrupt handler.")
(defconstant server-message-size 4096)
(defalien server-message server-message (bytes server-message-size) 0)
(define-alien-stack server-message server-message (bytes server-message-size))
(defrecord server-message
(msg mach:msg #.(record-size 'mach:msg)))
;;; Grab-message-loop calls the appropiate handler for an IPC message.
(defun grab-message-loop ()
(let ((done-any nil))
(loop
(if (eql (server-grab-message)
mach:rcv-timed-out)
(return done-any)
(setf done-any t)))))
(defun server-grab-message ()
(with-stack-alien (sm server-message)
(alien-bind ((msg (server-message-msg (alien-value sm))))
(setf (alien-access (mach:msg-msgsize (alien-value msg)))
server-message-size)
(setf (alien-access (mach:msg-localport (alien-value msg)))
mach::port-enabled)
(let ((gr (mach:msg-receive (alien-value sm) mach::rcv-timeout 0)))
(when (eql gr mach:rcv-timed-out)
(return-from server-grab-message gr))
(unless (eql gr mach:rcv-success)
(gr-error 'mach:msg-receive gr))
(let* ((server-message (alien-value sm))
(port (alien-access (mach:msg-localport (alien-value msg))))
(id (alien-access (mach:msg-id (alien-value msg))))
(x (gethash port *port-table*))
(set (cdr x)))
(unless x
(error "~D is not known to server (operation: ~D)." port id))
(let ((gr (funcall (gethash id (object-set-table set)
(object-set-default-handler set))
(car x))))
(unless (eql gr mach:kern-success)
(gr-error 'server gr)))))))
mach:kern-success)
;;;; File descriptor IO noise.
(defstruct (handler
(:print-function %print-handler)
(:constructor make-handler (direction descriptor function)))
direction ; Either :input or :output
descriptor ; File descriptor this handler is tied to.
active ; T iff this handler is running.
function ; Function to call.
bogus ; T if this descriptor is bogus.
)
(defun %print-handler (handler stream depth)
(declare (ignore depth))
(format stream "#<Handler for ~A on ~:[~;BOGUS ~]descriptor ~D: ~S>"
(handler-direction handler)
(handler-bogus handler)
(handler-descriptor handler)
(handler-function handler)))
(defvar *descriptor-handlers* nil
"List of all the currently active handlers for file descriptors")
;;; ADD-FD-HANDLER -- public
;;;
;;; Add a new handler to *descriptor-handlers*.
;;;
(defun add-fd-handler (fd direction function)
"Arange to call FUNCTION whenever FD is usable. DIRECTION should be
either :INPUT or :OUTPUT. The value returned should be passed to
SYSTEM:REMOVE-FD-HANDLER when it is no longer needed."
(assert (member direction '(:input :output))
(direction)
"Invalid direction ~S, must be either :INPUT or :OUTPUT" direction)
(let ((handler (make-handler direction fd function)))
(push handler *descriptor-handlers*)
handler))
;;; REMOVE-FD-HANDLER -- public
;;;
;;; Remove an old handler from *descriptor-handlers*.
;;;
(defun remove-fd-handler (handler)
"Removes HANDLER from the list of active handlers."
(setf *descriptor-handlers*
(delete handler *descriptor-handlers*
:test #'eq)))
;;; INVALIDATE-DESCRIPTOR -- public
;;;
;;; Search *descriptor-handlers* for any reference to fd, and nuke 'em.
;;;
(defun invalidate-descriptor (fd)
"Remove any handers refering to fd. This should only be used when attempting
to recover from a detected inconsistancy."
(setf *descriptor-handlers*
(delete fd *descriptor-handlers*
:key #'handler-descriptor)))
;;; WITH-FD-HANDLER -- Public.
;;;
;;; Add the handler to *descriptor-handlers* for the duration of BODY.
;;;
(defmacro with-fd-handler ((fd direction function) &rest body)
"Establish a handler with SYSTEM:ADD-FD-HANDLER for the duration of BODY.
DIRECTION should be either :INPUT or :OUTPUT, FD is the file descriptor to
use, and FUNCTION is the function to call whenever FD is usable."
(let ((handler (gensym)))
`(let (,handler)
(unwind-protect
(progn
(setf ,handler (add-fd-handler ,fd ,direction ,function))
,@body)
(when ,handler
(remove-fd-handler ,handler))))))
;;; WAIT-UNTIL-FD-USABLE -- Public.
;;;
;;; Wait until FD is usable for DIRECTION. The timeout given to serve-event is
;;; recalculated each time through the loop so that WAIT-UNTIL-FD-USABLE will
;;; timeout at the correct time irrespective of how many events are handled in
;;; the meantime.
;;;
(defun wait-until-fd-usable (fd direction &optional timeout)
"Wait until FD is usable for DIRECTION. DIRECTION should be either :INPUT or
:OUTPUT. TIMEOUT, if supplied, is the number of seconds to wait before giving
up."
(let (usable
(stop-at (if timeout
(multiple-value-bind (okay sec usec)
(mach:unix-gettimeofday)
(declare (ignore okay))
(+ (* 1000000 timeout sec) usec)))))
(with-fd-handler (fd direction #'(lambda (fd)
(declare (ignore fd))
(setf usable t)))
(loop
(serve-event timeout)
(when usable
(return t))
(when timeout
(multiple-value-bind (okay sec usec)
(mach:unix-gettimeofday)
(declare (ignore okay))
(let ((now (+ (* sec 1000000) usec)))
(if (> now stop-at)
(return nil)
(setq timeout
(/ (- stop-at now)
1000000))))))))))
;;; CALC-MASKS -- Internal.
;;;
;;; Return the correct masks to use for UNIX-SELECT. The four return values
;;; are: fd count, read mask, write mask, and exception mask. The exception
;;; mask is currently unused.
;;;
(defun calc-masks ()
(let ((count 0)
(read-mask 0)
(write-mask 0)
(except-mask 0))
(dolist (handler *descriptor-handlers*)
(unless (or (handler-active handler)
(handler-bogus handler))
(let ((fd (handler-descriptor handler)))
(case (handler-direction handler)
(:input
(setf read-mask (logior read-mask (ash 1 fd))))
(:output
(setf write-mask (logior write-mask (ash 1 fd)))))
(if (> fd count)
(setf count fd)))))
(values (1+ count)
read-mask
write-mask
except-mask)))
;;; HANDLER-DESCRIPTORS-ERROR -- Internal.
;;;
;;; First, get a list and mark bad file descriptors. Then signal an error
;;; offering a few restarts.
;;;
(defun handler-descriptors-error ()
(let ((bogus-handlers nil))
(dolist (handler *descriptor-handlers*)
(unless (or (handler-bogus handler)
(mach:unix-fstat (handler-descriptor handler)))
(setf (handler-bogus handler) t)
(push handler bogus-handlers)))
(restart-case (error "~S ~[have~;has a~:;have~] bad file descriptor~:P."
bogus-handlers (length bogus-handlers))
(remove-them () :report "Remove bogus handlers."
(setf *descriptor-handlers*
(delete-if #'handler-bogus *descriptor-handlers*)))
(retry-them () :report "Retry bogus handlers."
(dolist (handler bogus-handlers)
(setf (handler-bogus handler) nil)))
(continue () :report "Go on, leaving handlers marked as bogus."))))
;;;; Serve-all-events, serve-event, and friends.
;;; SERVE-ALL-EVENTS -- public
;;;
;;; Wait for up to timeout seconds for an event to happen. Make sure all
;;; pending events are processed before returning.
;;;
(defun serve-all-events (&optional timeout)
"SERVE-ALL-EVENTS calls SERVE-EVENT with the specified timeout. If
SERVE-EVENT does something (returns T) it loops over SERVE-EVENT with timeout
0 until all events have been served. SERVE-ALL-EVENTS returns T if
SERVE-EVENT did something and NIL if not."
(do ((res nil)
(sval (serve-event timeout) (serve-event 0)))
((null sval) res)
(setq res t)))
;;; SERVE-EVENT -- public
;;;
;;; Serve a single event.
;;;
(defun serve-event (&optional timeout)
"Receive on all ports and Xevents and dispatch to the appropriate handler
function. If timeout is specified, server will wait the specified time (in
seconds) and then return, otherwise it will wait until something happens.
Server returns T if something happened and NIL otherwise."
;; First, check any X displays for any pending events.
(dolist (d/h ext::*display-event-handlers*)
(let ((d (car d/h)))
(when (xlib::event-listen d)
(handler-bind ((error #'(lambda (condx)
(declare (ignore condx))
(flush-display-events d))))
(funcall (cdr d/h) d))
(return-from serve-event t))))
;; Next, wait for something to happen.
(multiple-value-bind
(value readable writeable)
(wait-for-event timeout)
;; Now see what it was (if anything)
(cond ((eq value server-unique-object)
;; The interrupt handler fired.
(grab-message-loop)
t)
((numberp value)
(unless (zerop value)
;; Check the descriptors.
(let ((result nil))
(dolist (handler *descriptor-handlers*)
(when (not (zerop (logand (ash 1 (handler-descriptor handler))
(case (handler-direction handler)
(:input readable)
(:output writeable)))))
(unwind-protect
(progn
;; Doesn't work -- ACK
;(setf (handler-active handler) t)
(funcall (handler-function handler)
(handler-descriptor handler)))
(setf (handler-active handler) nil))
(macrolet ((frob (var)
`(setf ,var
(logand (lognot (ash 1
(handler-descriptor
handler)))
,var))))
(case (handler-direction handler)
(:input (frob readable))
(:output (frob writeable))))
(setf result t)))
result)))
((eql readable mach:eintr)
;; We did an interrupt.
t)
(t
;; One of the file descriptors is bad.
(handler-descriptors-error)
nil))))
;;; WAIT-FOR-EVENT -- internal
;;;
;;; Wait for something to happen.
;;;
(defun wait-for-event (&optional timeout)
"Wait for an something to show up on one of the file descriptors or a message
interupt to fire. Timeout is in seconds."
(let (old-mask)
(multiple-value-bind (timeout-sec timeout-usec)
(if timeout
(truncate (round (* timeout 1000000)) 1000000)
(values nil 0))
(multiple-value-bind (count read-mask write-mask except-mask)
(calc-masks)
(catch 'server-catch
(unwind-protect
(progn
;; Block message interrupts.
(multiple-value-bind
(noise mask)
(mach:unix-sigsetmask (mach:sigmask :sigmsg))
(declare (ignore noise))
(setf old-mask mask))
;; Check for any pending messages, because we are only signaled
;; for newly arived messages. This must be done after the
;; unix-sigsetmask.
(when (grab-message-loop)
(return-from wait-for-event t))
;; Indicate that we are in the server.
(let ((*in-server* t))
;; Establish the interrupt handlers.
(enable-interrupt mach:sigmsg #'ih-sigmsg)
;; Enable all interrupts.
(mach:unix-sigsetmask 0)
;; Do the select.
(mach:unix-select count read-mask write-mask except-mask
timeout-sec timeout-usec)))
;; Restore interrupt handler state.
(mach:unix-sigsetmask (mach:sigmask :sigmsg))
(default-interrupt mach:sigmsg)
(mach:unix-sigsetmask old-mask)))))))
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