0.9.16.6: better circularity detection in fasl dumper
[sbcl.git] / src / code / fd-stream.lisp
index 1afdecf..ef0c2c4 100644 (file)
                      (intern (format nil name-fmt (string (car buffering))))))
                 `(progn
                    (defun ,function (stream byte)
+                     (declare (ignorable byte))
                      (output-wrapper/variable-width (stream ,size ,buffering ,restart)
                        ,@body))
                    (setf *output-routines*
 ;;; per element.
 (defvar *input-routines* ())
 
+;;; Return whether a primitive partial read operation on STREAM's FD
+;;; would (probably) block.  Signal a `simple-stream-error' if the
+;;; system call implementing this operation fails.
+;;;
+;;; It is "may" instead of "would" because "would" is not quite
+;;; correct on win32.  However, none of the places that use it require
+;;; further assurance than "may" versus "will definitely not".
+(defun sysread-may-block-p (stream)
+  #+win32
+  ;; This answers T at EOF on win32, I think.
+  (not (sb!win32:fd-listen (fd-stream-fd stream)))
+  #-win32
+  (sb!unix:with-restarted-syscall (count errno)
+    (sb!alien:with-alien ((read-fds (sb!alien:struct sb!unix:fd-set)))
+      (sb!unix:fd-zero read-fds)
+      (sb!unix:fd-set (fd-stream-fd stream) read-fds)
+      (sb!unix:unix-fast-select (1+ (fd-stream-fd stream))
+                                (sb!alien:addr read-fds)
+                                nil nil 0 0))
+    (case count
+      ((1) nil)
+      ((0) t)
+      (otherwise
+       (simple-stream-perror "couldn't check whether ~S is readable"
+                             stream
+                             errno)))))
+
 ;;; Fill the input buffer, and return the number of bytes read. Throw
 ;;; to EOF-INPUT-CATCHER if the eof was reached. Drop into
 ;;; SYSTEM:SERVER if necessary.
              (setf (fd-stream-ibuf-head stream) 0)
              (setf (fd-stream-ibuf-tail stream) tail))))
     (setf (fd-stream-listen stream) nil)
-    #!+win32
-    (unless (sb!win32:fd-listen fd)
+    ;;This isn't quite the same on win32.  Then again, neither was
+    ;;(not (sb!win32:fd-listen fd)), as was originally here.  See
+    ;;comment in `sysread-may-block-p'.
+    (when (sysread-may-block-p stream)
       (unless (sb!sys:wait-until-fd-usable
                fd :input (fd-stream-timeout stream))
         (error 'io-timeout :stream stream :direction :read)))
-    #!-win32
-    (sb!unix:with-restarted-syscall (count errno)
-      ;; FIXME: Judging from compiler warnings, this WITH-ALIEN form expands
-      ;; into something which uses the not-yet-defined type
-      ;;   (SB!ALIEN-INTERNALS:ALIEN (* (SB!ALIEN:STRUCT SB!UNIX:FD-SET))).
-      ;; This is probably inefficient and unsafe and generally bad, so
-      ;; try to find some way to make that type known before
-      ;; this is compiled.
-      (sb!alien:with-alien ((read-fds (sb!alien:struct sb!unix:fd-set)))
-        (sb!unix:fd-zero read-fds)
-        (sb!unix:fd-set fd read-fds)
-        (sb!unix:unix-fast-select (1+ fd)
-                                  (sb!alien:addr read-fds)
-                                  nil nil 0 0))
-      (case count
-        (1)
-        (0
-         (unless (sb!sys:wait-until-fd-usable
-                  fd :input (fd-stream-timeout stream))
-           (error 'io-timeout :stream stream :direction :read)))
-        (t
-         (simple-stream-perror "couldn't check whether ~S is readable"
-                               stream
-                               errno))))
     (multiple-value-bind (count errno)
         (sb!unix:unix-read fd
                            (sb!sys:int-sap (+ (sb!sys:sap-int ibuf-sap) tail))
                                                       ,stream-var)
                                                      (fd-stream-ibuf-head
                                                       ,stream-var))))
+                               (declare (ignorable byte))
                                (setq size ,bytes)
                                (input-at-least ,stream-var size)
                                (setq ,element-var (locally ,@read-forms))
     (when sizer
       (loop for char across string summing (funcall sizer char)))))
 
+(defun find-external-format (external-format)
+  (when external-format
+    (find external-format *external-formats* :test #'member :key #'car)))
+
+(defun variable-width-external-format-p (ef-entry)
+  (when (eighth ef-entry) t))
+
+(defun bytes-for-char-fun (ef-entry)
+  (if ef-entry (symbol-function (ninth ef-entry)) (constantly 1)))
+
 ;;; FIXME: OAOOM here vrt. *EXTERNAL-FORMAT-FUNCTIONS* in fd-stream.lisp
 (defmacro define-external-format (external-format size output-restart
                                   out-expr in-expr)
          (size-function (symbolicate "BYTES-FOR-CHAR/" name)))
     `(progn
       (defun ,size-function (byte)
+        (declare (ignorable byte))
         ,out-size-expr)
       (defun ,out-function (stream string flush-p start end)
         (let ((start (or start 0))
               (setf decode-break-reason
                     (block decode-break-reason
                       (let ((byte (sap-ref-8 sap head)))
+                        (declare (ignorable byte))
                         (setq size ,in-size-expr)
                         (when (> size (- tail head))
                           (return))
                                                            ,in-size-expr
                                                            sap head)
         (let ((byte (sap-ref-8 sap head)))
+          (declare (ignorable byte))
           ,in-expr))
       (defun ,resync-function (stream)
-        (loop (input-at-least stream 1)
+        (loop (input-at-least stream 2)
               (incf (fd-stream-ibuf-head stream))
               (unless (block decode-break-reason
                         (let* ((sap (fd-stream-ibuf-sap stream))
                                (head (fd-stream-ibuf-head stream))
                                (byte (sap-ref-8 sap head))
                                (size ,in-size-expr))
-                          ,in-expr)
+                          (declare (ignorable byte))
+                          (input-at-least stream size)
+                          (let ((sap (fd-stream-ibuf-sap stream))
+                                (head (fd-stream-ibuf-head stream)))
+                            ,in-expr))
                         nil)
                 (return))))
       (setf *external-formats*
   (declare (ignore arg2))
   (case operation
     (:listen
-     (or (not (eql (fd-stream-ibuf-head fd-stream)
-                   (fd-stream-ibuf-tail fd-stream)))
-         (fd-stream-listen fd-stream)
-         #!+win32
-         (setf (fd-stream-listen fd-stream)
-               (sb!win32:fd-listen (fd-stream-fd fd-stream)))
-         #!-win32
-         (setf (fd-stream-listen fd-stream)
-               (eql (sb!unix:with-restarted-syscall ()
-                      (sb!alien:with-alien ((read-fds (sb!alien:struct
-                                                       sb!unix:fd-set)))
-                        (sb!unix:fd-zero read-fds)
-                        (sb!unix:fd-set (fd-stream-fd fd-stream) read-fds)
-                        (sb!unix:unix-fast-select (1+ (fd-stream-fd fd-stream))
-                                                  (sb!alien:addr read-fds)
-                                                  nil nil 0 0)))
-                    1))))
+     (labels ((do-listen ()
+                (or (not (eql (fd-stream-ibuf-head fd-stream)
+                              (fd-stream-ibuf-tail fd-stream)))
+                    (fd-stream-listen fd-stream)
+                    #!+win32
+                    (sb!win32:fd-listen (fd-stream-fd fd-stream))
+                    #!-win32
+                    ;; If the read can block, LISTEN will certainly return NIL.
+                    (if (sysread-may-block-p fd-stream)
+                        nil
+                        ;; Otherwise select(2) and CL:LISTEN have slightly
+                        ;; different semantics.  The former returns that an FD
+                        ;; is readable when a read operation wouldn't block.
+                        ;; That includes EOF.  However, LISTEN must return NIL
+                        ;; at EOF.
+                        (progn (catch 'eof-input-catcher
+                                 ;; r-b/f too calls select, but it shouldn't
+                                 ;; block as long as read can return once w/o
+                                 ;; blocking
+                                 (refill-buffer/fd fd-stream))
+                               ;; At this point either IBUF-HEAD != IBUF-TAIL
+                               ;; and FD-STREAM-LISTEN is NIL, in which case
+                               ;; we should return T, or IBUF-HEAD ==
+                               ;; IBUF-TAIL and FD-STREAM-LISTEN is :EOF, in
+                               ;; which case we should return :EOF for this
+                               ;; call and all future LISTEN call on this stream.
+                               ;; Call ourselves again to determine which case
+                               ;; applies.
+                               (do-listen))))))
+       (do-listen)))
     (:unread
      (setf (fd-stream-unread fd-stream) arg1)
      (setf (fd-stream-listen fd-stream) t))
     (:close
-     (cond (arg1 ; We got us an abort on our hands.
+     (cond (arg1                    ; We got us an abort on our hands.
             (when (fd-stream-handler fd-stream)
               (sb!sys:remove-fd-handler (fd-stream-handler fd-stream))
               (setf (fd-stream-handler fd-stream) nil))
        (setf (fd-stream-listen fd-stream) nil))
      #!-win32
      (catch 'eof-input-catcher
-       (loop
-        (let ((count (sb!unix:with-restarted-syscall ()
-                       (sb!alien:with-alien ((read-fds (sb!alien:struct
-                                                        sb!unix:fd-set)))
-                         (sb!unix:fd-zero read-fds)
-                         (sb!unix:fd-set (fd-stream-fd fd-stream) read-fds)
-                         (sb!unix:unix-fast-select (1+ (fd-stream-fd fd-stream))
-                                                   (sb!alien:addr read-fds)
-                                                   nil nil 0 0)))))
-          (cond ((eql count 1)
-                 (refill-buffer/fd fd-stream)
-                 (setf (fd-stream-ibuf-head fd-stream) 0)
-                 (setf (fd-stream-ibuf-tail fd-stream) 0))
-                (t
-                 (return t)))))))
+       (loop until (sysread-may-block-p fd-stream)
+             do
+             (refill-buffer/fd fd-stream)
+             (setf (fd-stream-ibuf-head fd-stream) 0)
+             (setf (fd-stream-ibuf-tail fd-stream) 0))
+       t))
     (:force-output
      (flush-output-buffer fd-stream))
     (:finish-output
               :format-control "~S is not a stream associated with a file."
               :format-arguments (list fd-stream)))
      (multiple-value-bind (okay dev ino mode nlink uid gid rdev size
-                           atime mtime ctime blksize blocks)
+                                atime mtime ctime blksize blocks)
          (sb!unix:unix-fstat (fd-stream-fd fd-stream))
        (declare (ignore ino nlink uid gid rdev
                         atime mtime ctime blksize blocks))
   (setf *available-buffers* nil)
   (with-output-to-string (*error-output*)
     (setf *stdin*
-          (make-fd-stream 0 :name "standard input" :input t :buffering :line))
+          (make-fd-stream 0 :name "standard input" :input t :buffering :line
+                            #!+win32 :external-format #!+win32 (sb!win32::console-input-codepage)))
     (setf *stdout*
-          (make-fd-stream 1 :name "standard output" :output t :buffering :line))
+          (make-fd-stream 1 :name "standard output" :output t :buffering :line
+                            #!+win32 :external-format #!+win32 (sb!win32::console-output-codepage)))
     (setf *stderr*
-          (make-fd-stream 2 :name "standard error" :output t :buffering :line))
+          (make-fd-stream 2 :name "standard error" :output t :buffering :line
+                            #!+win32 :external-format #!+win32 (sb!win32::console-output-codepage)))
     (let* ((ttyname #.(coerce "/dev/tty" 'simple-base-string))
            (tty (sb!unix:unix-open ttyname sb!unix:o_rdwr #o666)))
       (if tty