CAPABILITY
Purpose
A capability globally identifies and protects
an object.
Synopsis
#include <types.h>
struct Capability
{
Mailbox_Id server;
Word object;
Word rights;
Word check1;
Dwrd check2;
}
Structure
| 48 bits
|
16
bits
|
16
bits
|
16
bits
|
32 bits
|
| server
|
object
|
rights
|
check1
|
check2
|
-
server: identifies the server responsible
for implementing the object class methods;
-
object: identifies the object inside
the server;
-
rights: specifies the rights over
the object. A rights field equal to 0xFFFF designates a owner capability;
-
check1: firs 16 bits of a 48 bits
random number used to protect the object;
-
check2: last 32 bits of a 48 bits
random number used to protect the object.
Description
See Also
Mailbox_Id
Notes
The capability scheme described here has been
developed by Andrew Tanenbaum for the Amoeba system. It has been adopted
for the Aboelha system because it fulfill all of our requirements.