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CANCEL

CANCEL is handled by calling DTASK_CANCEL().

Details of the OBEY transaction which started this action are obtained from the COMMON blocks (DTASK_CMN) then DTASK_APPLIC() is called with context CANCEL and that in turn calls the user's code. See SUN/134 for examples of how the user's code might handle a CANCEL

On return from DTASK_APPLIC the status and REQUEST returned from the application are checked (DTASK_ACT_SCHED()) to see whether the action is to be terminated or is to continue rescheduling. In any case, an acknowledgement is sent to the task which requested the CANCEL. If the action has ended, an acknowledgement is also sent to the task which issued the OBEY.



next up previous 68
Next: CONTROL Context
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ADAM The Control Subsystem
Starlink System Note 77
A.J. Chipperfield
16 August 2001
E-mail:ussc@star.rl.ac.uk

Copyright © 2000 Council for the Central Laboratory of the Research Councils