Specifying a task
 
A primitive task
A composite task
An end task
An inactive task
 
Declaring parameters
 
Creating an input or input-output parameter
Creating an output parameter
 
Declaring a module

Specifying a sequence

Specifying a sum

Specifying a choice

Specifying a product

Some specifications examples
 
Generating the data flow
 
 

Definition : A task is a formal or abstract definition of a process

A primitive task

To create a task in the working zone, click in the tool bar on  And then click in the working zone where you want to create the task.

In the working zone, the task is shown as 

To update its properties to light : double-clic on the task with the left button or choose Properties in the Right Button menu. The following dialog box appears :

• The Primitive button is activated, it is a primitive task.
• Name : Task name, Execution Site : Task execution site.
• Input Params, Input Output Params and Output Params : After clicking on one of this buttons, the dialog-box permiting parameters input appears. For more informations, see the Parameters input section.
• Function : Task executed function.

A composite task

The creation method is the same as previously.

A s\Conposite task is represented in the working zone by trhis symbol : 

To update its properties : double-clic on the task with the left button or choose Properties in the Right Button menu. The following dialog box appears :

• The Composite button is activated, it is a composite task.
• The Task without delay option is inactive : no delay apply at this task.
• Name : Task name, Execution Site : Task execution task
• Input Params, Input Output Params and Output Params : After clicking on one of these buttons, the dialog-box permiting parameters input appears. For more informations, see the Parameters input section.
• Function is inactive : A composite task doesn't execute any function. It is define by a tasks aggregate. This is the reason why these fields appears greyed out.

An end task

Click on  and in the working zone appear : 
This task has no properties.
 

An inactive task

Click on  and in the working zone appear : 

This task has no properties.
 

After clicking on the "Input Params", "Input Output Params" or "Output Params" button in the task properties window, the following window appears :
 

The "New" button permits to create a new parameter.  The "Alter" button permits to modify a parameter.  The "Remove" button permits to remove a parameter.

 
 

Creating an input or input output parameter

"Type" permits to choose the parameter type. Available types are : integer double float int vector double vector float vector int matrix double matrix float matrix user type "Name" is the parameter name, it must be single in the task parameters list.  "Task" is the task name from where the parameter comes  "Source" permits to define the parameter origin :  User : it's the user who give a value to the parameter by pressing the "init"button. Task : is the task from which the parameter come Standard Input : the parameter is initialised by an unknown task.

Creating an output parameter

"Type" permits to choose the parameter type. "Name" is the parameter name, he must be single in the task parameters list. "Destination" permits to define the parameter destination : File : the parameter value is stocked in a file which name and site must be respectively entered in File and Site fields. TaskOutput : the value is kept in memory during the CAST whole execution.  "Width" is a vector dimension or a matrix number of columns.  "Height" is the matrix number of raws if the parameter is a matrix.A dimension can be define numericly or with a task parameter.

After clicking on the "Module Definition" button in the task properties window, the following window appears :
 
 

"Executable name" is the name of the executable. "Executable path" is the full path to access the above given executable. "Input Files", "Input Output Files" and "Output Files" are parameters files descriptions respectively input and output. Such files creation is describe below.

After clicking on "Input Files", "Input Output Files" or "Output Files", the following window appears :
 
 

"New" permits to create a new parameters file description "Alter" permits to modify it. "Remove" permits to erase a parameters files description.

 

After clicking on the "New" or "Alter" button, the following window appears :
 
 

"File Name" is the parameters file name, it must be single for each task. On the left, there is the parameters list, "Parameters", still available , and on the right the file composition , "Parameter File". The "Add" button permits to add a parameter to the file, you just have to select it in the left list and click on the "Add" button. The "Remove" button permits to erase the selected parameter of the file. This one will be available again. The "Replace" button permits to replace the selected parameter in the file by the one selected in the parameters list. The "Clean" button permits to clear out the parameters file., its action is like "Remove", except it acts on the whole list.

 

The sequence is an operator, its semantic is the following :

Let t1and t2 be 2 tasks, t1 sequence t2 means that the t2 task begins when t1 ends.

In the tool bar : 

In the working area : (Task_1 sequence Task_2 sequence 1 ) 

Sequence creation protocol :

• Start to create 2 primitives or composites tasks.
• Then, select in the panel the sequence operator.
• Click with the left button on the first task (in our example Task_1).
• Maintain the button pressed and move the mouse untill the second task ( in our example Task_2 ).
• Release the button, the sequence has been created.

The sum is an operator, its semantic is the following :

Let t1and t2 be 2 tasks, t1 sum t2 means that t1 or t2 task is executing.

In the tool bar by clicking on :  we have in the working zone : : (Task_2 sum Task_3) 

Sum creation protocol :

• Select the sum operator.
• Click in the working zone.
• The choice has been created.
• 2 tasks are automatically created.They are located one below the other.
• These tasks must be used as normal tasks (double click with the middle or left button to access subtasks or properties ).

• Input the sum type, determinist or indeterminist.
• for a determinist one , input the executed task and the condition if that condition is checked. The condition is composed of the testing parameter name, of the comparaison operator and of the testing value.
• Press the Apply button.
• The sum has been created.

The choice is an operator, it is identical with the sum but its representation change, its semantic is the following :

Let t1, t2 and t3 be 3 tasks, t2 choice t3 means that the t2 or t3 task is executed after the t1 task.

In the working area : (Task_2 choice Task_3)

Choice creation protocol :

• Start to create 3 tasks, primitive or composite,
• Then, specify a sequence between the first and the second task,
• and another one between the the first and the third task.
• Properties window appears :

• Input the choice type, determinist or indeterminist.
• for a determinist one, input the executed task and the condition if that condition is checked. The condition is composed of the testing parameter name, of the comparaison operator and of the testing value.
• Press the Apply button.
• The choice has been created.

The product is an operator, its semantic is the following :

Let t1 and t2 be 2 tasks, t1 product t2 means that t1 and t2 tasks are executed in parallel.

In the tool bar, click on :  and we have in the working zone (Task_1 product Task_2 ) : 

Product creation protocol :

• Select the product operator.
• Click in the working area.
• The product has been created.
• 2 tasks are automatically created. They are located one below the other.
• These tasks must be used as normal tasks (double click with the middle or left button to access subtasks or properties ).

Ou 

---

Some specification exemples

Generating the data flow graph

Task1
Task2
.......
Taskn
TypeParam1 Task1 Param1 Task2 Param11
TypeParam2 Task1 Param2 Task2 Param22
..............
TypeParamn Task1 Paramn Task2 Paramnn
..............
TypeParamm Taskn Paramm Taskp Paramqq
 

Where Task1, Task2 and Taskn are task's names from or to which parameters Param1, Param2, Paramn and Paramm of  type TypeParam1, TypeParam2, TypeParamn and TypeParamm  respectivly are output, and Param11, Param22, Paramnn and Paramqq of  type TypeParam1, TypeParam2, TypeParamn and TypeParamm  respectivly are input.
Therefore Param1 of type TypeParam1 is output from Task1 and input as Param11 to Task2, with the same data type.
 

Example

For Task1, these parameters were defined :

:  and 

In Task2, these parameters were defined :

and 

So we have :
 
    From Task1 to Task2 : Task1Param1 and Task1Param2
    From Task2 to Task1 : Task2Param3

The generated Data flow Ascii file is :

Task1
Task2
Integer Task1 Task1Param1 Task2 Task2Param1
Integer Task1 Task1Param2 Task2 Task2Param2
Integer Task2 Task2Param3 Task1 Task1Param3

Last update by Jérôme BLACHON, January 1999.

© 1997-1999 INRIA Rhône-Alpes