Software Reuse & Distributed Services
- 1. Software Reuse across multiple processor cores - Component/Services based solution - Naveen Rajanikantha
- 2. Abstract Problem: Software reuse Move blocks of software from different cores Reduced cost of development (time & effort) A Solution Software blocks as Components providing Services Services based abstraction (rather than function based) Distributed services framework – hides core details. Service only interacts with Distributed framework.
- 3. Software Services Provides well defined set of services Defines how to access services – messages Services are Cohesive and De-coupled Services rely on Component framework for every thing. All OS services - provided by Component Framework. Services Agnostic about Cores and Operating system
- 4. Distributed Services Framework (Component Framework) Provides environment where services reside Very Critical Provides OS services event de-multiplexing and event handler dispatching, signal handling, service initialization, interprocess communication, buffer management, message routing, dynamic (re)configuration of distributed services, concurrent execution and synchronization. etc Hides all details of multiple cores. Encapsulates all OS and H/W Cores. Provides OS services Abstraction Not functional based abstraction Provides Distributed patterns like Reactor, Active Object, etc… Semaphore etc.. Are hidden within patterns. This needs to be ported for new Cores, New OS and any new IPC mechanism b/w cores.
- 5. Services and Framework across 3 cores Core 1 Core 2 Core 3 Distributed Services Framework Distributed Services Framework Distributed Services Framework Service B Service C Service E Service F Service A Service D
- 6. Software Reuse How does this provide Software reuse? Services provided by framework don’t change, Just a recompile of all services. Services Framework will encapsulate/Hide all the changes in H/W and OS. Services Framework will incur cost of porting to new OS and new H/W Services are agnostic of core they are running and easily move between cores.
- 7. Ease of Development & Testing Development and Test Services. Port Services framework to Windows. Development env independent of Hardware. Build Test Services that would send service request messages to Service under test. Pure software Services can be completely tested independent of H/W Provides maximum reuse of services. Architecture is flexible to move things around. Reduced Testing and integration time
- 8. Conclusion Using Services and Distributed Services Framework. Software reuse Provides a mechanism for Host based Services/Software development & Testing Porting effort confined/encapsulated in Distributed Services framework Service/Software now agnostic of H/W Architecture is flexible to move things around. Abstractions are going to add little bit of overhead. Greater Software reuse and Reduced Testing time Main Concept: Services and Services based Abstraction
- 9. Example All Layered Stack specification, Lends itself to Services They are already defined in terms of services Services Framework Adaptive Communication Environment (ACE) although not distributed, It can be added. Many Network Elements use this type of FWK – Load Distribution. Services not tightly coupled to Cores, Services can be moved between cores.
- 10. References Adaptive Communication Environment - http://www.cs.wustl.edu/~schmidt/ACE-overview.html Pattern-Oriented Software Architecture: Patterns for Concurrent and Networked Objects Douglas C. Schmidt Symbian Documentation