def next_test_instruction(self):
if self.next_step % 2 == 0:
# provide a new input (step/2+1)-th input (starting with 1)
return Input(self.active_test(int(self.next_step / 2) + 1))
else:
return Output(
None) # here, this means that an output should be expected
def get_traces(self, boundary):
# check if values are already computed
if self.values_k_1 == None or self.values_k_2 == None or len(
self.values_k_1) != boundary or len(
self.values_k_2) != boundary:
# inputs are all natural numbers
inputs = xrange(1, boundary + 1)
# create the empty trace for k=1 and k=2 in the computation algorithm
self.values_k_1 = SimpleTrace(
[], boundary
) # Note that we do not use the boundary functionality of the trace here, because we generate the trace of the aprropriate size directly
self.values_k_2 = SimpleTrace([], boundary)
number_of_items = 0
for inp in inputs:
# add the current input
self.values_k_1.extend(Input(float(inp)))
self.values_k_2.extend(Input(float(inp)))
number_of_items = number_of_items + 1
if number_of_items >= boundary:
# We added enough values (note that the for-loop without the breaks would produce 2*boundary values)
break
# add the corresponding output
self.values_k_1.extend(Output(float(inp) * 1)) # o = i * 1
self.values_k_2.extend(Output(float(inp) * 2)) # o = i * 2
number_of_items = number_of_items + 1
if number_of_items >= boundary:
break
return [self.values_k_2, self.values_k_1]
def receive_output(self):
# get the output from the recordedTrace
next_symbol = self.recordedTrace.get_current_symbol()
# reassure that it is an output
if isinstance(next_symbol, Output):
# advance the internal symbol position of the recordedTrace to the next symbol
self.recordedTrace.advance_symbol()
return next_symbol
else:
# if the symbol is not an output, warn the user and return quiescence
print(
'Warning! DT requested an output although no output is available.'
)
return Output(None)
def get_symbol_from_string(self, str):
if str[0] == 'i':
# this is an input
# parse the value
number = float(str[1:])
return Input(number)
elif str[0] == 'o':
# we have an output
# parse the value
number = float(str[1:])
return Output(number)
else:
raise Exception('Unknown file format!')
def wrong_test_instruction(self):
if self.next_step == 2:
return Output(None)
else:
return self.next_test_instruction()
def advance(self):
# pick one of the three options of the algorithm
option = self.test_case_selection.get_next_option(self.history)
if option == TestCaseSelection.OPTION_PASS:
# the test is passed
return TestResult(TestResult.PASSED, self.history)
elif option == TestCaseSelection.OPTION_INPUT:
# get the next input from test case selection
next_input = self.test_case_selection.get_next_input(self.history)
# pass input to SUT and check if SUT provided an output in the meantime
system_output = self.system_under_test.pass_input(next_input)
if system_output != None:
# the input is cancelled, because the output generated by the SUT must be processed first.
# the new output may influence test case selection
# we add the output to the history
self.history.extend(system_output)
# Check if the output is accepted (this is the case, if no counter example can be found)
counterexample = self.output_verifier.check_output(
self.history)
if counterexample != None:
# the test failed, because we received an invalid output
return TestResult(TestResult.FAILED, self.history,
counterexample)
else: # system_output == None
# the input has been accepted, so we add it to the history
self.history.extend(next_input)
# return None to indicate that the test is neither passed nor failed
return None
elif option == TestCaseSelection.OPTION_OUTPUT:
# we wait for the next output or quiescence
system_output = self.system_under_test.receive_output()
if system_output == None:
# we observe quiescence
# we add the quiescence to the history
self.history.extend(Output(None))
# Check if quiescence is accepted (this is the case, if no counter example can be found)
counterexample = self.output_verifier.check_quiescence(
self.history)
if counterexample != None:
# the test failed, because quiescence is not allowed here
return TestResult(TestResult.FAILED, self.history,
counterexample)
else:
# we add the verified output to the history
self.history.extend(system_output)
# Check if the output is accepted (this is the case, if no counter example can be found)
counterexample = self.output_verifier.check_output(
self.history)
if counterexample != None:
# the test failed, because we received an invalid output
return TestResult(TestResult.FAILED, self.history,
counterexample)
# return None to indicate that the test is neither passed nor failed
return None
else:
raise Exception('Invalid option!')