[slime-devel] [patch] fd-handler communication style support in swank-ecl

[Ram Krishnan]

Hi,

Here's a minor patch to add support for the `fd-handler' communication
style in swank-ecl.lisp. I've only tested this with ECL 9.8.4 and SLIME
CVS on OSX. I can't think of any reason why this shouldn't "just work"
on any reasonable *nix on which ECL runs, and includes the SOCKETS and
SERVE-EVENT modules.

There is a known issue with this patch, with disconnecting from and
reconnecting to the swank server. The reconnection will hang, until
`(serve-event:serve-event)' is evaluated in the *inferior-lisp* buffer.

Regards,

-ram

Index: swank-ecl.lisp
===================================================================
RCS file: /project/slime/cvsroot/slime/swank-ecl.lisp,v
retrieving revision 1.45
diff -u -8 -p -r1.45 swank-ecl.lisp
--- swank-ecl.lisp	27 Jul 2009 04:08:41 -0000	1.45
+++ swank-ecl.lisp	31 Aug 2009 05:30:45 -0000
@@ -44,16 +44,17 @@
     (sb-bsd-sockets:socket-bind socket (resolve-hostname host) port)
     (sb-bsd-sockets:socket-listen socket 5)
     socket))
 
 (defimplementation local-port (socket)
   (nth-value 1 (sb-bsd-sockets:socket-name socket)))
 
 (defimplementation close-socket (socket)
+  (remove-fd-handlers socket)
   (sb-bsd-sockets:socket-close socket))
 
 (defimplementation accept-connection (socket
                                       &key external-format
                                       buffering timeout)
   (declare (ignore buffering timeout external-format))
   (make-socket-io-stream (accept socket)))
 
@@ -65,17 +66,17 @@
 
 (defun accept (socket)
   "Like socket-accept, but retry on EAGAIN."
   (loop (handler-case
             (return (sb-bsd-sockets:socket-accept socket))
           (sb-bsd-sockets:interrupted-error ()))))
 
 (defimplementation preferred-communication-style ()
-  (values nil))
+  (values :fd-handler))
 
 (defvar *external-format-to-coding-system*
   '((:iso-8859-1
      "latin-1" "latin-1-unix" "iso-latin-1-unix" 
      "iso-8859-1" "iso-8859-1-unix")
     (:utf-8 "utf-8" "utf-8-unix")))
 
 (defimplementation find-external-format (coding-system)
@@ -111,16 +112,58 @@
 #+nil
 (defimplementation default-directory ()
   (namestring (ext:getcwd)))
 
 (defimplementation quit-lisp ()
   (ext:quit))
 
 
+;;;; Serve Event Handlers
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (require 'serve-event))
+
+(defun socket-fd (socket)
+  (etypecase socket
+    (fixnum socket)
+    (sb-bsd-sockets:socket (sb-bsd-sockets:socket-file-descriptor socket))
+    (file-stream (si:file-stream-fd socket))))
+
+(defvar *descriptor-handlers* (make-hash-table :test 'eq))
+
+(defimplementation add-fd-handler (socket fun)
+  (let* ((fd (socket-fd socket))
+         (handler (gethash fd *descriptor-handlers*)))
+    (when handler
+      (serve-event:remove-fd-handler handler))
+    (prog1
+        (setf (gethash fd *descriptor-handlers*)
+              (serve-event:add-fd-handler fd
+                                          :input
+                                          #'(lambda (x)
+                                              (declare (ignorable x))
+                                              (funcall fun))))
+      (serve-event:serve-event))))
+
+(defimplementation remove-fd-handlers (socket)
+  (let ((handler (gethash (socket-fd socket) *descriptor-handlers*)))
+    (when handler
+      (serve-event:remove-fd-handler handler))))
+
+(defimplementation wait-for-input (streams &optional timeout)
+  (assert (member timeout '(nil t)))
+  (loop
+     (let ((ready (remove-if-not #'listen streams)))
+       (when ready (return ready)))
+     ;; (when timeout (return nil))
+     (when (check-slime-interrupts) (return :interrupt))
+     (serve-event:serve-event)))
+
+
 ;;;; Compilation
 
 (defvar *buffer-name* nil)
 (defvar *buffer-start-position*)
 (defvar *buffer-string*)
 (defvar *compile-filename*)
 
 (defun signal-compiler-condition (&rest args)
@@ -490,16 +533,19 @@
                                  #-#.(swank-backend::with-symbol '+ECL-VERSION-NUMBER+ 'EXT)
                                  (skip-toplevel-forms pos s)
                                  (skip-comments-and-whitespace s)
                                  (read-snippet s))))))))
    `(:error (format nil "Source definition of ~S not found" obj))))
 
 ;;;; Profiling
 
+#+profile
+(progn
+
 (eval-when (:compile-toplevel :load-toplevel :execute)
   (require 'profile))
 
 (defimplementation profile (fname)
   (when fname (eval `(profile:profile ,fname))))
 
 (defimplementation unprofile (fname)
   (when fname (eval `(profile:unprofile ,fname))))
@@ -516,17 +562,17 @@
   "Reset profiling counters.")
 
 (defimplementation profiled-functions ()
   (profile:profile))
 
 (defimplementation profile-package (package callers methods)
   (declare (ignore callers methods))
   (eval `(profile:profile ,(package-name (find-package package)))))
-
+)                                       ; progn
 
 ;;;; Threads
 
 #+threads
 (progn
   (defvar *thread-id-counter* 0)
 
   (defvar *thread-id-counter-lock*