File type "door" on Solaris

[Jeffrey Parker]

Hello,

If you a "man ls" on any recent version of Solaris (for SPARC anyway),
you will see that the output of "ls -l" will give you a character "D"
in the leftmost (mode) part of the output which says that the file
currently displayed is a "door". There are a few in the /etc directory.

Anybody out there know what they are? I can find no documentation for them.
None of the Sys Admin books mention them, so I assume that they are a
"Solaris-ism".

Thanks in advance,

Jeff Parker

--Jeffrey W. Parker
--Unix System Administrator
--j...@xnet.com
-------------------------------------------------------------------------

[Mike Marshall]

Jeffrey Parker <j...@typhoon.xnet.com> writes:
>Anybody out there know what they are? I can find no documentation for them.

From http://www.sun.com/developer/devnews/fall96/doors.html:
(no longer available)

An Overview of Doors

A door is a "file" descriptor used to describe a procedure in a
process and optionally some additional state associated with the
procedure. Doors were initially designed as Spring object
descriptors used to encapsulate the state and capabilities of C++
objects. A process which obtains a door is free to pass it, along
with its capabilities, to other processes in the system.

hostname% man -k door
door_bind door_bind (3x) - bind or unbind the current thread with the door server pool
door_call door_call (3x) - invoke the function associated with a door descriptor
door_create door_create (3x) - create a door descriptor
door_cred door_cred (3x) - return credential information associated with the client
door_info door_info (3x) - return information associated with a door descriptor
door_return door_return (3x) - return from a door invocation
door_revoke door_revoke (3x) - revoke access to a door descriptor
door_server_create door_server_create (3x) - specify an alternative door server thread creation function
door_close door_close (3y) - close the door, were you born in a barn?
door_unbind door_bind (3x) - bind or unbind the current thread with the door server pool

[Ronald Geens]

Jeffrey Parker wrote:

> Hello,
>
> If you a "man ls" on any recent version of Solaris (for SPARC anyway),
> you will see that the output of "ls -l" will give you a character "D"
> in the leftmost (mode) part of the output which says that the file
> currently displayed is a "door". There are a few in the /etc directory.
>

> Anybody out there know what they are? I can find no documentation for them.

> None of the Sys Admin books mention them, so I assume that they are a
> "Solaris-ism".

Indeed, although I have heared of a version for Linux under construction (as so
many things in the Linux case).
The latest version of the Steven's Network Programming book describe the interface
though so you can find more information there. (the basic idea is to have a more lightweigth
RPC mechanism that only works within the same kernel and is thread based)

Ron.

[Peter Sundstrom]

Jeffrey Parker wrote in message <8ir0ai$ro7$1...@flood.xnet.com>...

>Hello,
>
> If you a "man ls" on any recent version of Solaris (for SPARC anyway),
>you will see that the output of "ls -l" will give you a character "D"
>in the leftmost (mode) part of the output which says that the file
>currently displayed is a "door". There are a few in the /etc directory.
>
>Anybody out there know what they are? I can find no documentation for
them.
>None of the Sys Admin books mention them, so I assume that they are a
>"Solaris-ism".

Perhaps it indicates a portal to a parallel universe.