Information Technology Reference
In-Depth Information
eBay
p
1
Order
Invoke
TPC
p
5
p
2
(UserID, SecretID)
Process
FetchToken
p
6
Token
p
3
p
7
Process
GetOrderData
(Token, OrderID, UserID)
p
8
OrderData
p
9
p
4
Figure 4.3
The SWF-net of the eBay service illustrated in Figure 4.2.
color set of p
5
. UserID
SecretID, which denotes the set of all
valid combinations of user id and secret id, is the color set of p
6
.
Token, which denotes the set of all possible token messages (different
from the control token in P
I
), is the color set of p
7
. Token
OrderID
UserID, which denotes the set of all valid combinations of
token, order id,anduser id, is the color set of p
8
. OrderData,which
denotes the set of all possible order data messages, is the color set
of p
9
.
Cð
p
5
Þ¼Cð
p
7
Þ¼Cð
p
9
Þ¼
Cð
p
6
Þ¼Cð
p
8
Þ¼þ
1and
1
Let us explain the color set used in this example. Suppose that
there are two users in this system, that is, UserID
{u
1
, u
2
}, and each
user has his/her own token and secret id. Therefore, we have Token
¼
¼
{tk
1
, tk
2
}, SecretID
{s
1
, s
2
}, in which tk
1
and tk
2
are the tokens of
u
1
and u
2
, respectively; s
1
and s
2
are the secret ids of u
1
and u
2
,
respectively. Suppose that there are two items to buy or we have two
types of orders, that is, Order
¼
¼
{o
1
, o
2
}, and correspondingly Order-
Data
{od
1
, od
2
}inwhichod
1
and od
2
are the full content of o
1
and
o
2
, respectively. Then UserID
¼
SecretID
¼
{(u
1
, s
1
), (u
2
, s
2
)} and
Token
OrderID
UserID
¼
{(tk
1
, o
1
, u
1
), (tk
2
, o
1
, u
2
), (tk
1
, o
2
, u
1
),
