aclm_up() — Apollo

ACLM_$UP                          Domain/OS                           ACLM_$UP


NAME
     aclm_$up - assert subsystem manager rights

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/aclm.h>

     void aclm_$up(void)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/aclm.ins.pas';

     procedure aclm_$up;

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/aclm.ins.ftn'

           call aclm_$up

DESCRIPTION
     Aclm_$up asserts a process' rights to access an object in a protected
     subsystem until a corresponding call to aclm_$down is made.  Even a sub-
     system manager, which has the right to gain access to the protected
     objects, must call aclm_$up to assert its rights before it can actually
     use a protected object.  Calling aclm_$down deasserts a process' rights
     to a subsystem.

     A program should activate its rights as a subsystem manager for the
     minimum amount of time it will need them by using aclm_$up and aclm_$down
     to bracket high-level statements or functions for which privileged access
     is needed.  This ensures against inadvertent use of protected objects.

     Calling aclm_$up increments a counter in a process; calling aclm_$down
     decrements it.  Subsystem manager operations are enabled whenever the
     counter is nonzero.

     Calling aclm_$up obtains all the subsystem rights to which a process is
     entitled.  If a program that is not a subsystem manager calls aclm_$up,
     it produces no effect, but does not return an error.  Likewise, calling
     aclm_$down when subsystem manager rights are already deasserted has no
     effect.
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