Initial commit

1 files changed, 164 insertions, 0 deletions

diff --git a/sys/fio/filopn.x b/sys/fio/filopn.x
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<error.h>
+include	<ctype.h>
+include	<syserr.h>
+include	<config.h>
+include	<fio.h>
+include	<fset.h>
+
+# FILOPN -- Open a file on an installed device.  A file descriptor is
+# allocated and initialized.  If a new file is being opened, file clobber
+# (overwrite) checking is performed.  If the file exists but cannot be
+# accessed because it is open by another process, and file waiting is
+# enabled (usually in batch mode), the process is blocked until the file
+# becomes available.  If one attempts to "open" one of the files "STDIN",
+# "STDOUT", "STDERR", etc.  the fd of the appropriate standard file is returned.
+# Interrupts are disabled while the VFN database is open to protect the
+# database, ensure that that the lock on the mapping file is cleared, and to
+# ensure that the mapping file is closed.
+
+int procedure filopn (fname, mode, type, zopen_proc, device)
+
+char	fname[ARB]			# virtual file name
+int	mode				# access mode (ro,rw,apnd,newf,temp)
+int	type				# text or binary file
+extern	zopen_proc(), device()
+
+pointer	vp
+bool	standard_device
+int	ip, fd, dev_epa, junk, status, vfnmode
+
+pointer	vfnopen()
+int	fgetfd(), fstdfile(), vfnadd(), vfnmap(), locpr()
+errchk	fwtacc, seek, fclobber, fgetfd
+include	<fio.com>
+define	cleanup_ 91
+define	close_ 92
+define	abort_ 93
+
+begin
+	for (ip=1;  IS_WHITE (fname[ip]);  ip=ip+1)
+	    ;
+
+	# Do not bother to check access mode if reopening a standard
+	# stream.  If one attempts to write to STDIN or read from STDOUT,
+	# a suitable error message will be generated at that time.  If
+	# a standard file such as STDIN is reopened read-write but never
+	# written to, however, that is acceptable.
+
+	if (fstdfile (fname[ip], fd) == YES)		# standard stream?
+	    return (fd)
+
+	# Determine if "device" is a standard disk device, i.e., the driver
+	# TX or BF or the static file driver SF.  Clobber and filewait are
+	# only performed for disk files.
+
+	dev_epa = locpr (device)
+	standard_device = (dev_epa == zdev[TX_DRIVER] ||
+			   dev_epa == zdev[BF_DRIVER] ||
+			   dev_epa == zdev[SF_DRIVER])
+
+	# Perform clobber checking and waiting only for standard devices.
+	# If clobber is enabled and we are opening a new file, any existing
+	# file will be deleted.
+
+	if (standard_device && (mode == NEW_FILE || mode == TEMP_FILE))
+	    call fclobber (fname[ip])
+
+	# Allocate and initialize the file descriptor.
+	fd = fgetfd (fname[ip], mode, type)
+	call fseti (fd, F_DEVICE, dev_epa)
+	fp = fiodes[fd]
+
+	# Get OS pathname of file.
+	if (standard_device) {
+
+	    # Don't open VFN with write perm if file is readonly, else
+	    # lockout may occur on the mapping file.
+
+	    if (FMODE(fp) == READ_ONLY)
+		vfnmode = VFN_READ
+	    else
+		vfnmode = VFN_WRITE
+
+	    call intr_disable()
+	    iferr (vp = vfnopen (fname[ip], vfnmode))
+		goto abort_
+
+	    if (FMODE(fp) == NEW_FILE) {
+		iferr (junk = vfnadd (vp, FPKOSFN(fp), SZ_FFNAME))
+		    goto close_
+	    } else {
+		iferr (status = vfnmap (vp, FPKOSFN(fp), SZ_FFNAME))
+		    goto close_
+		if (status == ERR)
+		    iferr (call syserrs (SYS_FOPEN, fname[ip]))
+			goto close_
+	    }
+
+	    iferr (call vfnclose (vp, VFN_UPDATE))
+		goto abort_
+	    call intr_enable()
+
+	} else
+	    call strpak (fname[ip], FPKOSFN(fp), SZ_FFNAME)
+
+	# Open file.  If file exists on a standard device but cannot be
+	# accessed and "filewait" is enabled, wait for file to become
+	# accessible.
+
+	repeat {
+	    call zopen_proc (FPKOSFN(fp), FMODE(fp), FCHAN(fp))
+	    FDEVOPEN(fp) = locpr (zopen_proc)
+
+	    fp = fiodes[fd]
+	    if (FCHAN(fp) == ERR) {
+		iferr {
+		    if (standard_device) {
+			iferr (call fwtacc (fd, fname[ip]))
+			    call syserrs (SYS_FOPEN, fname[ip])
+		    } else {
+			call syserrs (SYS_FOPENDEV, fname[ip])
+		    }
+		} then
+		    goto cleanup_
+	    } else
+		break
+	}
+
+	# Get the device parameters (block size, file size, streamer, etc.)
+	iferr (call fgdev_param (fd))
+	    goto cleanup_
+
+	iferr {
+	    if (mode == APPEND)
+		call seek (fd, EOFL)
+	    else
+		call seek (fd, BOFL)
+
+	    # Save name of temporary file for automatic deletion at program
+	    # termination.
+	    if (mode == TEMP_FILE)
+		call fsvtfn (fname)
+	} then
+	    goto cleanup_
+
+	return (fd)
+
+cleanup_
+	call frtnfd (fd)
+	call erract (EA_ERROR)
+	return (ERR)
+
+
+	# Error recovery nasties for when the VFN is open.
+close_
+	iferr (call vfnclose (vp, VFN_NOUPDATE))
+	    ;
+abort_
+	call frtnfd (fd)
+	call intr_enable()
+	call erract (EA_ERROR)
+	return (ERR)
+end