From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 8 Jul 2015 20:46:52 -0400
Subject: Initial commit

---
 sys/gio/cursor/gtrdiscon.x | 66 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 sys/gio/cursor/gtrdiscon.x

(limited to 'sys/gio/cursor/gtrdiscon.x')

diff --git a/sys/gio/cursor/gtrdiscon.x b/sys/gio/cursor/gtrdiscon.x
new file mode 100644
index 00000000..5eba23f4
--- /dev/null
+++ b/sys/gio/cursor/gtrdiscon.x
@@ -0,0 +1,66 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<gio.h>
+
+# GTR_DISCONNECT -- Disconnect from a kernel subprocess.  To achieve an orderly
+# shutdown we process any outstanding XMIT or XFER requests, then transmit an
+# end of file (zero length record) to the kernel task when it reads from the
+# graphics stream.  The kernel should then shutdown and eventually we will
+# receive "bye" from the process.  We then call PRCLOSE to shutdown the
+# process for good.  Note: we do not expect anything but an XFER (read) request
+# on the graphics stream, but it seems prudent to do something reasonable if
+# some other request is received.
+
+procedure gtr_disconnect (pid, in, out, stream)
+
+int	pid			# process id of subprocess
+int	in, out			# command i/o streams of the subprocess
+int	stream			# graphics stream used by kernel
+
+pointer	sp, sp2, lbuf, buf
+int	pseudofile, nchars, junk
+bool	streq()
+int	getline(), read(), strncmp(), psio_isxmit(), prclose(), pr_findproc()
+errchk	getline, prclose, read, write
+
+begin
+	call smark (sp)
+	call salloc (lbuf, SZ_LINE, TY_CHAR)
+
+	while (getline (in, Memc[lbuf]) != EOF) {
+	    if (streq (Memc[lbuf], "bye\n") ||
+		strncmp (Memc[lbuf], "ERROR", 5) == 0) {
+
+		junk = prclose (pid)
+		break
+
+	    } else if (Memc[lbuf] == '!') {
+		# OS escape.
+		call proscmd (pr_findproc(pid), Memc[lbuf+1])
+
+	    } else {
+		call smark (sp2)
+
+		switch (psio_isxmit (Memc[lbuf], pseudofile, nchars)) {
+		case XMIT:
+		    call salloc (buf, nchars, TY_CHAR)
+		    nchars = read (in, Memc[buf], nchars)
+		    if (nchars > 0)
+			if (pseudofile == STDOUT || pseudofile == STDERR)
+			    call write (pseudofile, Memc[buf], nchars)
+
+		case XFER:
+		    call salloc (buf, nchars, TY_CHAR)
+		    if (pseudofile == STDIN)
+			nchars = read (pseudofile, Memc[buf], nchars)
+		    else
+			nchars = 0		# this is the EOF
+		    call psio_xfer (out, Memc[buf], nchars)
+		}
+
+		call sfree (sp2)
+	    }
+	}
+
+	call sfree (sp)
+end
-- 
cgit