DIPC.CONF(5)

NAME
dipc.conf - DIPC configuration file

DESCRIPTION
 This file, located in the /etc directory, is read by dipcd on startup to get some necessary information. The general format of the entries in this file is

    <var> = <value>.

 For more information, please refer to DIPC's documentation.
 Here are the recognized values for <var>:

this_machine
    The IP address of this machine, in w.x.y.z or in symbolic notation. If symbolic, dipcd will try to resolve the address on start-up. This entry should be present in the file. Don't use addresses like 127.0.0.1 or 'localhost' for this entry. Using 'dipc_auto_find' as the value for this entry will indicate to dipcd to use the hostname command to find the needed IP address.

referee
    IP address of the referee to whom this machine will refer, in w.x.y.z or in symbolic notation. If symbolic, dipcd will try to resolve the address on start-up. This entry should be present in the file. You could set this entry to the same valid IP address as 'this_machine'. Don't use 'dipc_auto_find', or addresses like 127.0.0.1, or 'localhost' for this entry.

transfer_mode
    If this is equal to 'segment', then DIPC will use a segment as the unit of shared memory management and transfer. 'Page' forces DIPC to use pages. The page size is determined by dipc_page_size entry in the dipc.conf file.

dipc_page_size
    If transfer_mode is 'Page', then this value is used as the size of the virtual page size managed and transfered over the network by DIPC, Otherwise it is not used. This value can be a multiple of the system's virtual memory page size.

inhibit_shm_signal
    If equal to 'yes', DIPC will not send a signal to readers or writers of a shared memory. 'no' causes the signals to be sent.

employer_referee_timeout
    The amount of time in seconds that the employer will wait for a reply from referee. This is the time a referee has to answer to requests. It is used whenever an employer wants to contact the referee. These include, searching for a IPC structure, and removing or deleting an IPC structure.

employer_shm_timeout
    The amount of time in seconds that the employer will wait for a reply from a shared memory manager. This is used when the employer wants to handle a shared memory read or write. If the number of processes accessing a shared memory simultaneously is large, then this time should be increased.

employer_worker_timeout
    The amount of time in seconds that the employer will wait for a reply from a worker. Its use includes the time allowed for remote procedure calls. So for example a wait for a semaphore (via a semop() function) should return within this time. This is different from the normal IPC case, where for example a semop() could not return for a very long time. In DIPC, as far as the employer is concerned, there is no way to distinguish between a system call that is not returning fast, and some problem in the remote machine or the network. This time out value should be adjusted for different applications. Remember that the above time-out applies only to requests from other machines, not the one on which the IPC structure was created. Processes on this machine can wait indefinitely.

shm_ak_timeout
    When a computer requests the contents of a shared memory, the responsible shared memory manager will directly or indirectly send it the contents, and then waits for an acknowledgment. This value gives the amount of time in seconds that the shared memory manager will wait for it.

referee_timeout
    After the referee sends the information about an IPC structure to a requesting machine, it will wait for this amount of time to receive a reply, to find out if the machine created an structure with the corresponding key or not.

shm_hold_timeout
    This gives the time quantum in split seconds, for the shm_man. It is used in scheduling machines who request to access the shared memory, and determines the minimum time that a computer can access the shared memory before it is given to someone else. It is not possible to disable this timeout in any way.

Positive time-out values indicate that you want the time-out to be used. A zero or negative value means that you don't want dipcd to use the time-out mechanism for that particular action. So you can control individual time-outs. As mentioned before, you can use the -t command line argument to disable the whole time-out mechanism, regardless of individual time-out values. The exception here is the shm_hold_timeout, which is always used. These entries can be omitted, in which case default values will be used.

EXAMPLE
this_machine = 191.72.3.0 #address of this machine referee = 191.72.3.0 # address of the referee. transfer_mode = Segment dipc_page_size = 8192 inhibit_shm_signal = No employer_referee_timeout = 55 employer_shm_timeout = 56 employer_worker_timeout = 300 shm_ak_timeout = 38 referee_timeout = 18 shm_hold_timeout = 0.6

FILES

/etc/dipc.conf - configuration file for dipcd

/etc/dipc.allow - access list used by dipcd

SEE ALSO
dipc(1), dipcd(8), dipcker(1), dicref(1), dipcshm(1), dipcx(1), dipc.allow(5), rsh(1), ipc(2)

BUGS
Please send all bug reports to this address:

linux-dipc@wallybox.cei.net