Performing Periodic Tasks
One way to install a periodic Time Manager task is to have the task reactivate itself. Because the task record is already inserted into the
To call PrimeTime, however, the task needs to know the address of the corresponding task record. In the revised and extended Time Managers, the task
record's address is placed into register A1 when the task is called. The
following program illustrates how the task can reactivate itself by retrieving
the address in register A1 and passing that address to PrimeTime. // Defining a periodic Time Manager task
// Assuming inclusion of
typedef struct { // Time Manager information record
TMTask atmTask; // original and revised TMtask record long tmRefCon; // space to pass address of A5 world
} TMInfo;
typedef TMInfo *TMInfoPtr;
pascal TMInfoPtr GetTMInfo (void)
= 0x2E89; // MOVE.L A1,(SP)
pascal void MyTask (void);
pascal void MyTask () // for revised and extended TMs
{
TMInfoPtr recPtr;
long myDelay; // delay value
recPtr = GetTMInfo(); // first get your own address
myDelay = 2000; // no. of milliseconds to delay
// do something in here
}
Note: The technique illustrated in this program cannot be used with the
original Time Manager because that version of the Time Manager does not pass the address of the task record in register A1.