jvideo/src/POSIX/decunix/Jv.m3


Copyright (C) 1994, Digital Equipment Corp.

UNSAFE MODULE Jv;

IMPORT Atom, AtomList, Ctypes, FilePosix, FileRd, FileWr, M3toC,
       OSError, OSErrorPosix, Rd, RTMisc, Text, Thread, Usocket, Wr;

REVEAL
  T = Public BRANDED OBJECT
        rd: Rd.T;
        wr: Wr.T;
      OVERRIDES
        init  := Init;
        close := Close;
      END;

PROCEDURE Init (t: T; pipeName: TEXT): T RAISES {OSError.E} =
  (* open Unix domain connection to server. *)
  VAR
    unaddr: Usocket.struct_sockaddr_un;
    fd    : INTEGER;
    strlen                             := Text.Length(pipeName);
  BEGIN
    unaddr.sun_family := Usocket.AF_UNIX;
    WITH string = M3toC.TtoS(pipeName) DO
      RTMisc.Copy(
        string, ADR(unaddr.sun_path[0]), strlen + 1 (* +1 for '\0' *));
    END;

    fd := Usocket.socket(Usocket.AF_UNIX, Usocket.SOCK_STREAM, 0);
    IF fd < 0 THEN OSErrorPosix.Raise(); END;

    WITH addr = LOOPHOLE(ADR(unaddr), UNTRACED REF Usocket.struct_sockaddr),
         addrlen = BYTESIZE(unaddr.sun_family) + strlen DO
      IF Usocket.connect(fd, addr, addrlen) < 0 THEN
        OSErrorPosix.Raise();
      END;
    END;

    WITH file = FilePosix.NewPipe(fd, FilePosix.ReadWrite) DO
      t.rd := NEW(FileRd.T).init(file);
      t.wr := NEW(FileWr.T).init(file, FALSE);
    END;
    RETURN t;
  END Init;

PROCEDURE Close (t: T) =
  BEGIN
    TRY
      Wr.Close(t.wr);
      Rd.Close(t.rd);
    EXCEPT
    | Thread.Alerted, Wr.Failure, Rd.Failure => (* skip *)
    END;
  END Close;
-- send and receiving stuff, assume BYTESIZE(CHAR) = byte --
TYPE
  LongArrayPtr =
    UNTRACED REF
      ARRAY [0 .. ((LAST(CARDINAL) DIV BITSIZE(CHAR)) - 1)] OF CHAR;
hack to get around type system. The horrible formula for the length of the array gives the longest possible array

PROCEDURE Send (t: T; buf: ADDRESS; nbytes: CARDINAL)
  RAISES {OSError.E, Thread.Alerted} =
  BEGIN
    TRY
      WITH chars = LOOPHOLE(buf, LongArrayPtr) DO
        Wr.PutString(t.wr, SUBARRAY(chars^, 0, nbytes));
      END;
      Wr.Flush(t.wr);
    EXCEPT
    | Wr.Failure (e) =>
        RAISE OSError.E(AtomList.Cons(Atom.FromText("Write"), e));
    END;
  END Send;

PROCEDURE Recv (t: T; buf: ADDRESS; nbytes: CARDINAL)
  RAISES {OSError.E, Thread.Alerted} =
  VAR nchars: CARDINAL;
  BEGIN
    TRY
      WITH chars = LOOPHOLE(buf, LongArrayPtr) DO
        nchars := Rd.GetSub(t.rd, SUBARRAY(chars^, 0, nbytes));
      END;
      IF nchars < nbytes THEN
        RAISE
          OSError.E(AtomList.List2(ServerFailure, Atom.FromText("Read")));
      END;
    EXCEPT
    | Rd.Failure (e) =>
        RAISE OSError.E(AtomList.Cons(Atom.FromText("Read"), e));
    END;
  END Recv;

BEGIN
  <* ASSERT BYTESIZE(CHAR) = BYTESIZE(Ctypes.char) *>
  (* dumb consistency check *)
  ServerFailure := Atom.FromText("Jv ServerFailure");

END Jv.

interface Usocket is in: