Hierarchy of Software Complexity Application Programs Sequential - - PDF document

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1 Sequential Programming Concurrent Programming Distributed Programming Real-Time Programming Security Programming Reliable (FT) Programming Quality of Service Tradeoffs: accuracy, real-time, security, reliability, device constraints Embedded Programming

Hierarchy of Software Complexity

Middleware Application Programs

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Autopilot Example

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Software Modules Structure

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Timing

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System All Periodic Periodic/Sporadic All Sporadic Periodicity

Distributed Scheduling Problem Space Taxonomy

Remote Calls Local Only E2E-N E2E-1

(per request)

System Conditions Static Dynamic Constraints All Hard All Soft Hard/Soft

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Priority Driven Example

J1, 3 J2, 1 J3, 2 J4, 2 J5, 2 J6, 4 J7, 4 J8, 1

Precedence Graph

Subscript indicates priority Number next to job indicates exec time J5 released at time 4, all others at time 0 Jobs to be scheduled on two processors: P1 and P2

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Priority Driven Example

2 4 8 10 12 6 2 4 8 10 12 6 preemptive non-preemptive J1 J4 J7 J6 J2 J3 J7 J5 J8 J1 J4 J5 J6 J2 J3 J7 J8 P1 P2 P1 P2

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EDF Non-optimality Example

2 4 8 10 12 6 J1 J2 J3 Missed deadline EDF Schedule 2 4 8 10 12 6 J1 J3 J2 14 Feasible Schedule

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System Local Only E2E-N Static Dynamic All Hard All Soft All Periodic Periodic/Sporadic All Sporadic Periodicity Remote Calls System Conditions Constraints

Distributed Scheduling Problem Space Taxonomy

E2E-1

(per request)

Hard/Soft

• Liu Ch 4

Liu Ch 6 Liu Ch 7 Liu Ch 9

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Scheduling Fixed Priority Reservation Adaptive? Mechanism

Distributed Scheduling Solution Space Taxonomy

Adaptive

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• Algorithms

Offline Only On/Offline Online Only Analysis

• Static

Dynamic Parameters