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| Rev | Author | Line No. | Line |
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| 1085 | pj | 1 | ---------------------------------- |
| 2 | Jumping Balls demo |
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| 3 | |||
| 4 | by |
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| 5 | |||
| 6 | Paolo Gai 1999-2001 - pj@sssup.it |
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| 7 | |||
| 8 | ---------------------------------- |
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| 9 | |||
| 10 | This demo was created to show some S.Ha.R.K. functionalities in the course |
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| 11 | of Informatica Industriale , University of Pavia, Italy. |
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| 12 | |||
| 13 | The demo is composed by an application (derived by the template application |
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| 14 | distributed on the web site) and two init files. |
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| 15 | |||
| 16 | The demo is composed by: |
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| 17 | |||
| 18 | MAKEFILE The makefile used to compile the application; |
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| 19 | demo is the rule to compile the application with a CBS scheduler |
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| 20 | demo2 is the rule to compile the application with a RR scheduler |
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| 21 | README.TXT This file |
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| 22 | DEMO.H Some constants used into the demo |
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| 23 | INITFIL1.C The CBS initfile |
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| 24 | INITFIL2.C The EDF initfile |
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| 25 | INITFILE.C A makefile that cover either EDF+CBS and RR |
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| 26 | BALL.C The Jumping balls part of the demo |
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| 27 | DEMO.C The main() function and some other utility function |
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| 28 | JETCTRL.C The JET part of the demo |
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| 29 | |||
| 30 | |||
| 31 | The demo works as follows: |
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| 32 | - It works at 640x480 16 bit colors |
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| 33 | - on the left, there is the jumping ball arena, on the rigth there is the |
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| 34 | statistics about the tasks into the system. |
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| 35 | |||
| 36 | - the tasks are guaranteed using CBS and EDF. The wcet and mean execution |
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| 37 | time on my portable after a few minutes are (us): |
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| 38 | |||
| 39 | JetCtrl 7400 max 7500 CBS met |
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| 40 | JetDummy 135 max 200 CBS met |
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| 41 | JetSlide 2100 max 2100 CBS met |
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| 42 | Balls 276 max 380 EDF wcet for hard ball,100 CBS met for soft ones |
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| 43 | |||
| 44 | The system should go overloaded with 40 soft balls. |
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| 45 | |||
| 46 | - The idea is the following: |
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| 47 | - first, an edf guaranteed ball is created. |
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| 48 | - then, create a set of soft ball using space. since their met is < than the |
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| 49 | real met, they posticipate the deadlines. |
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| 50 | - if they are killed, they remain for some seconds in the zombie state |
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| 51 | - if a set of soft ball arde created (i.e., 10), and after a while all the |
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| 52 | others are created, the bandwidth is fully used, and the task posticipate |
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| 53 | their deadlines. the first set of tasks stops jumping when the bandwidth |
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| 54 | is full utilized by the newest balls until all the tasks have similar |
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| 55 | deadlines. |
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| 56 | - Note on the left the slides that represents the relative ratio |
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| 57 | between the tasks. |
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| 58 | - Note that in overload conditions the EDF task is still guaranteed |
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| 59 | - Note that PI is used with EDF, also if no theory says that it is good: |
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| 60 | - S.Ha.R.K. allows that, it is the user that have to choose if that is |
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| 61 | a non-sense |
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| 62 | - PI is independent from the implemnentation of the scheduling modules |
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| 63 | - if the second init file is used, RR is used instead of EDF+CBS. |
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| 64 | - In overload condition RR perform differently from EDF+CBS, giving to |
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| 65 | each task an equal fraction of bandwidth |
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| 66 | |||
| 67 | - note also: |
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| 68 | - the redefinition of the standard exception handler |
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| 69 | - the redefinition of the keys and the initialization of the keyboard |
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| 70 | - the myend exit function |
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| 71 | - the main() that terminates |
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| 72 | - the two parts (ball and jet) can be excluded using a #define |
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| 73 | |||
| 74 | If You have any question, please contact the author... |
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| 75 |