SPSHED(8)
NAME
spshed - spool scheduler
SYNOPSIS
spshed [ options ]
DESCRIPTION
spshed is the spool scheduler process for the GNUspool spooler and
document management system.
To start GNUspool, spshed should be started. This should normally be
done using gspl-start(1), which restarts it and passes the appropriate
options. This may be put within the Operating System startup scripts.
Likewise to halt it, gspl-stop(1) should be invoked. This should be
put, using the -y option, in any system shutdown routines.
If you do need to kill spshed for any reason, first try kill(1) without
any -9 option. This will give spshed the opportunity to attempt to tidy
up any IPC facilities before shutting down.
Information, either in respect of other machines to connect to, or preexisting jobs and printers on the current machine, are read from the
files gnuspool.hosts and the spool directory respectively.
If a networked version of GNUspool is being run, then a "slave" spshed
process is spawned to monitor and process incoming network messages.
Incoming remotely-submitted jobs and API interfaces are handled via a
separate process xtnetserv(8), which is also invoked as appropriate by
gspl-start(1).
Appropriate log messages are written by spshed and other system
processes to a log file, spshed_reps. Be sure to check this file for
any error messages relevant to any problems you encounter.
FILES
gnuspool.hosts host names and descriptions
gnuspool.conf master configuration file
int-config message file
spshed_jfile job file
spshed_pfile printer file
spshed_reps error log file
spufile0 user data
charges0 user charges data
spmm_jobi job memory-mapped hash file
spmm_jobd job memory-mapped data file
spmm_ptrs printers memory-mapped file
spmm_xfer communication buffer memory-mapped file
ENVIRONMENT
- SPOOLDIR
- alternative location for spool directory.
- SPHELPDIR
- alternative location for help file directory.
- SPROGDIR
- alternative location for internal programs directory.
IPC FACILITIES
An IPC message queue, with key 0x58691000 and owned by "spooler", is
created by spshed and used to receive messages from user processes,
pass instructions to spd(8), and to pass internal messages from the
slave spshed process to the master.
Two shared memory segments are created to hold details of jobs and
printers. As the shared memory facility provides no facilities for
growth, then additional shared memory segments may be created if the
job and printer lists expand sufficiently and the original ones
deallocated.
The keys given to the shared memory segments start at 0x58691002 and
ascend upwards to 0x58691064 before wrapping around.
A further shared memory segment, with key 0x58692002 is created to hold
details of pending jobs before transfer to the main shared memory
segment.
Versions of spshed may use memory-mapped files rather than shared
memory. The files are held in the spool directory, by default
/var/spool/gnuspool, and have the names spmm_jobi, spmm_jobd, spmm_ptrs
and spmm_xfer.
A set of 5 semaphores, with the key 0x58691001 is created to interlock
access to the shared memory segments.
The presence or absence of these IPC facilities is used by spshed and
other programs to determine whether a previous copy of itself is
running. If spshed is abnormally terminated, it will probably be
necessary to delete these IPC facilities before spshed can be
restarted.
When printers are set running, spshed invokes an instance of spd(8) to
control each printer. Mail and attention messages are passed to
spmdisp(8) for processing.
INTERNET PORTS
spshed accepts and sends interconnections from other machines on TCP
port, passes the contents of spool files on a further TCP port, and
undertakes "probes" on a UDP port.
The port numbers are set up in the /etc/services file when GNUspool is
first installed.
SEE ALSO
gspl-pr(1), gspl-pq(1), gspl-puser(1), gspl-qdel(1), gspl-qchange(1), gspl-qlist(1), gspl-plist(1), gspl-charge(1), gspl-start(1), gspl-stop(1), gnuspool.conf(5), gnuspool.hosts(5), gspl-cjlist(8), gspl-cplist(8), dosspwrite(8), ripc(8), spd(8), spdinit(8), spmdisp(8), spwrite(8), gspl-spuconv(8), xtnetserv(8).
DIAGNOSTICS
spshed is invoked from system startup procedures or other programs such
as gspl-start(1). Thereafter it runs as a "daemon process" and
diagnostics are not written to any terminal but to the file
spshed_reps.
In the event of any problems this file should be examined.
COPYRIGHT
Copyright (c) 2009 Free Software Foundation, Inc. This is free
software. You may redistribute copies of it under the terms of the GNU
General Public License <http://www.gnu.org/licenses/gpl.html>. There
is NO WARRANTY, to the extent permitted by law.
AUTHOR
- John M Collins, Xi Software Ltd.