Creating an AST
From InterBase
Go Up to Continuous Processing with isc_que_events()
The event function, event_function(), should be written to take three arguments:
- The
event_function_argspecified in the call toisc_que_events(). This is usually a pointer to the event parameter buffer that should be filled in with updated event counts. - The length of the following
events_listbuffer. - A pointer to the
events_listbuffer, a temporary event parameter buffer just like that passed toisc_que_events(), except for having updated event counts.
A result buffer is not automatically updated by the event occurrence; it is up to the event_function to copy the temporary events_list buffer to the more permanent buffer that the application utilizes.
event_function also needs to let the application know that it has been called, for example, by setting a global flag.
A sample event_function appears in the following example:
isc_callback event_function (char *result, short length, char *updated)
{
/* Set the global event flag. */
event_flag++
/* Copy the temporary updated buffer to the result buffer. */
while (length--)
*result++ = *updated++;
return(0);
};