SEKE 2012 Proceedings - Knowledge Systems Institute

sequence. Each t i θ i in the firing sequence is a test input if t i is
not a hidden event (Lines 5-8). Each predicate in M i is
corresponding to a test oracle if p is not hidden (Lines 11-13).
f e (t i (f o (V 1 ),…, f o (V k ))) means that each model -level actual
parameter V j of transition t i is first replaced with the
corresponding implementation-level parameter from object
mapping f o and then the implementation code for transition t i is
obtained from f e . f a (p(f o (V 1 ),…, f o (V k ))) means that each model -
level actual param eter V j of p is first replaced with the
corresponding implementation-level parameter from object
mapping f o and then the accessor code for transition t i is
obtained from event mapping f e .
Algorithm 3 below generates a C file, which contains
multiple pthreads for a nondeterministic test sequence.
Algorithm 3. Generate multi-threaded test code in C from a
nondeterministic test sequence
Input: test ID, nondeterministic test sequence ,, , MIM(ID, f o, f e, f a, l h, h)
Output: testCode file
Declare: f i is the thread function for F i(generated by Algorithm2)
1. begin
2. testCode ← h
3. for i=1 to n do
4. testCode ← testCode + thread declaration for r i
5. endfor
6. for i=1 to n do
7. fi ← call Algorithm 2 with F i and MIM
8. testCode ← testCode + f i
9. endfor
10. testCode ← testCode + signature of main function
11. testCode ← testCode + ”{”
12. testCode ← testCode + setup call if setup is defined
13. for i=1 to n do
14. testCode ← testCode + thread creation for r i
15. endfor
16. for i=1 to n do
17. testCode ← testCode + thread join for r i
18. endfor
19. testCode ← testCode + teardown call if is defined
20. testCode ← testCode + “}”
21. save test code to a file named after system ID + test ID
22. end
The code snippet below shows the test code for concurrent test
sequence , .
#include
pthread_t tidproducer;
void *producer(void * parm) {
pch = item[1];
printf("Producing %c ...\n", pch);
put(pch);
pch = item[2];
printf("Producing %c ...\n", pch);
pthread_exit(0);
}
void *consumer(void * parm) {
// thread declaration
// produce(1)
// produce(1)
// put(1)
// produce(2)
// produce(2)
gch=get();
// get
printf("Consuming %c ... \n", gch); // consume
}
main(int argc, char *argv[]) {
pthread_create(&tidproducer, NULL, producer, NULL);
pthread_join(tidconsumer, NULL);
}
Obviously, Algorithm 3 can be called to generate test code
for a set of non-deterministic test sequences, e.g., produced by
Algorithm 1.
V. CASE STUDIES
We have implemented our approach based on the M ISTA
tool. Our case studies focus on demonstrating that our approach
can generate concurrent test code from test models.
A. Bounded Buffer
Bounded buffer is a classical example for demonstrating the
synchronization problem of multi-threaded programming. It
involves two types of threads, producer and consumer, that
share a fixed-size buffer. A producer generates a piece of data,
puts it into the buffer, and starts again. A t the sam e time a
consumer consumes the data one piece at a time. Existing work
often focuses on the testing of given producer and consumer
programs together with the bounde r buffer (Strictly speaking,
producer and consumer are only one test for bounded buffer).
Our work, however, focuses on the testing of the bounded
buffer. We view producer and consumer programs as test cases
for the bounded buffer. As shown in Section IV, we use test
models to generate different kinds of producers and consumers.
For example, a concurrent test may have different number of
producers and consumers. The producer and consumer in one
test may have different numbers of calls to put and get.
B. ATM
ATM [5] is a client/server program for managing ATM
accounts, e.g., querying the current balance of an account,
depositing money to an account, and withdrawing money from
an account. The server program can accept requests from
different clients by using mu lti-threaded programming. The
multiple threads can access account data sim ultaneously. For
the ATM program, testing can be done from the client side. For
example, a test case can first deposit money to an account and
then withdraw money from the same account. Such traditional
test cases can be generated by the existing MISTA tool. In this
study, we focus on generation of concurrent tests with m ultiple
threads. Each thread sends requests to the server. D ifferent
threads may operate on the same account to check if th e server
fails to respond correctly.
For each case study, we were able to generate executable
pthread code for many concurrent tests. This has demonstrated
the technical feasibility. W e are currently applying the
approach to an industry project at Samsung.
VI. RELATED WORK
Our approach is related to code-based and specification -
based testing of concurrent programs and testing with Petri
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