The Esterel v5 21 System Manual - Courses

3.4. THE REACTION INTERFACE 41
can be implemented by
void STORE_CHAR (s, i, c)
char *s;
int i;
CHAR c;
{
s[i] = c;
}
where CHAR is a user type implemented by char. The declaration “char *s”
is used instead of “string *s” as would be the case for user types.
3.4 The Reaction Interface
The reaction function provided by the Esterel compiler for a program PROG
is also called PROG. In addition, for input and output, the generated code
provides a function for each input signal, and the user must provide an
output function per output signal and a sensor function per sensor.
3.4.1 Input Signals
For each input signal IS, the Esterel compiler generates an input C function
called PROG I IS, which takes an argument of the appropriate type if the
signal IS conveys a value. For example, from the Esterel declarations
input WATCH_MODE_COMMAND;
input WATCH_TIME (WATCH_TIME_TYPE);
return R;
appearing in a module named DISPLAY, the compiler generates the following
functions:
void DISPLAY_I_WATCH_MODE_COMMAND () {...}
void DISPLAY_I_WATCH_TIME (__V) WATCH_TIME_TYPE __V; {...}
void DISPLAY_I_R () {...}
When a program PROG should react to an input event composed of one or
more simultaneous input signals, the associated input C function(s) should
be called before calling the main execution function PROG.
If several input functions are called before calling PROG, the corresponding
input signals are considered as forming the current input event of the
reaction. The input signals are considered as being simultaneous. Therefore,
the notion of “simultaneous signals” is a purely logical one at the C