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[kmrcl.git] / listener.lisp

diff --git a/listener.lisp b/listener.lisp
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+;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10; Package: modlisp -*-
+;;;; *************************************************************************
+;;;; FILE IDENTIFICATION
+;;;;
+;;;; Name:          listener.lisp
+;;;; Purpose:       Listener and worker processes
+;;;; Programmer:    Kevin M. Rosenberg
+;;;; Date Started:  Dec 2002
+;;;;
+;;;; $Id: listener.lisp,v 1.1 2003/07/08 16:12:40 kevin Exp $
+;;;; *************************************************************************
+
+(in-package #:kmrcl)
+
+;;; Variables and data structures for Listener
+
+(defvar *listener-count* 0
+  "used to name listeners")
+
+(defvar *worker-count* 0
+  "used to name workers")
+
+(defvar *active-listeners* nil
+    "List of active listeners")
+
+(defclass listener ()
+  ((port :initarg :port :accessor port) 
+   (function :initarg :function :accessor listener-function
+            :initform nil)
+   (function-args :initarg :function-args :accessor function-args
+                 :initform nil)
+   (process :initarg :process :accessor process)
+   (socket :initarg :socket :accessor socket)
+   (workers :initform nil :accessor workers
+           :documentation "list of worker threads")
+   (name :initform "" :accessor name :initarg :name)
+   (base-name :initform "listener" :accessor base-name :initarg :base-name)
+   (wait :initform nil :accessor wait :initarg :wait)
+   (catch-errors :initform nil :accessor catch-errors :initarg :catch-errors)
+   (format :initform :text :accessor listener-format :initarg :format)))
+
+(defclass worker ()
+  ((listener :initarg :listener :accessor listener :initform nil)
+   (connection :initarg :connection :accessor connection :initform nil)
+   (name :initarg :name :accessor name :initform nil)
+   (thread-fun :initarg :thread-fun :accessor thread-fun :initform nil)
+   (process :initarg :process :accessor process :initform nil)))
+
+
+;; High-level API
+
+(defun init/listener (listener state)
+  (check-type listener listener)
+  (case state
+    (:start
+     (when (member listener *active-listeners*)
+       (warn "~&listener already started")
+       (return-from init/listener listener))
+     (handler-case
+        (progn
+          (setf (name listener) (next-server-name (base-name listener)))
+          (make-socket-server listener))
+       (error (e)
+        (format t "~&Error while trying to start listener~&  ~A" e)
+        (decf *listener-count*)
+        nil)
+       (:no-error (res)
+        (declare (ignore res))
+        (push listener *active-listeners*)
+        listener)))
+    (:stop
+     (unless (member listener *active-listeners*)
+       (warn "~&listener is not in active list")
+       (return-from init/listener listener))
+     (dolist (worker (workers listener))
+       (close-active-socket (connection worker))
+       (destroy-process (process worker)))
+     (setf (workers listener) nil)
+     (with-slots (process socket) listener
+       (errorset (close-passive-socket socket) t)
+       (errorset (destroy-process process) t))
+     (setq *active-listeners* (remove listener *active-listeners*)))
+    (:restart
+     (init/listener listener :stop)
+     (init/listener listener :start))))
+
+(defun stop-all/listener ()
+  (dolist (listener *active-listeners*)
+    (ignore-errors
+       (init/listener listener :stop))))
+
+;; Low-level functions
+
+(defun next-server-name (base-name)
+  (format nil "~A-socket-server-~D" base-name (incf *listener-count*))) 
+
+(defun next-worker-name (base-name)
+  (format nil "~A-worker-~D" base-name (incf *worker-count*)))
+
+(defun make-socket-server (listener)
+  (setf (socket listener) (create-inet-listener
+                          (port listener)
+                          :format (listener-format listener)))
+  (setf (process listener) (make-process
+                           (name listener)
+                           #'(lambda () (start-socket-server listener))))
+  listener)
+
+
+(defmethod initialize-instance :after
+    ((self worker) &key listener connection name &allow-other-keys)
+  (unless connection
+    (error "connection not provided to modlisp-worker"))
+  (setf (slot-value self 'listener) listener)
+  (setf (slot-value self 'name) name)
+  (setf (slot-value self 'connection) connection)
+  (setf (slot-value self 'thread-fun)
+       #'(lambda ()
+           (unwind-protect
+               (if (catch-errors listener)
+                   (handler-case
+                       (apply (listener-function listener)
+                              connection
+                              (function-args listener))
+                     (error (e)
+                       (cmsg "Error ~A [~A]" e name)))
+                 (apply (listener-function listener)
+                        connection
+                        (function-args listener)))
+         (progn
+           (errorset (close-active-socket connection) nil)
+           (cmsg-c :threads "~A ended" name)
+           (setf (workers listener)
+                 (remove self (workers listener))))))))
+
+(defun start-socket-server (listener)
+  (unwind-protect
+      (loop 
+       (let ((connection (accept-tcp-connection (socket listener))))
+        (if (wait listener)
+            (unwind-protect
+                 (apply (listener-function listener)
+                        connection
+                        (function-args listener))
+              (errorset (close connection) nil))
+            (let ((worker (make-instance 'worker :listener listener
+                                         :connection connection
+                                         :name (next-worker-name
+                                                (base-name listener)))))
+             (setf (process worker)
+               (make-process (name worker) (thread-fun worker)))
+             (push worker (workers listener))))))
+    (errorset (close-passive-socket (socket listener)) nil)))