1 files changed, 64 insertions, 0 deletions
diff --git a/sys/mtio/mtalloc.x b/sys/mtio/mtalloc.x
new file mode 100644
index 00000000..2e21be1c
--- /dev/null
+++ b/sys/mtio/mtalloc.x
@@ -0,0 +1,64 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<time.h>
+include	"mtio.h"
+
+# MTALLOCATE -- "Allocate" a tape drive by writing the lock file.  We do
+# not actually call the OS to physically allocate the drive; that is done
+# by our caller (e.g., xallocate, in etc$xalloc.x).  The lock file is no longer
+# used to gain exclusive access to the device; it is now used only to keep
+# track of the tape position after process termination.
+
+procedure mtallocate (mtname)
+
+char	mtname[ARB]			#I device name
+
+int	fd, junk
+pointer	sp, lockfile, mtowner, userid, timestr, device
+errchk	open, mtparse
+long	clktime()
+int	open()
+
+begin
+	call smark (sp)
+	call salloc (device, SZ_FNAME, TY_CHAR)
+	call salloc (lockfile, SZ_FNAME, TY_CHAR)
+	call salloc (mtowner, SZ_FNAME, TY_CHAR)
+	call salloc (userid, SZ_FNAME, TY_CHAR)
+	call salloc (timestr, SZ_TIME, TY_CHAR)
+
+	# Get name of lockfile used by the given device.
+	call mtparse (mtname, Memc[device], SZ_FNAME, junk, junk, junk, 0)
+	call mt_glock (mtname, Memc[lockfile], SZ_FNAME)
+
+	# Open lock file and write out unit, owner, time allocated, etc.
+	# Overwrite any existing lockfile.  We are called only after
+	# physically allocating the device at the host system level
+	# (and are not called if the device is already allocated), so this
+	# is safe.
+
+	iferr (call delete (Memc[lockfile]))
+	    ;
+	fd = open (Memc[lockfile], NEW_FILE, TEXT_FILE)
+
+	call cnvtime (clktime(long(0)), Memc[timestr], SZ_TIME)
+	call getuid (Memc[userid], SZ_FNAME)
+
+	call fprintf (fd, "# Magtape unit %s status %s user %s\n")
+	    call pargstr (Memc[device])
+	    call pargstr (Memc[timestr])
+	    call pargstr (Memc[userid])
+
+	# Assume initially that the tape position is undefined.  This will
+	# cause the tape to be rewound on the first open, and thereafter
+	# the position will be defined unless an i/o error occurs.
+
+	call fprintf (fd, "file = -1\n")
+	call fprintf (fd, "record = -1\n")
+	call fprintf (fd, "nfiles = 0\n")
+	call fprintf (fd, "tapeused = 0 Kb\n")
+	call fprintf (fd, "pflags = 0\n")
+
+	call close (fd)
+	call sfree (sp)
+end