checking sequence generation using state distinguishing subsequences
DESCRIPTION
Checking Sequence Generation Using State Distinguishing Subsequences. Adenilso Simão*, Alexandre Petrenko Centre de recherche informatique de Montreal (CRIM) *On a leave from the Universidade de São Paulo. A-MOST’09 @ Denver, April 1st, 2009. Outline. Problem statement Previous work - PowerPoint PPT PresentationTRANSCRIPT
Checking Sequence Generation Using State Distinguishing Subsequences
Adenilso Simão*, Alexandre Petrenko
Centre de recherche informatique de Montreal (CRIM)
*On a leave from the Universidade de São Paulo
A-MOST’09 @ Denver, April 1st, 2009
2
Outline
Problem statement Previous work Contribution of this work Example Conclusion
3
Problem Statement
Given a specification FSM with n states Deterministic, Minimal, Complete
Given a black box implementation FSM in the fault domain All FSMs with at most n states
Generate a checking sequence To detect all non-equivalent
implementations
4
Key Issue
How to recognize states in the implementation State distinguishing subsequences
Same input, but with different outputs Different distinguishing capacities
5
Previous Work
Hennie, 1965 Seminal paper Problem setting Efficient method
Ad hoc Distinguishing sequence
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
6
Previous Work
Kohavi and Kohavi, 1968 Improves (Hennie, 1965) Variable length distinguishing sequence
Prefix of a sistinguishing sequence
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
7
Previous Work
Gonenc, 1970 A method for checking sequence
generation Graph based Distinguishing sequences Formalizes (Hennie, 1965)
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
8
Previous Work
Boute, 1974 Distinguishing sets
Also known as adaptive distinguishing sequence
Generalizes (Hennie, 1965)
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
9
Previous Work
Aho et al., 1991 Uses Unique Input/Output
Sequences (UIOs) Incomplete fault coverage
Optimization approach Rural Chinese Postman Problem
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
10
Previous Work
Ural et al., 1997 Builds on (Aho et al. 1991) Improves (Gonenc, 1970) State Recognition and Transition
Verification Uses distinguishing sequences
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
11
Previous Work
Hierons and Ural, 2002 Improves (Ural et al. 1997) Uses distinguishing sequences
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
12
Previous Work
Serdar and Kuo-Chung, 2002 Improves (Gonenc, 1970) Uses distinguishing sequences and UIOs
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
13
Previous Work
Chen el al. 2005 Improves (Ural et al., 1997) Avoids redundant transition verification
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
14
Previous Work
Yalcin and Yenigun, 2006 Improves (Ural et al., 1997) Uses distinguishing sequences and UIOs
Hierons and Ural, 2006 Improves (Hierons and Ural, 2002) Uses distinguishing sequences
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
15
Previous Work
Simao and Petrenko, 2008 (SP08) Different approach for state recognition
Confirmed sets (of sequences) Local optimization
Experimental results Uses distinguishing sets
SK
02
1960 1970 1980 1990 2000 2010
H6
5
KK
68
G70
B74
A+
91
U+
97
HU
02
HU
06
YY
06
SP
08
SP
09
C+
05
16
Contribution of this work
New possibilities for shortening checking sequences Output-confirmed sequence Convergence/divergence
Sequence confirmation and transition verification using confirmed sets Even if distinguishing sequence or UIO
is not applied in a given state
17
Contribution of this work
Generation Method Uses various distinguishing sequences
Distinguishing sets UIOs State identifier in a subset of states
Local optimization of transfer sequences
No global optimization Overlapping
18
Example
2
5
3
4
b/1
a/0 b/1
a/0
a/1
b/1
b/0
b/0
a/1
a/0
1
19
Example
Hierons and Ural, 2006 Checking sequence of length 64
Chen et al., 2005 Checking sequence of length 44
Simao and Petrenko, 2008 Checking sequence of length 43
Proposed method Checking sequence of length 36
20
Other Examples
Serdar and Kuo-chung, 2002 Checking sequence of length 80 Our method: 36
Yalcin and Yenigun, 2006 Checking sequence of length 26 Our method: 13
21
Future work
To integrate the proposed approach with other methods
To conduct experimental comparison
To find balance between local and global optimization
