Chapter 8 Reactis Simulator
Simulator provides an array of features — including single- and multi-step
forward and backward execution, breakpoints, simulations driven by Tester-generated
test suites, and interactive simulation — for simulating your source
code. The tool also allows visual tracking of coverage data and the values data
items assume during simulation.
|Figure 8.1: The Reactis Simulator toolbar.|
Figure 8.1 contains an annotated screen shot of the
the Simulator toolbar. Some of the buttons and
menus on the leftmost part of the window have been elided;
Chapter 4 contains descriptions of these items.
The next section describes the labeled items in
Figure 8.1, while the section following discusses
the menu entries related to Simulator. The subsequent
sections discuss the different modes for generating inputs during
simulation, the ways to track data values, how to monitor code coverage,
the importing and exporting of test suites, and the different code
highlighting styles used by Simulator.
8.1 Labeled Window Items
Disable Reactis Simulator.
Enable Reactis Simulator.
Clicking this button resets the simulation; the code execution is returned to the
start state, and coverage information is appropriately reset.
Clicking this button causes the simulation to take n steps back,
where n is specified by window item 15.
Coverage information is updated appropriately upon completion
of the last backward step.
Clicking this button causes the simulation to take one step back.
Coverage information is updated appropriately.
Step backward to the point just before the current function was called.
Step backward one statement. Any function calls performed by the statement are
Step backward one statement. If the statement performed any function calls,
stop at the end of the last function which was called.
Clicking this button executes a single C statement, stepping into a function
when at a function call.
The button is disabled during fast simulation and reverse simulation.
When paused at a function call, clicking this button steps over the function
(executes the function and pauses at the following statement).
Step out of the currently executing function.
Clicking this button causes the simulation step to advance forward
by one full step; that is, values are read on the harness inputs,
the program’s response is computed and values are written to the harness
outputs. If a step has been partially computed,
then execution picks up with the current partially
computed step and continues until the end of the step, at which point
values are written to the harness outputs.
When paused, clicking this button causes n forward simulation steps to be
taken, where n is specified by window item 15. The diagram in
the main panel is updated
during simulation to reflect the currently executing code. When
Coverage -> Show Details is selected, coverage targets
will change from red to black as they are covered during the
simulation run. If the end of the current test or test suite is
reached or you click the Run/Pause button again (window
item 13), then simulation stops at the end of
the current simulation step.
Clicking this button causes n simulation steps to be executed, where
n is specified by window item 15.
The diagram in the main panel
is not updated while the
in progress but is updated when simulation halts. If the end of
the current test or test suite is reached then simulation halts.
When a fast simulation is running, clicking this button pauses the
simulation and the end of the currently executing step.
This window item determines how many steps are taken when buttons
corresponding to window
items 4, 13 ,
or 14 are clicked. When the
Source-of-Inputs Dialog (window item 16) is set to a
test or test suite, the number of steps may be set to 0 to indicate
that the entire test or test suite should be executed.
The Source-of-Inputs Dialog determines how input values
are computed during simulation. See Section 8.4
Clicking this button causes a new, empty test suite to be
created. The name of the .rst file containing the suite is
initially “unnamed.rst” and is displayed in the title bar of
the Reactis for C window.
Clicking this button displays a dialog
for selecting a test-suite (.rst file)
to be loaded into Simulator. After it is loaded, the test
suite’s name is displayed in the title bar, and the tests are listed
in the Source-of-Inputs Dialog (window item 16).
Clicking this button causes the current test suite to be saved.
- View Reactis for C help.
- The hierarchy panel (not shown explicitly) supports the
navigation of the project, as described in
Section 4.1. It shows the root build
file (.rsm file) at the top, and the C files and libraries below.
- The main panel displays the contents of the
C or .rsm file currently selected in the hierarchy panel. You may
interact with the panel in a number of different ways using the
mouse. These include hovering over items in the code
(e.g. variables, function names, macros) or right-clicking in
various parts of the panel. The following mouse operations are
available when Simulator is enabled:
- Right Clicking...
Causes different pop-up menus
to be displayed. The contents of the menus vary based on
where the click occurs and whether or not Simulator is
enabled. A summary of the menu items available when
Simulator is enabled follows 2. For descriptions of
the menu entries available when Simulator is disabled, see
|Menu Entries (when Simulator is enabled) |
Global variable or static local variable
Add To Watched
- Add item to watched variables list (see section 8.5.1).
- Open Scope
- Display item in scope (see section 8.5.2).
- Open Distribution Scope
- Display item in distribution scope (see section 8.5.3).
- Add To Scope
- Add item to previously opened scope. This item only appears
when other scopes are open.
Decision coverage target
View Coverage Details
- Display dialog containing detailed coverage information
for the decision (i.e. status of decision, condition, and MC/DC targets).
Open Difference Scope
- This menu item is enabled when a test suite is loaded.
It opens a scope which displays the differences between the output value computed by the program
under test and the output value stored in the test suite. See Section 8.5.4
In the line number bar to the left of the main panel.
- Enable or disable breakpoint for the line.
- Double Clicking...
in the line number bar to the left of the main panel toggles a breakpoint for the line.
- on any other item opens a separate window which contains the same information displayed
when hovering on that item. This is useful when the information in
in the hover window is clipped due to excessive length.
Except for the documented exceptions related to editing
.rsh files 3,
the menus described in Section 4.2 work in the
same manner when Simulator is enabled. The following additional
menu items are also active when Simulator is enabled.
- The following entries become enabled when
Simulator is “on”.
Show Watched Variables.
- Toggle whether or not watched-variable list is displayed. The default
is not to show them; adding to the list automatically
causes the list to be displayed.
- Clear Watched Variables.
- Remove all items from the
- Open Difference Scopes...
- Open a difference
scope on one or more harness outputs. This item is only
enabled when the input source is a test suite. See Section 8.5.4
- Close All Scopes.
- Close all open scopes.
- Open Scope (Signal Group)
- Open a scope on a signal group.
A signal group is created by clicking the save button
) in a scope to save the current configuration of the scope
as a signal group (set of signals along with the scope settings for
- Delete Signal Group
- Delete a signal group.
- Save Profile as...
Save the current view profile under a new name. The view profile
contains the currently opened scopes and watched variables.
Profiles are saved in with the .rsp suffix.
- Load Profile...
- Load a different view profile
(.rsp file ). This will automatically open all scopes and watched variables
stored in the profile.
- Simulate menu.
- The following entries are available when
Simulator is enabled.
- Enable or disable Simulator.
When disabled, Simulator behaves as a source code viewer; that is,
the code can be viewed but simulation capabilities are disabled.
- Fast Run with Report...
- Execute a fast simulation
simulation and produce a report. See Section 8.3 for details.
- Fast Run.
- Same as window item 14.
- Same as window item 13.
- Same as window item 12.
- Step Into.
- Same as window item 9.
- Step Over.
- Same as window item 10.
- Step Out Of.
- Same as window item 11.
- Stop a fast or slow simulation run.
- Reverse Step Into.
- Same as window item 8.
- Reverse Step Over.
- Same as window item 7.
- Reverse Step Out Of.
- Same as window item 6.
- Same as window item 5.
- Fast Back.
- Same as window item 4.
- Same as window item 3.
- Clear Breakpoints.
- Removes all breakpoints.
- Set Animation Delay...
- When running a slow simulation,
this value specifies the duration of the pause between the
evaluation and highlighting of different statements.
- Update Configuration Variable...
- Initiates a dialog for
changing values of configuration variables, which are global or
static local variables whose values can only change between
tests/simulation runs (but not during a test/simulation run). The
simulation must be reset to the start state (by clicking the reset
, window item 3) before the
value of a configuration variable may be updated. Note also that
whenever inputs are read from a test, the configuration variable
values from the test will be used. In other words, manual updates
to a configuration variable using this menu item will only have
effect when in random or user input mode.
- Test Suite menu.
- Same as window item 17.
- Same as window item 18.
- Same as window item 19.
- Save and Defragment.
- Removing tests from a test suite can
cause the test suite to become fragmented, meaning that space within
the file becomes unused. Reactis will reuse those gaps when you add tests.
Selecting this menu item will save the current test suite and reorganize
it, removing all gaps.
- Save As...
- Save current test suite in an .rst file . A
file-selection dialog is opened to determine into which file the test
suite should be saved.
- Import tests and add them to the current test suite.
Importing is described in more detail in Section 8.7.2.
- Export the current .rst file in different formats.
Exporting is described in more detail in Section 8.7.1.
- Launch Reactis Tester.
See Chapter 9 for details.
Create a new test suite by simulating the current code using inputs from the
current test suite, but recording values for outputs generated
by the code. This feature is described in Section 8.8.
- Open a file selection dialog, and then
launch the Test-Suite Browser on the selected file.
See Chapter 11 for details.
- Browse current...
- Launch the Test-Suite Browser on the
currently loaded test suite. See Chapter 11
- Add/Extend Test.
At any point during a simulation, the
current execution sequence (from the start state to the current state)
may be added as a test to the current test suite by selecting this menu item.
After the test is added it will appear in the Source-of-Inputs Dialog (window
item 16). Note that the new test will not
be written to an .rst file until the current test suite has been saved
using window item 15 or the Test Suite -> Save menu item.
- Remove Test.
- Remove the current test from the current test suite.
Note that the test will not be removed from the .rst file until the
current test suite has been saved using window item 19 or the
Test Suite -> Save menu item.
- Compare Outputs.
- Specify whether or not Simulator should
compare the simulation results against the results contained in the
test suite being executed. When enabled if a difference is detected
then the difference between the computed value and the value stored
in test suite is reported in a warning.
- Coverage menu.
The Coverage menu contains the following entries. Details about the
different coverage objectives may be found in
Chapter 7. The coverage information available from
the various menu items is for the current simulation run. If a test
suite is being executed, the coverage data is cumulative.
All targets covered by the portion of the current test executed
so far, plus those targets exercised in previous tests are listed as
- Open the coverage summary dialog shown in
- Show Details.
- Toggle the reporting of coverage information
by coloring, underlining, or over-lining code elements in the main panel.
- Show Report.
- Start the Coverage-Report Browser.
See Chapter 12 for details.
- Decisions, Conditions, Decisions, MC/DC, MCC,
Boundaries, User-Defined Targets, Assertion Violations, C Statements.
Each of these menu entries corresponds to one of the coverage
metrics tracked by Reactis and described in
Chapter 7. When a menu entry is selected and
Show Details is selected, any uncovered target in the
corresponding coverage criterion will be colored.
- Select All.
- When Show Details is selected, show
coverage information for all metrics.
- Deselect All.
- When Show Details is selected, show
no coverage information.
- Highlight Unreachable Targets.
- When Show Details is
selected, color unreachable targets. A target is
unreachable if it can be determined that the target will never be
covered prior to simulating the code.
The analysis used is conservative: marked
items are always unreachable, but some unmarked items may also
8.3 Creating Test Execution Reports
Fast Simulation Run with Report executes all tests within the current
test suite and produces a report which lists all runtime errors
(divide-by-zero, overflow, memory errors, missing cases, assertion
violations, etc.) and significant differences between output values stored in the test
suite and those computed by the program under test.
|Figure 8.2: The Reactis Test Execution Report Options dialog
is used to select the items which appear in a test execution report.|
When Simulate -> Fast Run with Report... is selected, the dialog shown in
Figure 8.2 will appear. This dialog is used to
select the items which will appear in the report. The following items are
labeled in Figure 8.2:
The Report Options panel is used to select optional report items,
such as the date, pathnames of input files, etc.
- When Include coverage report is selected in the
Report Options panel,
the Coverage Metrics panel can be
used to select which coverage metrics are
included in the test execution report.
There are three choices for each metric:
Note that due to dependencies
between metrics, some combinations are not allowed. For example,
Summary & Details cannot be selected for Condition targets
unless Summary & Details is also selected for Decision targets.
Summary & Details.
Targets of the metric will appear in both the coverage summary and coverage details
sections of the report.
- Summary Only.
Targets of the metric will appear in the coverage summary only.
Targets of the metric will be omitted from the report entirely.
- The Output Format panel lets you choose between HTML and XML output formats.
There is also an option to preview the results before saving the report.
- The Difference limit prevents reports for test runs with many
output differences from becoming excessively long. Once the limit is reached,
output differences are still counted but no details are included in the report.
- The Output panel determines where the report will be saved.
When the output format is HTML, you can choose to save the results for each
test in a separate file instead of generating a single file which contains
the entire report.
- Clicking on this button opens the help dialog.
- When you are satisfied with the selected report options, clicking on this
button will close the dialog and start the simulation run.
- Clicking on this button will close the dialog without initiating a simulation
|Figure 8.3: A test execution report can be generated by
loading a test suite in Simulator and selecting Simulate -> Fast Run
Once the simulation run begins, it does not stop until all tests have
During each test, if a runtime error is encountered,
the remaining steps of the test are skipped and Simulator continues
execution with the following test. After the last test is executed,
a window containing the test execution report will appear,
as shown in Figure 8.3.
An HTML version of the
report can be saved by clicking the Save button in the report window.
An HTML test execution report will contain some or all of the following sections,
depending on which options are selected:
A report header listing the data, input files, Reactis version, etc.
- A test summary listing the tests/steps which were executed and the
number of errors and differences detected for each test. Non-zero error
and difference totals can be clicked-on to jump to a detailed description
of the error or difference.
- The tolerance used to test the value of each output and test point.
- A list of test details. For each test, includes the details for
each error and difference that occurred, and plots of test data. The
plots for a test are hidden by default, but they can be viewed by either
clicking on the ± to the left of the signal name, or by clicking on Open all.
See section 8.3.1 for details.
- The model hierarchy. The name of each member of the hierarchy
can be clicked on to jump to the coverage details for that member.
- Coverage details for each component of the model. The coverage details
for a model component begin with a summary of the local and cumulative coverage,
followed by details for each metric. The details for a metric
show, for each target, whether or not the target was covered,
and if the target was covered, the test step when coverage occurred.
The contents of this section are identical to a coverage report
8.3.1 Test Data Plots
|Figure 8.4: An output plot from a test execution report.|
Figure 8.4 shows a typical plot from a test
execution report. Test data (inputs, outputs, or test points) are plotted
with the simulation time on the x-axis and the data value(s) on the
y-axis. For outputs and test points, two values are shown: the test value
(green), and the computed value (blue). The test value is the value stored
in the test being executed for the output. The computed value is the value
computed by the model for the output while executing the test. The
acceptable tolerance between the two values is shaded yellow. Regions where
the difference between the two signals is larger than the tolerance are
Plots can be inspected when viewed from within a web browser or the
preview dialog. The current focus of inspection is indicated by the intersection
of two gray dashed lines. The focus can be moved either by the mouse, or the
left and right arrow keys on the keyboard. Pressing S will move the focus
to the start of the plot, and pressing E will move the focus to the end.
There are six values 4
displayed at the top of the plot for the current focus. These are (1) the
step number, (2) the simulation time, (3) the test value (y value of green
line), (4) the computed value (y value of blue line), (5) the difference
between the test value and the computed value, and (6) the maximum
difference between the test and computed values which is tolerated. These
six values are updated whenever the focus is moved.
8.4 Specifying the Simulation Input Mode
|Figure 8.5: The Source-of-Inputs Dialog enables you to
specify how Simulator computes input values.|
Reactis Simulator performs simulations in a step-by-step manner: at each
simulation step values are generated for each input, and resultant
output values are reported. You control how Simulator
computes input values using the Source-of-Inputs Dialog (window item
16 in Figure 8.1) shown in
This dialog always includes the
Random Simulation and User Guided Simulation entries; if a test
suite has been loaded, then the dialog includes an entry for each test and
the All button becomes enabled. The dialog is used to specify
how input values are generated as follows.
- For each input, Reactis for C randomly selects a value from
the set of allowed values for that variable, using type and probability
information contained in the associated .rsh file . See
Chapter 6 for a description of how to enter this
information using the Reactis Harness Editor.
- User Guided Simulation.
- You determine the value for each input using the
Next Input Value dialog, which appears when the User Guided Simulation
entry is selected. See Section 8.4.1 below for more
information on this mode.
- Individual Tests.
- When a test suite is loaded, each test in
the suite has a row in the dialog that contains a test number,
a sequence number, a name and the number of steps in the test.
Selecting a test and clicking on Ok
will cause inputs to be read from
- Subset of Tests.
- You may specify that a subset of tests
should be run by holding down the control key and clicking on each
test to be run with the left mouse button. The tests will be run
in the order they are selected. As tests are selected the sequence
number column is updated to indicate the execution order of the
tests. When a new test is started, the code execution is reset to its
starting configuration, although coverage information is
not reset, thereby allowing users to view cumulative
coverage information for the subset of tests.
- All Tests.
- Clicking the All button in the lower left
corner specifies that all tests in the suite should be executed
one after another. The tests are executed sequentially. When a new
test is started, the code execution is reset to its starting configuration,
although coverage information is not reset, thereby
allowing you to view cumulative coverage information for the
entire test suite. Section 8.4.2 contains more
information on this mode.
You can change the sorting order of the tests in the table by clicking
on the column headers. For example, to sort the tests by the number
of steps, simply click on the header of the Steps column. Clicking
again on that header will sort by number of steps in descending order.
You may also use the Source-of-Inputs Dialog to change the name of a
test. To do so, select the test by clicking on it, then click on the
name and, when the cursor appears, type in a new name.
8.4.1 User Input Mode
When the User Guided Simulation mode is selected from the
Source-of-Inputs dialog, you provide values for inputs at each
execution step. This section describes how this is done.
|Figure 8.6: The Next Input Values dialog lets you control
the simulation by specifying the next value for inputs (item 4) and
clicking the stepping buttons (item 10).|
To enter the user-guided mode of operation, select User Guided
Simulation from the Source-of-Inputs dialog (window item 16 in
Upon selecting user-guided mode, a Next Input Values
dialog appears, as shown in Figure 8.6, that allows
you to specify the input values for the next simulation step.
Initially, each top-level input of the model
has a row in the dialog. You can remove inputs from the dialog or add
outputs, test points, and configuration variables by clicking the gear
) in the toolbar of the Next Input Values dialog.
Each row in the dialog contains 6 items (labeled 1-6 in Figure 8.6).
The toolbar for the dialog contains items 7-13. The elements of the dialog work
- The name of an item (input, output, test
point, or configuration variable).
- This check box toggles whether the item is included in a scope
displaying a subset of the signals from the
Next Input Values dialog.
- This pull-down menu has two entries that determine
how the next value for the input is specified:
- Randomly select the next value for the input
from the type given for the input in the .rsh file.
- Specify the next value with the text-entry box
in column four of the panel.
- If the pull-down menu in column three is set to “Entry”,
then the next input value is taken from this text-entry box.
The entry can be a concrete value (e.g. integer or floating point
constant) or a simple expression that is evaluated to compute the
next value. These expressions can reference the previous values
of inputs or the simulation time. For example, a ramp for input
drag can be specified by pre(drag) + 0.0001. A sine wave can be
generated by sin(t) * 0.001.
For the full description of the expression notation see
Section 18.104.22.168 below.
- If the pull-down menu in column three is set to “Entry”,
then clicking the history button (labeled H) displays
recent values the input has assumed. Selecting a value from the list
causes it to be placed in the text-entry box of column four.
- The arrow buttons in this column enable scrolling through
the possible values for the input. The arrows are available
for inputs or configuration variables:
having a base type of integer, boolean or fixed point; or
- having a base type of
either a resolution or subset of values constraint.
- When you enter a search string in this box, Reactis displays
only the rows for items whose names contains the given search string.
- When you check this box, all signals in the
Next Input Values dialog are plotted in a scope. When you uncheck
this box, all signals are removed from the scope and no scope is
- This pull-down menu sets the mode for all inputs at once to either
“Random” or “Entry.”
- These buttons control the simulation stepping exactly as they do in
the top-level main Simulator window.
- The entry in this box is a positive integer which specifies how many
steps to take when clicking one of the stepping buttons that triggers
multiple steps (e.g. fast simulation button).
- Open a dialog to select the set of signals (inputs, outputs, test points,
configuration variables) to be included in the Next Input Values dialog.
- Save the current configuration of the Next Input Values dialog
for future use or load a previously saved configuration.
When “run fast simulation” (window item 14 in
Figure 8.1) is selected, the input value specifications
in the Next Inputs Values dialog are used for each step in the simulation
Syntax of Next Input Value Expressions
The value an input should assume in the next simulation step can be
specified from its row by selecting Entry in column 3 and then
entering an expression in the box in column 4. We now describe the language
used to define an expression.
Assume foo is an input. Then the following examples demonstrate some possible
expressions to specify the next value of foo.
|Expression||Value foo will have in next step |
|pre(foo)||The value foo had in the previous step |
|pre(foo,2)||The value foo had two steps back |
|pre(foo) + 1||Add 1 to the value of foo in the previous step |
|pre(u)||Shorthand denoting the value of foo in the previous step|
|t||The current simulation time |
|sin(t)||The sine of current simulation time (i.e. generate a sine wave)|
The complete syntax of a next input value expression NIV is specified by
the grammar shown in Figure 8.7.
| NIV||:||numericConstant | |
| |||||inputName||Name of an input (must be within |
|Shorthand for current input (must be within |
|Go one step back when retrieving values for inputs
in NIV |
|Go n steps back when retrieving values for inputs
in NIV |
| |||||NIV relOp NIV||Relational operator |
|Logical not |
| |||||NIV |
|Logical and |
| |||||NIV |
| |||||NIV arithOp NIV||Arithmetic operation |
| |||||function |
|Function call |
| |||||NIV |
|Access field of record |
|If then else |
function||:||abs | fabs||Absolute value |
| |||||sin | cos | tan
| asin | acos | atan | atan2
| sinh | cosh||Trigonometric functions |
| |||||floor | ceil||Rounding functions |
| |||||hypot(a,b)||Calculate length of hypotenuse c, if a and b are lengths
of non-hypotenuse sides of right triangle. |
| |||||ln | log | log10 | pow | exp||Log and exponent functions |
| |||||rem | sgn | sqrt|| |
NIVL||:||list of NIV delimited by |
| rowL||:||list of NIVL delimited by |
| fieldL||:||list of field delimited by |
|Figure 8.7: The grammar of next input value expressions.|
8.4.2 Test Input Mode
Simulation inputs may also be drawn from tests in a Reactis test
suite. Such tests may be generated automatically by Reactis
Tester, constructed manually in Reactis Simulator, or
imported using a comma separated value file format. By convention
files storing Reactis test suites have names suffixed by .rst.
A Reactis test suite may be loaded into Simulator by clicking
in the toolbar to the right of Source-of-Inputs Dialog (window
item 18 in Figure 8.1) or by selecting the
Test Suite -> Open menu item.
When a test suite is loaded, the name of the test suite
appears in the Reactis for C title bar and the tests of the suite
are listed in the Source-of-Inputs Dialog.
When executing in test input mode while Test Suite -> Compare
Outputs is selected, after each simulation step, Simulator
compares the values computed by the code against the values stored in
the test suite for those items. Any difference is flagged if it
exceeds the tolerance
that output. See Section 6.5 for more information on specifying
tolerances for outputs.
8.5 Tracking Data-Item Values
Reactis Simulator includes several facilities for interactively
displaying the values that data items assume during simulation. The
watched-variable list, or “watch list” for short, displays
the current values of data items designated by the user as “watched
variables.” You may also attach scopes to global or static
local variables in order to display their values at the end of a
simulation step plotted on a graph with time on the horizontal
axis. Scopes let you easily see how a variable changes during a
simulation run. Distribution scopes enable you to view the set
of values a data item has assumed during simulation (but not the time
at which they occur).
Difference scopesmay be opened for
harness outputs when reading inputs from a test in order to plot
the values computed by the program under test against the values stored in the test
for the output.
You may add data items to the watch list, or attach scopes to them, by
right-clicking on a data item in the Reactis main panel and
selecting an entry from the resulting menu as described in
You may save the current configuration of the data tracking facilities
(the variables in the watch list and currently open scopes along with
their locations) for use in a future Simulator session. You do
so, by selecting View -> Save Profile As... and using the
resulting file selection dialog to specify a file in which to save a
Reactis profile (.rsp file ). The profile may be loaded at
a future time by selecting View -> Load Profile....
8.5.1 The Watched-Variable List
The watch list is displayed in a panel at the bottom of the
Simulator screen as shown in Figure 3.12. By
default this panel is hidden, although adding a variable to the watch
list causes the panel to become visible. Visibility of the panel may
also be toggled using the View menu as described in
Section 8.2. The panel displays a list of
data items and their values. The values are updated when Simulator
The contents of the watch list may be edited using a pop-up menu that
is activated from inside the watch-list panel. Individual data items
in the panel may be selected by left-clicking on them. Once an item
is selected, right-clicking invokes a pop-up menu that enables the
selected item(s) to be deleted, have a scope opened, or have a
distribution scope opened. If no item is selected, then these
choices are grayed out. The right-click pop-up menu also includes
an entry Add Variables which displays a list of all data
items in the program under test which may be added to the watch list.
The View menu contains operations for displaying / hiding the
watch list, adding data items to the watch list, clearing the watch
Scopes appear in separate windows, an example of which may be found in
Figure 8.8. The toolbar of each scope window contains
nine or more items.
|Figure 8.8: A scope window plotting desired speed (green) and
actual speed (yellow).|
Labeled Window Items
- Reset the zoom level of the scope to fit the whole plot (see more on
- Plot signal as solid lines.
- Plot signal as points.
- If a scope displays multiple signals, this button toggles whether
or not all signals share the same y-axis or each is plotted on its own
- Save the current scope configuration as a
signal group. A signal group is a set of signals along with
the settings for displaying the signals in a scope. After saving
a signal group, you can reopen a scope for the group in future Reactis
sessions. You can add additional signals to a signal group by
right-clicking on a signal in the main Reactis panel (when Simulator
is enabled), selecting Add to Scope, and selecting the
signal group to be extended. To reorder the signals in a group or
remove a signal, open a scope for the signal group then click the
Settings button (item 8).
- Export scope data as either text (csv) or graphics (png, gif, bmp, tif or jpg).
- Copy a screen shot of the scope to the clipboard.
Configure the scope settings, including reordering the signals or deleting a signal.
- Display help for scopes.
- Toggle display of signal 1.
- Toggle display of signal 2.
To zoom in to a region of interest of the signal shown in the scope,
left-click the top-left corner of the region, hold the button and
drag to the lower right corner of the region. The scope will zoom
in to the selected region. To zoom out, either click the zoom-to-fit
button in the toolbar or right-click in the scope window. Right-clicking
will return to the zoom level that was active before the last zoom.
When zoomed in, it is possible to move the displayed region within the
scope window. To move the region, hold down the CTRL key and click-and-drag
with the left mouse button.
If more than one data item is plotted on a scope, then a toggle button will
appear in the toolbar for each data item (window items 10 and
11 in Figure 8.8). Turning one of these buttons
off will hide the corresponding data item in the scope. Hovering over the
button will display the data item to which the button corresponds.
8.5.3 Distribution Scopes
Distribution scopes also appear in separate windows, an example of
which may be found in Figure 8.9. The values
a data item assumes are displayed as data points distributed across
the X-axis. Zooming in distribution scopes works the same as in
|Figure 8.9: Distribution
scopes plot the values a data item has assumed during simulation.|
8.5.4 Difference Scopes
When executing tests from a test suite, a difference scope may be opened by
right-clicking on a test harness output and selecting Open Difference
Scope. The resulting scope plots the expected
value (from the test) against the actual value (computed by the program under test),
as shown in Figure 8.10.
If the difference between the two values
exceeds the tolerance specified for the output (see
Section 6.4.1), then a red background in the difference
scope and a red bar on the X-axis highlight the difference.
After zooming into an area of difference, white and yellow and green background
regions around the plotted values highlight the tolerance, as shown in
Figure 8.11. The green region represents the overlap
between the tolerance of the test and model values. A difference is flagged
whenever the test or model value lie outside of the green region.
|Figure 8.10: A difference scope may be opened by right-clicking
on a test harness output and selecting Open Difference Scope. The scope plots
the values stored in a test for an output and the values computed by the program
for the output. Differences are flagged in red.|
|Figure 8.11: The white and yellow colored backgrounds around the
value lines highlight the tolerance intervals of the test and model values.
The overlap between the yellow and white regions is colored green. If either the
test or program value lie outside the green region, a difference is flagged.|
8.6 Tracking Code Coverage
Chapter 7 describes the coverage metrics that
Reactis for C employs for measuring how many of a given class of
syntactic constructs or coverage targets that appear in the code
have been executed at least once. Simulator includes extensive
support for viewing this coverage information about the parts of the
code that have been exercised by the current simulation run. If a
test suite is being executed the coverage data is cumulative. That is
all targets covered by the portion of the current test executed so
far, plus those targets exercised in previous tests are listed as
8.6.1 The Coverage Summary Dialog
The Coverage Summary Dialog shown in Figure 8.12
may be invoked at any time Simulator is enabled by selecting
Coverage -> Show Summary. The dialog reports summary
statistics for each coverage criterion tracked by Reactis.
Each row in the dialog corresponds to one of the criterion
and includes five columns described below from left to right.
The name of the coverage criterion reported in the row.
- The number of targets in the criterion that have been exercised
at least once.
- The number of targets in the criterion that are unreachable.
A conservative analysis is performed to check for unreachable
targets. Any target listed as unreachable is provably unreachable;
however, some unreachable targets might not be flagged as unreachable.
- The number of reachable targets in the criterion that have not been exercised.
- The percentage of reachable targets in the criterion that have been exercised
at least once.
|Figure 8.12: The Coverage Summary Dialog|
8.6.2 Coverage Information in the Main Panel
Selecting Coverage -> Show Details toggles the highlighting of
uncovered targets in the main panel. Targets that have been covered
are drawn in black, while red implies an uncovered target. Please
refer to Chapter 7 for a detailed description of
how the different coverage metrics are highlighted in the main panel.
Hovering over an exercised target will cause a pop-up to be displayed
that gives the test and step in which the target was first executed.
This type of test and step coverage information is displayed with a
message of the form
test/step. A “.” appearing in the test
./step denotes the current simulation run which has
not yet been added to a test suite.
|Figure 8.13: Viewing coverage details for a decision.|
For items included in the decision, condition, MC/DC, and MCC metrics,
detailed coverage information may be obtained by right-clicking on the item
and selecting View Coverage Details. A dialog similar to the one shown in
Figure 8.13 will appear with coverage information. This
dialog has two tabs, one titled Decision which contains
Decision, Condition, and MC/DC details,
and a second named MCC which contains MCC details.
Item 1 in Figure 8.13 shows the coverage details dialog
with the Decision tab selected. The table within this tab
describes the coverage status of all decision, condition,
and MC/DC targets for the following decision:
g_dsMode==M_INIT && (set && !deactivate)
This decision contains three conditions:
Conditions are the atomic Boolean expressions that are used in
(for more details on decisions and conditions, see
Sections 7.4 and 7.5).
Each decision details table contains seven columns,
numbered 1-7 in Figure 8.13.
These are interpreted as follows:
The test/step during which the decision first evaluated to true.
- The test/step during which the decision first evaluated to false.
- The conditions from which the decision is composed.
- The test/step during which the condition first evaluated to true.
- The test/step during which the condition first evaluated to false.
- The condition values and test/step during which an MC/DC target was covered
and the decision evaluated to true.
- The condition values and test/step during which an MC/DC target was covered
and the decision evaluated to false.
Note that although all targets were covered in Figure 8.13,
this will not necessarily be the every time you view the details of a
decision, in which case a test/step value of
-/- will indicate
that a target has not yet been covered.
MC/DC requires that each condition independently affect the
outcome of the decision in which it resides.
(See Section 7.6 for additional details.)
When a condition has
met the MC/DC criterion in a set of tests, columns 6 and 7
of the table explain how. Each element of these two columns
has the form bbb:test/step, where each b reports the
outcome of evaluating one of the conditions in the decision during the
test and step specified. Each b is either
T to indicate
the condition evaluated to true,
F to indicate the condition
evaluated to false, or
x to mean the condition was not
evaluated due to short circuiting.
|Figure 8.14: Viewing MCC details for a decision.|
In addition the to MC/DC, Reactis can also measure
Modified Condition Coverage, or MCC.MCC targets every possible combination of conditions
within a decision, so that a decision containing N conditions
can result in as many as 2N MCC targets, although the actual number may be less
if short-circuited evaluation is used.
Figure 8.14 shows the coverage details dialog
with the MCC tab selected.
Each row of this table corresponds to a single MCC target.
The table columns are interpreted as follows:
Each of these columns corresponds to a condition.
Every condition within the decision is always represented by a single column
in the table.
target, all conditions have one of three possible values:
- The condition is true.
- The condition is false.
- The condition is not evaluated due to short-circuiting.
- The next-to-last column contains the decision outcomes for each MCC target.
- The last column gives the test/step in which the MCC target was covered.
|Figure 8.15: Filtering MCC coverage information.|
MCC coverage details can be
filtered by clicking on the column headers,
as shown in Figure 8.15.
A filtered column header is indicated
by a prefix of T:, F:, or x:, which correspond to
the column values True, False, and x, respectively.
In Figure 8.15, items 1 and 2 refer to columns with active filters:
Only MCC targets for which the condition
g_dsMode==M_INIT evaluated to true are
being shown, as indicated by the T: prefix in the header for this column.
- Only MCC targets for which the decision evaluated to false are
being shown, as indicated by the F: prefix in the header for this column.
Clicking on a column header advances the filter setting for that column
to the next feasible value, eventually cycling back to unfiltered.
All columns can also be reset to the unfiltered state at any time
by clicking on the Clear Filter button (item 3 in Figure 8.15).
Note that the individual filters for each column are combined exclusively
(i.e., using the Boolean and operator),
so that only targets which satisfy all active filters
8.6.3 The Coverage Report Browser
The Coverage-Report Browser enables you to view detailed coverage
information and export the reports in HTML format. It is invoked
by selecting Coverage -> Show Report and is described in
detail in Chapter 12.
8.7 Exporting and Importing Test Suites
8.7.1 Exporting Test Suites
|Figure 8.16: The Reactis test-suite export window.|
The export feature of Reactis for C allows you to save .rst files in different
formats so that they may be processed easily by other tools. The feature is
launched by selecting Test Suite -> Export... when a test suite is loaded
in Simulator. You specify the format and name of the exported file in the
General tab of the Export Dialog (Figure 8.16).
For some export formats, other tabs appear in the dialog to enable you to
fine-tune exactly what is included in the exported file. In the case of .csv files,
you may specify a subset of tests from the test suite to be exported as well as
which data items (inputs, outputs, configuration variables) should
be included in each test step. The following formats are currently supported:
- .csv files:
Suites may be saved as comma separated value (CSV) files.
The different tabs of the export dialog enable you to
specify which data from a test suite should be exported. Namely,
you can indicate which tests should be exported and for each test
step which inputs, outputs, and configuration variables
should have values recorded.
If the Compress output check box is selected, then test steps
will be omitted if no item that would be recorded in the step is
different from the corresponding value in the previously recorded step.
This is especially useful when exporting only input data for
a test in which inputs are held constant for a number of steps.
The first line of an exported file will contain a comma separated
list of the names of the harness inputs, outputs, and configuration
variables that were selected for export. A column recording the
simulation time has the label
___t___. Any names containing
non-alphanumeric characters will be surrounded by double quotes
") and newlines in names will be translated to
After the first line, subsequent lines contain either:
- A comma-separated list of values that includes one value for
each item appearing in the first row. The order of the values in a
row corresponds to the order the items appeared in the first line.
Each such line contains the values for one simulation step. For
array valued items, the elements of the array
appear within double quotes (
") as a comma-separated
- An empty line signaling the end of a test.
- .txt files:
- Suites may be saved in a more verbose plain ASCII
format to facilitate inspection of the test data.
8.7.2 Importing Test Suites
Reactis can also import tests and add them to the current test suite.
Test suites may be imported if they are stored in the Reactis’s native
.rst file format or in the comma separated value (CSV) format
(described above) that Reactis exports. The import feature is
launched by selecting Test Suite -> Import... when Simulator
To execute a test suite in Simulator, the test suite must match the currently selected harness. A test suite matches a
harness if it contains data for the same set of inputs, outputs, and
configuration variables as the harness. If an externally visible data
item (input, output, or configuration variable) is added to or removed
from the harness, then previously constructed test suites will no longer
match the new version of the harness. The import facility gives you a
way to transform the old test suite so that it matches the new version
of the harness. Such remapping is also available when importing
The Import Dialog, shown in Figure 8.17, is used
to specify how test data should be remapped during import. The dialog
contains a tab for each type of data item stored in a test suite
(inputs, outputs, configuration variables). In the case of
.csv files, the import dialog also contains a tab Not
Imported that lists items present in the CSV file that are not
scheduled to be imported. When an .rst file includes an item not
scheduled to be imported, it is placed at the bottom of the
appropriate tab. For example, if a test suite contains an input
variable X and is being imported with respect to a harness that has
no input variable X, then X will appear at the bottom of the
Input variables tab and be highlighted in yellow.
Each data item tab (e.g. Inputs) includes a column (e.g.
Harness Input Name) listing the code elements in that category. The
Suite column lists items from the file being imported that map to the
corresponding harness item. In most cases a data item X in the test suite being
imported will map to an item with the same name in the harness. If the harness
contains an item not found in the test suite being imported, then the corresponding
Suite column entry will be listed as Random Value and be
highlighted in yellow (as shown in Figure 8.17 for input brake).
If this setting is not changed, then upon import a random value will be
generated for the input at each test step. The value to be mapped to any
harness item may be changed by double clicking on the corresponding entry in the
Suite column (alternatively selecting the item and clicking the
button Select Suite Item) and then using the resulting dialog to
either select an item from the test suite being imported or set it to
|Figure 8.17: The Import Dialog allows you to import external
test data (comma separated value format) and if necessary transform the data
to produce a test suite that matches a harness. The import facility is also
used to transform an .rst file to make it match a program under test.|
8.8 Updating Test Suites
Test Suite -> Update... creates a new test suite that retains
the inputs from the current test suite, but updates the outputs
with values computed by the execution of your code on the existing
inputs. This provides a means to reuse previously constructed
test suites when your code changes in a way that causes its
externally visible behavior to change.