kmx.io/cl-thot/thot-epoll.lisp

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• Hash : 7475d49c
  Author : Thomas de Grivel
  Date : 2017-08-01T22:31:13
  

  catch conditions in epoll reader cont

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• thot-epoll.lisp

• 
  (in-package :thot)
  
  ;;  epoll infos
  
  (defclass epoll-infos ()
    ((fd :initarg :fd
         :reader epoll-fd
         :type (unsigned-byte 31))
     (agents :initform (make-hash-table)
             :reader epoll-agents
             :type hash-table)))
  
  ;;  Generic epoll agent class
  
  (defclass agent ()
    ((fd :initarg :fd
         :reader agent-fd
         :type (unsigned-byte 31))))
  
  (defgeneric agent-epoll-events (agent))
  (defgeneric agent-error (epoll agent))
  (defgeneric agent-in (epoll agent))
  (defgeneric agent-out (epoll agent))
  
  (define-condition agent-error (error)
    ((agent :initarg :agent
            :reader agent-error-agent
            :type agent)))
  
  ;;  Adding an agent
  
  (defmacro get-agent (epoll fd)
    `(gethash ,fd (epoll-agents ,epoll)))
  
  (defun remove-agent (epoll fd)
    (declare (type epoll-infos epoll))
    (remhash fd (epoll-agents epoll)))
  
  (defun epoll-add (epoll agent)
    (declare (type epoll-infos epoll))
    (let ((fd (agent-fd agent)))
      (set-nonblocking fd)
      (setf (get-agent epoll fd) agent)
      (epoll:add (epoll-fd epoll) fd
                 (agent-epoll-events agent)
                 :data-fd fd)))
  
  (defun epoll-del (epoll agent)
    (declare (type epoll-infos epoll))
    (let ((fd (agent-fd agent)))
      (epoll:del (epoll-fd epoll) fd)
      (socket:shutdown fd t t)
      (unistd:close fd)
      (remove-agent epoll fd)))
  
  ;;  Worker agent
  
  (defclass worker (agent)
    ((addr :initarg :addr
           :reader worker-addr)
     (keep-alive :initform nil
                 :accessor worker-keep-alive
                 :type boolean)
     (reader-cont :initarg :reader-cont
                  :accessor worker-reader-cont
                  :type (or null function))
     (reply :initarg :reply
            :accessor worker-reply
            :type 'reply)
     (request :initarg :request
              :accessor worker-request
              :type 'request)))
  
  (defmethod agent-epoll-events ((worker worker))
    (logior epoll:+in+ epoll:+out+ epoll:+err+))
  
  (define-condition worker-error (agent-error)
    ())
  
  (defmethod agent-error ((epoll epoll-infos) (worker worker))
    (error 'worker-error :agent worker))
  
  (defmethod agent-in ((epoll epoll-infos) (worker worker))
    (let ((reader-cont (worker-reader-cont worker)))
      (when reader-cont
        (let ((result (handler-case (funcall reader-cont)
                        (t (condition) (format t "~A~%" condition) :eof))))
          (cond ((eq :eof result) (epoll-del epoll worker))
                ((eq nil result) (setf (worker-reader-cont worker) nil))
                ((eq :keep-alive result) (setf (worker-keep-alive worker) t
                                               (worker-reader-cont worker) nil)
                 :keep-alive)
                ((functionp result) (setf (worker-reader-cont worker) result))
                (t (error "worker input error ~S" worker)))))))
  
  (defmethod agent-out ((epoll epoll-infos) (worker worker))
    (let* ((request (worker-request worker))
           (reply (worker-reply worker))
           (babel-stream (reply-stream reply))
           (stream (stream-underlying-stream babel-stream)))
      (cond ((and (null (worker-reader-cont worker))
                  (= 0 (stream-output-length stream)))
             (cond ((worker-keep-alive worker)
                    ;; read request body
                    (setf (worker-reader-cont worker)
                          (request-reader (reset-request request)
                                          (reset-reply reply)
                                          #'request-cont))
                    (agent-in epoll worker))
                   (t
                    (epoll-del epoll worker))))
            (t
             (case (stream-flush-output-buffer stream)
               ((nil) nil)
               ((:eof) (epoll-del epoll worker))
               ((:non-blocking) :non-blocking)
               (otherwise (error 'stream-output-error :stream stream)))))))
  
  ;;  Acceptor agent
  
  (defclass acceptor (agent)
    ())
  
  (defmethod agent-epoll-events ((agent acceptor))
    (logior epoll:+in+ epoll:+err+))
  
  (define-condition acceptor-error (agent-error)
    ())
  
  (defmethod agent-error ((epoll epoll-infos) (acceptor acceptor))
    (error 'acceptor-error :agent acceptor))
  
  (defun make-worker (fd addr)
    (let* ((request-stream (babel-input-stream (fd-input-stream fd)))
           (reply-stream (babel-output-stream
                          (multi-buffered-output-stream
                           (fd-output-stream fd))))
           (request (make-instance 'request :stream request-stream))
           (reply (make-instance 'reply :stream reply-stream))
           (reader-cont (request-reader request reply #'request-cont)))
      (make-instance 'worker
                     :addr addr
                     :fd fd
                     :reader-cont reader-cont
                     :request request
                     :reply reply)))
  
  (defmethod agent-in ((epoll epoll-infos) (acceptor acceptor))
    (multiple-value-bind (fd addr) (socket:accept (agent-fd acceptor))
      (unless (eq :non-blocking fd)
        (epoll-add epoll (make-worker fd addr)))))
  
  (defclass control (agent)
    ())
  
  (defmethod agent-epoll-events ((agent control))
    epoll:+in+)
  
  (defmethod agent-in ((epoll epoll-infos) (agent control))
    (setq *stop* t))
  
  ;;  Thread event loop
  
  (defun acceptor-loop-epoll (listenfd &optional pipe)
    (declare (type (unsigned-byte 31) listenfd))
    (labels ((acceptor-loop-epoll-fun ()
               (epoll:with (epoll-fd)
                 (let ((epoll (make-instance 'epoll-infos :fd epoll-fd)))
                   (epoll-add epoll (make-instance 'acceptor :fd listenfd))
                   (when pipe
                     (epoll-add epoll (make-instance 'control :fd pipe)))
                   (loop
                      (when *stop*
                        (return))
                      (epoll:wait (events fd epoll-fd)
                        (let ((agent (get-agent epoll fd)))
                          (unless agent (error "bad epoll fd ~S" fd))
                          (cond ((not (= 0 (logand epoll:+err+ events)))
                                 (agent-error epoll agent))
                                ((not (= 0 (logand epoll:+in+ events)))
                                 (agent-in epoll agent))
                                ((not (= 0 (logand epoll:+out+ events)))
                                 (agent-out epoll agent))))))))))
      #'acceptor-loop-epoll-fun))
  
  (when (cffi:foreign-symbol-pointer "epoll_create")
    (cond ((eq *acceptor-loop* 'acceptor-loop-simple)
           (setq *acceptor-loop* 'acceptor-loop-epoll))
          ((eq *acceptor-loop* 'acceptor-loop-threaded)
           (setq *worker-thread-for-fd* 'acceptor-loop-epoll))))
  
  (trace socket:socket socket:bind socket:listen socket:accept
         unistd:close
         epoll:create
         epoll-add epoll-del
         acceptor-loop-epoll make-worker agent-in agent-out)
  

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