converts between file system operations by applications
and messages on channels, as described in
Each attach that does not include a
produces a new instance: an empty directory owned
by the current user in which only files
may be created, and then only by
using a special internal interface.
Each such file initially has the same owner as the
directory, and permissions
(read-write for the owner only),
but the permissions can be changed by
is thereby set, the file becomes exclusive-use and can be opened by
only one process at a time.
The file length and
may also be set by
but are not interpreted by the system.
Files may be removed, directly using
or indirectly by opening them with mode
also removes the corresponding file when the last references
to the server's read and write channels have gone
(eg, on server exit).
may be given to name specific instances of
so that a new name space can bind in a service created in another.
Only the owner (original creator) of the instance may attach to it,
unless the mode of the service directory is changed
to have general access.