1. PPT1: How failures come to be
CEN 4072
Software Testing
PPT1: How failures come to be
PPT and video are due: no later than August 31, 5:00 PM
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This template file is just an outline of the presentation
that you need to complete. Additional pages will
be necessary to fully explore the topic above.
Each page should contain adequate text as well
as illustrations. You are free to use all publically
available information (text as well as graphics) as long as
the sources are properly acknowledged.

2. Team members’ contributions
Member [name]:

3. Golden rules Content outline:
Software testing begins with careful design
Explanation and examples

4. Golden rules Content outline:
Software that cannot be tested is useless
Explanation and examples

5. Facts on debugging Content outline: Examples of software failures
Impacts of software failures

6. Facts on debugging Content outline:
Damages caused by software failures
Impacts on society

7. Facts on debugging Content outline: Facts on debugging
Costs, validation and improvements

8. The TRAFFIC principle Content outline: Track Reproduce Automate
Find origins
Focus
Isolate
Correct

9. From defect to failure Content outline:
A sequence of events causing the defect to become a failure
Explanation and illustration

10. Efficiency of testing Content outline:
How defects and failures are related?
Can testing show the absence of errors?

11. Efficiency of testing Content outline:
How infections and defects are related?
Explanation and illustration

12. Search in time and space
Content outline:
Search from defect to failure in time and space
Illustration and explanation

13. Search in time and space
Content outline:
Find transition from sane to infected
Illustration and explanation

14. Search in time and space
Content outline:
Search from defect to failure: the principles
Examples of the complexity (number of variables and references among them)

15. Sample program - main int main(int argc, char *argv[]) { int *a;
int i;
a = (int *)malloc((argc - 1) * sizeof(int));
for (i = 0; i < argc - 1; i++)
a[i] = atoi(argv[i + 1]);
shell_sort(a, argc);
printf("Output: ");
printf("%d ", a[i]);
printf("\n");
free(a);
return 0; }

16. Sample program - sort There is a bug somewhere (main or
static void shell_sort(int a[], int size) {
int i, j;
int h = 1;
do {
h = h * 3 + 1;
} while (h <= size);
h /= 3;
for (i = h; i < size; i++)
int v = a[i];
for (j = i; j >= h && a[j - h] > v; j -= h)
a[j] = a[j - h];
if (i != j)
a[j] = v; }
} while (h != 1);
There is a bug somewhere (main or
shellsort). Find it using the principles
below.

17. Find origins Content outline: Deduce value origins
Separate relevant from irrelevant

18. Search in time Content outline:
Observe a transition from sane to infected
Example

19. Observing a run Content outline:
Trace the execution for all variables for all steps of execution
Illustration in time and space

20. Specific observations
Content outline:
Observe the state at specific locations
Walk-through example

21. Specific observations
Content outline:
Find the transition from sane to infected
Example steps

22. Specific observations
Content outline:
Fix the defect
Regress or not to regress?

23. Finding causes Content outline:
Find the difference between infected and sane states
Search in time and space

24. Automated debugging: program slices
Content outline:
Separate the part of the program that is relevant to the failure
Explanation and illustration

25. Automated debugging: observing state
Content outline:
Stop the program to observe the entire state
Is this an option for large programs?

26. Automated debugging: watching state
Content outline:
Watch a part of the state to find changes during execution
Examples and usefulness

27. Automated debugging: assertions
Content outline:
Specify expected values and check for them
Do we really know the expected values?

28. Automated debugging: anomalies
Content outline:
What is an anomaly?
Examples

29. Automated debugging: anomalies
Content outline:
Observe the difference between passing the failing runs
Would this help with anomalies?

30. Automated debugging: cause-effect chains
Content outline:
How many chains are there?
Is it reasonable to find THE cause-effect chain?

31. Automated debugging: cause-effect chains
Content outline:
Identify which variable caused the failure
Note: causes are not necessarily errors!

32. Automated debugging: simplified input
Content outline:
Simplify the input so that each part contributes to the failure