hrt-hood [email protected] real-time systems lecture 4 copyright, 2002 © adam czajka
TRANSCRIPT
![Page 1: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/1.jpg)
HRT-HOOD HRT-HOOD
Real-Time SystemsReal-Time Systems
Lecture 4Lecture 4
Copyright, 2002 © Adam Czajka
![Page 2: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/2.jpg)
Copyright, 2002 © Adam Czajka
Contents
Object types
Data flow
Object attributes
Decomposition
Classes
Distributed systems
![Page 3: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/3.jpg)
Copyright, 2002 © Adam Czajka
Object types
Active (A)
Passive (Pa)
Cyclic (C)
Sporadic (S)
Protected (Pr)
Pr B u f f e r
Put
* Get
Pr B u f f e r
Put
* Get
![Page 4: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/4.jpg)
Copyright, 2002 © Adam Czajka
Object typesPassive Objects
Pa Math Sum * Mul
Passive object == Set of operationsPassive object == Set of operations
![Page 5: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/5.jpg)
Copyright, 2002 © Adam Czajka
Object typesActive Objects – operation types
A Hotel ASER PutKey HSER * GetKey LSER Reservation HSER Confirm
Asynchronous
(ASER)
Loosely
Synchronous (LSER)
Highly Synchronous
(HSER)
Functional Functional
activation activation
constraintsconstraints
![Page 6: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/6.jpg)
Copyright, 2002 © Adam Czajka
Object typesActive Objects –
timeout constraints
Timeout constraints are related only to :
• HSER TOER_HSERTOER_HSER
• LSER TOER_LSERTOER_LSER
(Timed Operation Execution Request)
![Page 7: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/7.jpg)
Copyright, 2002 © Adam Czajka
Object typesActive Objects –
timeout constraints
A Post_Office LSER Send_Letter TOER_HSER * Telephone_Call
![Page 8: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/8.jpg)
Copyright, 2002 © Adam Czajka
Object typesCyclic Objects
C Sensor
Object is invoked periodicallyObject is invoked periodically
![Page 9: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/9.jpg)
Copyright, 2002 © Adam Czajka
Object typesSporadic Objects
S Button
ASER Start
Start operation can be raised by interruptStart operation can be raised by interrupt
![Page 10: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/10.jpg)
Copyright, 2002 © Adam Czajka
Object typesProtected Objects –
operation types
Asynchronous
(PAER) - in
Synchronous
(PSER) – in/outs
Pr Storage
LSER Put HSER * Get
Only PSER Only PSER operations can have functional operations can have functional activation constraintsactivation constraints
![Page 11: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/11.jpg)
Copyright, 2002 © Adam Czajka
Data flow
InElem
PSER
PSER
A Producer A Consumer
Pr Storage
* PutElement * GetElement
OutElem
![Page 12: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/12.jpg)
Copyright, 2002 © Adam Czajka
Data flowFunction calling rules
Active (A) Any other object
Cyclic (C), Sporadic (S) Any other object
except active (the asynchronous active
operations are allowed to be called)
Protected (Pr) Only Protected or Passive (the
asynchronous operations of all other objects are
allowed)
Passive (Pa) Only Passive
![Page 13: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/13.jpg)
Copyright, 2002 © Adam Czajka
Data flowFunction calling rules
If A and B are passive (or protected) objects
and object A calls the operation from object
B, then it is NOT allowedit is NOT allowed to call any operation
from object A by object B.
General rule :
![Page 14: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/14.jpg)
Copyright, 2002 © Adam Czajka
Exceptions
Pr Dispatcher
Schedule
In_El
Out_El
NoSpace
Pa Queue
PutElem GetElem
![Page 15: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/15.jpg)
Copyright, 2002 © Adam Czajka
Object attributes
DEADLINE
THREAD BUDGET
THREAD WCET
OFFSET
PRIORITY
IMPORTANCE
INTEGRITY
PERIOD (Cyclic objects only)
Minimum Arrival Time (Sporadic objects only)
![Page 16: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/16.jpg)
Copyright, 2002 © Adam Czajka
Object attributes
OPERATION BUDGET
OPERATION WCET
(WCET = BUDGET + ERROR_HANDLING)
CEILING PRIORITY
INTEGRITY
Operation attributes :
Protected object attributes : Goal : Goal :
To check the system To check the system
schedulability.schedulability.
![Page 17: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/17.jpg)
Copyright, 2002 © Adam Czajka
Decomposition
Objects
Operations
Whole systemWhole system
(1 active object)(1 active object)
More detailed More detailed
componentscomponents
decompositiondecomposition
Decomposed system Decomposed system
(no active objects)(no active objects)
![Page 18: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/18.jpg)
Copyright, 2002 © Adam Czajka
Decomposition
Active any other object
Passive only Passive objects
Protected Passive object + 1 Protected
Sporadic Passive, Protected, Cyclic + at least
1 Sporadic
Cyclic Passive, Protected, Sporadic + at least
1 Cyclic
Object decomposition rules :
![Page 19: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/19.jpg)
Copyright, 2002 © Adam Czajka
DecompositionDecomposition rules (operation
decomposition examples) :
ASER ASER
ASER PAER
LSER PSER
PSER PSER
Decomposition is valid only if it doesn’t affect Decomposition is valid only if it doesn’t affect
the parent object properties.the parent object properties.
![Page 20: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/20.jpg)
Copyright, 2002 © Adam Czajka
Decomposition
A Console
Display_Line
Read_Line
ASER
HSER
Decomposition example
![Page 21: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/21.jpg)
Copyright, 2002 © Adam Czajka
Decomposition
![Page 22: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/22.jpg)
Copyright, 2002 © Adam Czajka
Environmental objects
![Page 23: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/23.jpg)
Copyright, 2002 © Adam Czajka
Classes
![Page 24: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/24.jpg)
Copyright, 2002 © Adam Czajka
Distributed systems
Buffer :Buffer :
•Real objectReal object
•Client „stub”Client „stub”
•Server „stub”Server „stub”
![Page 25: HRT-HOOD Adam.Czajka@cs.put.poznan.pl Real-Time Systems Lecture 4 Copyright, 2002 © Adam Czajka](https://reader035.vdocuments.mx/reader035/viewer/2022062801/56649e4d5503460f94b4398d/html5/thumbnails/25.jpg)
Copyright, 2002 © Adam Czajka
SummarySummary
Object types
Data flow
Object attributes
Decomposition
Classes
Distributed systems