Download Legion 1.8 Basic User Manual

June 28, 2001
Figure 4:
Legion 1.8 Basic User Manual
Context names referring to objects
context space
Root
objects
User1
/home/User1
User2
/home/User2
ContextA
Foo
ContextB
Fred
X
Bar
Bar2
Y
User3
/home/User3
ContextC
User4
/home/User4
ContextA
Foo
FooFoo
This example shows four different context paths pointing to two different objects. Three of the paths
point to object X: home/User1/ContextA/Foo and home/User1/ContextB/Fred are in
User1’s context space, and /home/User2/Bar is in User2’s context space. The fourth path,
/home/User3/ContextC/Foo, points to object Y.
You can share your context space with other Legion users, just as
Unix users can work in one another’s directories. You can also protect
individual objects or groups of objects against unauthorized use by a
specific user/object or a group.
Beyond the user-level grouping of individual context spaces, you can
link object groups in graph- or directory-based structure. Just as a
Unix directory tree or collection of hypertext documents provides a
logical means to organize information, context space provides a
structure for finding and organizing Legion objects. For example, to
find a host object running on an IBM SP2, you might logically start with
the /hosts context, then look in /ibm, then /sp2, where a list of host
objects running on SP2s could be found. This is like moving through a
set of directories to get to a /hosts/ibm/sp2 directory.
Objects contain in their state a root context (implicitly named /) that
provides each object with a base for absolute path names. The root
context's LOID is stored in a variable that can altered by the object at
runtime. Objects also contain in their state the current context’s LOID,
which provides the basis for relative context paths.
Basic User
page 19