Inside Macintosh: Open Transport /

Chapter 7 - Process Management / Process Management Reference

Functions / Working With Deferred Tasks

OTScheduleDeferredTask

Schedules a task for execution at deferred task time.

C INTERFACE

Boolean OTScheduleDeferredTask(long dtCookie)

C++ INTERFACES

None. C++ applications use the C interface to this function.

PARAMETERS

dtCookie

A reference that identifies the task to be scheduled.

DESCRIPTION

The OTScheduleDeferredTask function schedules for execution at the next deferred task time the task associated with the dtCookie parameter, which is the reference returned by the OTCreateDeferredTask function.

You can call this function at any time. If you have not yet destroyed a task, you can use this function to reschedule the same task more than once.

If you makes multiple calls to the OTScheduleDeferredTask function before the task is executed, additional tasks are not scheduled; only one instance of each unique task can only be scheduled at a time.

This function returns true if it scheduled the deferred task successfully, false if not. If it returns false and the dtCookie parameter has a valid value (other than 0), then the task is already scheduled to run. If dtCookie is invalid (a value of 0), the function returns false and does nothing.

If you want to call Open Transport from an interrupt, you can use this function (and the OTCreateDeferredTask function) instead of the standard Deferred Task Manager function DTInstall to create a deferred task that permits you to call Open Transport function calls. This allows Open Transport to adapt to changes in the underlying operating system without affecting the client's code.

SPECIAL CONSIDERATIONS

You can call this Open Transport function at interrupt time, but you must precede it by calling the OTEnterInterrupt function and you must follow it by calling the OTLeaveInterrupt function.

SEE ALSO

To create a deferred task for execution at deferred task time, call the OTCreateDeferredTask function (page 7-14).

To destroy a task created with the OTCreateDeferredTask function, call the OTDestroyDeferredTask function (page 7-18).

Before making this call from within an interrupt, use the OTEnterInterrupt function (page 7-19).

After you have made this call from within an an interrupt, use the OTLeaveInterrupt function (page 7-20).