unregister_callback(9r) [osf1 man page]

unregister_callback(9r) 												   unregister_callback(9r)

NAME

       unregister_callback - General: Deregisters a configuration callback routine

SYNOPSIS

       int unregister_callback(
	       void (*function) (),
	       int point,
	       int order,
	       ulong argument );

ARGUMENTS

       Specifies the name of the routine that you want to deregister.  You must have previously registered this callback routine by calling regis-
       ter_callback.  Specifies the execution point at which the kernel calls the callback routine previously registered by calling register_call-
       back. The execution point you pass to this argument must match the value you passed to the point argument in the call to register_callback.
       Specifies the order value that you specified in a previous call to register_callback.  Specifies an argument that you want  the	kernel	to
       pass to the callback routine that you previously registered by calling register_callback. The argument you pass to this argument must match
       the value you passed to argument in the call to register_callback. You would pass the integer constant 0L if you passed this in the  previ-
       ous call to register_callback to indicate there is no argument.

DESCRIPTION

       The  unregister_callback  routine deregisters a kernel module's configuration callback routine. The kernel module previously registered its
       routine or routines by calling the register_callback routine. The values you pass to unregister_callback must be the same ones  you  previ-
       ously passed to register_callback to deregister a specific routine. Kernel modules call unregister_callback to deregister the callback rou-
       tine when it is no longer needed.

       A kernel module typically calls unregister_callback when it encounters a fatal error during static or  dynamic  configuration.  The  cfgmgr
       framework  executes  callback routines scheduled to run after single-user mode each time the system goes from multiuser mode to single-user
       mode and back to multiuser mode. You should unregister any callback routines if you do not want this to occur.

NOTES

       The kernel maintains an internal callback list that stores the values you pass to the register_callback	routine.  These  callbacks  remain
       registered until the user removes them.

       The  unregister_callback  routine searches through the callback list for the specified callback routine, the specified point, the specified
       order, and the specified argument and removes that routine from the list.

RETURN VALUES

       Upon successful completion, the unregister_callback routine returns the value ESUCCESS.

       Otherwise, unregister_callback returns the following error constant, defined in /usr/sys/include/sys/errno.h: The value you passed  to  the
       point  argument	is  outside  the minimum and maximum range.  The callback you specified to be removed does not exist in the callback list.
       The callback you specified to be removed does not exist in the callback list.

FILES

SEE ALSO

       Routines: register_callback(9r)

															   unregister_callback(9r)

register_callback(9r)													     register_callback(9r)

NAME

       register_callback - General: Registers a configuration callback routine

SYNOPSIS

       int register_callback(
	       void (*function) (),
	       int point,
	       int order,
	       ulong argument );

ARGUMENTS

       Specifies  the name of the routine that you want called at a later time.  Specifies the dispatch point at which the kernel calls this call-
       back routine. The kernel passes the value associated with this dispatch point to the kernel module's callback routine  when  it	calls  it.
       Specifies  the order in which you want callback routines registered for the same dispatch point to be executed. The kernel passes the value
       associated with this order to the kernel module's callback routine when it calls it.  You use this argument to control the order of  execu-
       tion of multiple callback routine within each dispatch point. The register_callback routine executes a kernel module's callback routine for
       the same dispatch point in increasing numerical order of the value specified in the order argument.  Specifies an argument  that  you  want
       the  kernel  to pass to the kernel module'scallback routine when the kernel calls it. You pass the integer constant 0L to indicate that you
       do not want to pass an argument.

DESCRIPTION

       The register_callback routine registers a kernel module's callback routine. The kernel calls a kernel module's callback routine when execu-
       tion  reaches  the point specified in the point and order arguments. The kernel passes the values specified in the point and argument argu-
       ments to the kernel module's callback routine. Kernel modules implement one or more callback routines  to  handle  the  different  dispatch
       points in the boot path.

       The dispatch point constants you can pass to the point argument are defined in the /usr/sys/include/sys/sysconfig.h file. The following ta-
       ble lists the dispatch point constants that kernel modules can use: The dispatch point is hardware  preconfiguration.  Tasks  that  do  not
       require	completion  of	hardware configuration can be performed at this dispatch point.  The dispatch point is hardware postconfiguration.
       Tasks that require completion of hardware configuration can be performed at this dispatch point.  The dispatch point is	root  file  system
       available. Tasks that require completion of the root file system mount operation can be performed at this dispatch point.

       The  order constants you can pass to the order argument are defined in the /usr/sys/include/sys/sysconfig.h file. The following table lists
       the order constants that kernel modules can use: This callback routine is registered at the lowest priority.  Typically, you pass this con-
       stant  with an appropriate offset. The kernel executes callback routines registered at this priority last.  This callback routine is regis-
       tered at the highest priority.  Typically, you pass this constant with an appropriate offset. The kernel executes callback routines  regis-
       tered at this priority first.

NOTES

       The  kernel  maintains  an  internal callback list that stores the values you pass to the register_callback routine. These callbacks remain
       registered until the user removes them.

       Only statically configured kernel modules need to implement callback routines. Thus, only statically configured kernel modules need to call
       the register_callback routine.

       You  typically call the cfgmgr_get_state routine to determine if the kernel module is in the dynamic configuration state or the static con-
       figuration state.

RETURN VALUES

       Upon successful completion, the register_callback routine returns the value ESUCCESS.

       Otherwise, register_callback returns one of the following error constants defined in /usr/sys/include/sys/errno.h: The system limit on  the
       maximum	number	of  callback requests was exceeded. To change the maximum number of callback requests, set the new value for the boot-time
       tunable parameter max_callbacks in the cm subsystem (located in the /etc/sysconfigtab database) and reboot the  system.	You  can  use  the
       sysconfigdb utility to accomplish this task.  The value you passed to the point argument is outside the minimum and maximum range.

FILES

SEE ALSO

       Kernel routines: cfgmgr_get_state(9r), unregister_callback(9r)

															     register_callback(9r)