| Software
DSM(2) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| • | read
access |
|||||||||||||
| • | check
local copy |
|||||||||||||
| • | if
there is no valid local |
|||||||||||||
| copy,
requests copy to |
||||||||||||||
| owner PE |
||||||||||||||
| • | write
access |
|||||||||||||
| • | check
ownership |
|||||||||||||
| • | if
this PE doesnft have |
|||||||||||||
| owner
ship, requests |
||||||||||||||
| ownership
to owner PE |
||||||||||||||
| • | send an
invalidation to |
|||||||||||||
| all
copy owner PEs |
||||||||||||||
| read |
| local copy? |
|
|
|
| send copy |
||
| (remote) |
||
|
|
|
| request copy |
||
| (local) |
||
| communication |
| owner? |
| no |
| no |
| yes |
| yes |
| invalidation |
| : communication
occurs |