Progress in cancellable multi-threaded control software

K. Shortridge; T. J. Farrell

doi:10.1117/12.856217

Translator Disclaimer

19 July 2010 Progress in cancellable multi-threaded control software

K. Shortridge, T. J. Farrell

Author Affiliations +

Proceedings Volume 7740, Software and Cyberinfrastructure for Astronomy; 774029 (2010) https://doi.org/10.1117/12.856217
Event: SPIE Astronomical Telescopes + Instrumentation, 2010, San Diego, California, United States

Abstract

The AAO's DRAMA data acquisition environment provides a very successful flexible model for instrument control tasks based on the concept of named 'actions'. A task can execute a number of these actions simultaneously, and - something we have found to be of paramount importance in control systems - they can be cancelled cleanly if necessary. However, this flexibility has been achieved by use of what is essentially a collaborative multi-threading system, each action running in short 'stages' in a single-threaded task. The original DRAMA design pre-dated the general availability of multi-threading systems, but until now we have been reluctant to move to a multi-threading model because of the difficulties associated with attempting to cleanly cancel a thread stuck in a blocking operation. We now believe we have an acceptable solution to this problem, and are modifying the internals of DRAMA to produce an approach - compatible with the existing system - that will allow individual actions to execute in separate threads. It will be able to carry out dialogues with hardware in a much simpler manner than has been allowed so far, and this should simplify the coding of DRAMA tasks enormously.

Citation Download Citation

K. Shortridge and T. J. Farrell "Progress in cancellable multi-threaded control software", Proc. SPIE 7740, Software and Cyberinfrastructure for Astronomy, 774029 (19 July 2010); https://doi.org/10.1117/12.856217

ACCESS THE FULL ARTICLE