OSF DCE Application Development Guide--Introduction and Style Guide

OSF DCE Application Development Guide—Introduction and Style Guide
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client client client
name
binding
server server
object object object
server
2: make contact1: find object 3: access object
5.2 Binding to an Object
The difference between, for example, reading a local file on a single machine and
performing the same read on a remote file in DCE is like the difference between reading
information from a phone book yourself and dialing an operator for the same
information. The remote operation requires the addition of another active entity that can
be requested to perform it, since you cannot. Associated with every piece of remote data
available on a network is a remote server to manage that data and make it available. The
user may not see the server; even the client may be unaware of it, but it is there.
The DCE documentation often speaks of ‘‘binding to an object.’’ In reality, clients can
bind only to servers, which then may be requested to perform operations on objects that
are under their management. However, it is possible for a server to put bindings into
namespace entries that are named for the objects that it manages. Furthermore, these
exported bindings can be tagged with object UUIDs in such a way that incoming remote
calls from clients can be applied by the server to the object whose name entry the
binding was read from (the details of this technique are described later in this chapter).
When an application uses this kind of binding model, it is reasonable to say that the
client is logically bound to the object, although it is physically always bound to the
server that manages the object.
5.3 Junctions
Namespace junctions are another example of the hidden server effect. The following
remote filename was discussed earlier:
/.../tinseltown.org/fs/doc/jones/app.gd/chap2.ps
There it was explained that doc/jones/app.gd/chap2.ps is an entry in DCE DFS’s own
namespace, while /.../tinseltown.org/fs is a DCE namespace entry. Suppose a user enters
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