©scilabs 2002 real-time corba ©scilabs ingenieros s.l. 2002 miguel segarra josé antonio clavijo...
Post on 20-Dec-2015
219 views
TRANSCRIPT
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA
©SCILabs Ingenieros S.L. 2002 www.SCILabs.es
Miguel SegarraJosé Antonio Clavijo
HRTC
Vienna Plenary Meeting
©SCILabs 2002
www.SCILabs.es
Speech Contents
• Introduction• Real-Time/Minimum CORBA
development• The DOTS Project• Conclusions
©SCILabs 2002
www.SCILabs.es
Introduction
• What is CORBA?• Useful URLs
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
What is CORBA
• It is an specification of the OMG
• CORBA specifies an architecture for building distributed object systems, common services for those systems and protocols for interoperability among CORBA implementations.
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
What is CORBA? Introduction RT CORBA Dev. DOTS Project Conclusions
HorizontalCORBA Facilities
Object Request Broker
CORBA Services
VerticalCORBA Facilities
ApplicationObjects
• The CORBA “software bus”
©SCILabs 2002
www.SCILabs.es
What is CORBA?
UMLModeling CORBAservices
CORBAfacilities
Business Object Facility
Common Business Objects
CORBADomains
CORBADomains
CORBADomains
Me
ta-O
bje
ct F
aci
lity
SE
CU
RIT
Y
IDL Interfaces, Mappings, & ORB
Realtime, Embedded options
Interoperability: IIOP, Asynch
Components, Scripting
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
What is CORBA?
• How does it work? Introduction RT CORBA Dev. DOTS Project Conclusions
•Server Side•Client Side
Object Request BrokerIDL
IDL
POA
CLIENT
SERVANT
IDL
©SCILabs 2002
www.SCILabs.es
What is CORBA?
Object Request BrokerIDL
IDL
POA
CLIENT
SERVANT
Introduction RT CORBA Dev. DOTS Project Conclusions
• How does it work?
Client.GetValue(); Servant.GetValue();
©SCILabs 2002
www.SCILabs.es
What is CORBA?
Object Request BrokerIDL
IDL
POA
CLIENT
SERVANT
Object Request BrokerIDL
IDL
POA
CLIENT
SERVANT
Introduction RT CORBA Dev. DOTS Project Conclusions
GIOP
Client.GetValue();
Servant.GetValue();
©SCILabs 2002
www.SCILabs.es
Useful URLs
• Our Home Page:– http://www.scilabs.es
• OMG Home Page:– http://www.omg.org
• OMG Specs:– http://www.omg.org/technology/
documents/spec_catalog.htm
• OMG News:– http://www.omg.org/news
• Lots of OO/CORBA URLs– http://www.cetus-links.org
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Speech Contents
• Introduction• Real-Time/Minimum CORBA
Development• The DOTS Project• Conclusions
©SCILabs 2002
www.SCILabs.es
RT/Minimum CORBA Development
• CORBA features for real-time/embedded development
• Specifications vs. Reality• RT CORBA Tools for System
Design• Some Lessons Learnt• Industry Trends
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time/Minimum CORBA Features
• Characteristics of RT CORBA systems– End-to-end system predictability
(not high performance)– Allocation of resources
• Characteristics of Minimum CORBA systems– Limited resources– Full CORBA interoperability
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time/Minimum CORBA Features
• End-to-end predictability– Respecting thread priorities
between clients and servers– Bounding the duration of thread
priority inversion– Bounding latencies of operation
invocations
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time/Minimum CORBA Features
• Management of resources– Process, storage and
communication• Threadpools• Priorities• Number of concurrent requests• Transport connections
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time/Minimum CORBA Features
• Real-Time CORBA 1.0 addresses fixed-priority real-time systems– Priority-based scheduling rather
than e.g. deadline based
• Real-Time CORBA 2.0 addresses dynamic scheduling
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time/Minimum CORBA Features
• Minimum CORBA defines a cut down profile of CORBA
• Dynamic aspects of CORBA are removed
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
RT/Minimum CORBA Development
• CORBA features for real-time/embedded development
• Specifications vs. Reality• RT CORBA Tools for System
Design• Some Lessons Learnt• Industry Trends
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA
Specifications vs. Reality
Introduction RT CORBA Dev. DOTS Project Conclusions
Messaging
CORBA
MinimumCORBA
TimeService
But close to the process resources are very limited!
©SCILabs 2002
www.SCILabs.es
Specifications vs. Reality
Introduction RT CORBA Dev. DOTS Project Conclusions
CORBA
MinimumCORBA
Real-Time CORBA
Messaging
TimeService
Dynamic part of CORBA
In embedded/real-time systems a lot of decisions are made at design time!
©SCILabs 2002
www.SCILabs.es
RT/Minimum CORBA Development
• CORBA features for real-time/embedded development
• Specifications vs. Reality• RT CORBA Tools for System
Design• Some Lessons Learnt• Industry Trends
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Stub
Client
Real-Time CORBA Tools For System Design
Introduction RT CORBA Dev. DOTS Project Conclusions
threadpriority
Provide predictability by controlling ORB behavior
ORB
connection
ORBInvoke priority
protocol
Skeleton
POA
threadpriority
concurrency
Servant
©SCILabs 2002
www.SCILabs.es
Stub
Client
Real-Time CORBA Tools For System Design
Introduction RT CORBA Dev. DOTS Project Conclusions
Impact on ORB architecture of predictability issues
ORB
buffering
ORBdelay
Skeleton
POA
threaddispatching
Servant
buffering
request dispatchingmarhalling
marhalling
Memory mgmt
Memory mgmt
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Real-time CORBA features– RT ORB and RT POA– RT CORBA priority and priority mappings– RT CORBA priority models– Priority transforms– RT CORBA mutex– Threadpools– Connection management– Protocol selection– Invocation timeout– Bounding of ORB priorities
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• RTCORBA::RTORB– It is an extension of the
CORBA::ORB with operations to create new real-time entities (e.g. threadpool, mutex and new RT policies)
• RTPortableServer::POA– Add to the PortableServer::POA
operations to set priority on an object reference basis
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
Introduction RT CORBA Dev. DOTS Project Conclusions
0
RTCORBA::Priority31
0
31
0
255
OS #1 native priority model
4
25
OS #2 native priority model
Real-Time CORBA Priority
•An OS independent priority scheme. The same range of CORBA priorities for all platforms. Custom priority mappings are allowed.
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design• Real-Time CORBA Priority
Models– Client propagated– Server declared– Per object reference basis
Introduction RT CORBA Dev. DOTS Project Conclusions
Stub
Client
ORB ORB
Skeleton
POA
Servant
What is the invocationPriority?
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Client propagated priority model
Introduction RT CORBA Dev. DOTS Project Conclusions
Stub
Client
ORB ORB
Skeleton
POA
Servant
client running at priority 100Invocation executed at priority 100
Client’s priority propagated along the path to server in a
service context
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Server declared priority model
Introduction RT CORBA Dev. DOTS Project Conclusions
Stub
Client
ORB ORB
Skeleton
POA
Servant
client running at priority 100Invocation executed at priority 3347
Client’s priority IS NOT propagated along the path to
server in a service context
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Priority transforms– Inbound– Outbound
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Real-Time CORBA mutex– An API to give access to the
mutex implementation that the ORB uses
– This gives consistency to the priority protocol used
– Basic tool for resource protection
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Threadpools– Server-side tool to handle
invocations– Provide concurrency control– Allows thread pre-creation and reuse– Setup of idle threads priority
• Two flavors of threadpools– Without lanes– With lanes
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Threadpools Introduction RT CORBA Dev. DOTS Project Conclusions
POA A POA B
ORB
threadpool
POA A POA B
ORB
Threadpool A Threadpool B
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Threadpools Introduction RT CORBA Dev. DOTS Project Conclusions
Threadpool
Threadpool
Lane A Lane B
•Without lanes- stacksize 512- prio 100- Static 5- Dynamic 3- Req buff Yes- Max Reqs 3- Req Buf Sz 5120
•With lanes- Stacksize 512- Lanes 2- Borrowing Yes- Req buff Yes- Max Reqs 3- Req Buf Sz 5120-Lane A
-Prio 1110-Static 2-Dynamic 1
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Handling connections– Implicit and explicit binding– Multiplexed connections– Private connections– Banded connections
Introduction RT CORBA Dev.DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
ORB ORB
client
client client
clientserver
Multiplexed:Resource contention by shared connection
ORB ORB
client
client client
clientserver
Private connection:Exclusive use of a connection by a client
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
ORB
Real-Time CORBA Tools For System Design
ORB
client
client client
client
server
0 - 1300
9786 - 21340
Banded connections:Invocation priority determines connection to use
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
• Protocol configuration– It can be done at the client or
server side of the ORB– Available protocols are exposed
to clients in IORs when the configuration is set from the server side
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
Introduction RT CORBA Dev. DOTS Project Conclusions
RTOS A
Client
ORB A ORB B
Skeleton
RTOS B
Servant
Stub
TCP/IPATM OtherATMTCP/IP
Object Reference
Invocation
©SCILabs 2002
www.SCILabs.es
Real-Time CORBA Tools For System Design
Introduction RT CORBA Dev. DOTS Project Conclusions
RTOS A
Client
ORB A ORB B
Skeleton
RTOS B
Servant
Stub
TCP/IPATM OtherATMTCP/IP
Invocation timeout
©SCILabs 2002
www.SCILabs.es
RT/Minimum CORBA Development
• CORBA features for real-time/embedded development
• Specifications vs. Reality• RT CORBA Tools for System
Design• Some Lessons Learnt• Industry Trends
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Some Lessons Learnt
• In general, sources of unsatisfactory results are not easy to find.
• Pattern-based development provides good results but... there is no ORB pattern.
• Improving the ORB by experimenting is of great help. Ask “Why...?”. Run lots of tests.
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Some Lessons Learnt
• Performance– Avoid new/delete. Expensive and
leads to memory fragmentation.– Avoid linear searches
• Unmarshalling IORs• DeMux to object implementation
and operation invocation.– Copying of data: From client to ORB
to network. From network to ORB to server.
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Some Lessons Learnt
• Performance.– Buffer resizing strategy.– Threads life-cycle. Keep threads
alive but idle.– Avoid overhead of first invocation.
Early binding.– Compare to raw-socket
application to find ORB overhead.– Measure ORB behavior with
varying data sizes. (must be linear)
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Some Lessons Learnt
• Predictability– Worst time case is hard to find:
several sources of non determinism (application, ORB, OS, network).
– Configure the ORB in a simpler manner to reduce the number of “changing things” (e.g. Use static buffers).
– Being predictable introduces ORB overhead (priority service contexts)
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Some Lessons Learnt
• Footprint– What is too much?– Performance vs. Footprint– Performance vs. Services
provided– Memory left on board by the ORB
for the application– Bound memory usage by the ORB– Size of the ORB library
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
RT/Minimum CORBA Development
• CORBA features for real-time/embedded development
• Specifications vs. Reality• RT CORBA Tools for System
Design• Some Lessons Learnt• Industry Trends
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Industry Trends
• The embedded industry is not used to object solutions
• Embedded systems have issues not considered in the RT CORBA specification
• There is no embedded CORBA specification
• Let the user configure default behavior of the ORB (e.g. Default multiplexing of connections)
• Preallocation and control of ORB resources
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Industry Trends
• Usage of multiple protocol stacks: adopt the OCI framework
• The ORB architecture must be open to developers: configure ORB in a “plug-in” fashion.
• Tracing execution and debugging tools
• Specialised services for real-time
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Speech Contents
• Introduction• Real-Time/Minimum CORBA
Development• The DOTS Project• Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• Overview• Participants• Objectives• Domain• Elitel-5: an embedded device• Some results
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Overview
• Overview– To establish an open software
model, built upon real-time distributed object technologies and emergent telecontrol standards to allow the optimum exploitation of the interoperation capabilities of devices and systems in the distributed context of an electric power grid.
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Participants
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Objectives
• Distributed Object Telecontrol Systems & Networks
• IST-1999-10258-DOTS• Real-Time CORBA• Minimum CORBA• IEC-61850 for control systems
in electrical substations
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Objectives
• From the IEC-61850 draft1. The functions of the substation automation system (SAS) and
their communication behaviour shall be described device independent.
2. The functions shall be described as far as necessary only to identify the information to be exchanged.
3. The free allocation of functions to devices shall be supported.4. The functions used today are well known but the standard
shall be open for future requirements.5. The interaction of device independent distributed functions
shall be described by the logical interfaces in between which may be freely allocated to physical interfaces or LANs.
6. The standard shall define generic information to be communicated and the communication behaviour of the functions to provide for planned and future functional extensions of substation automation system.
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
Introduction RT CORBA Dev. DOTS Project Conclusions
Domain of application
CORBA-IEDCORBA Gateway
Station Computer
CORBA-RTU
DOTS-010-1
RTORB Non RTORB
LN
LN LN
LN LN
LN
CORBA Gateway
Non CORBA-IED
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• The ELITEL-5 IEDs Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• The pilot application Introduction RT CORBA Dev. DOTS Project Conclusions
C ontro l Build ing C om m unication R oom
Build ing C R -1
O IT & SC T C om puter
H U B
H U BIED 1
IED 2
Substation C om puter Video C am era
R ing Button
R eal D ig ita l Input S ignals
R eal analog signals
S im ulate D ig ita l Input S ignals
S im ulate Analog S ignalsS im ulate D ig ita l O utput S ignals
R J-45 E thernet
R J-45 E thernet R J-45 E thernet
R J-45 E thernet
R G -59 v ideo cab le
O F
©SCILabs 2002
www.SCILabs.es
The DOTS Project
Elite
l 5
RTORB
Real-Time POA
Client Propagated Priority Model
Threadpools
ICa MinRT VisiBrokerOIT
IIO
P
Process
IEC-61850
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• Physical devices– OIT: Operator Interface Tool– IED1: Elitel 5 with blocking control– IED2: Elitel 5 with circuit breaker and switchs
• Logical Nodes– IHMI: Human-Machine Interface– XCBR: Circuit Breaker– XSWI: Switch– CILO: Inter-locking
OIT
IED2 IED1
XSWI25
XCBR20CILO0
IHMI0
3' 5'6
52
3
4
1
Supervision of analog and digital signals and digital refresh rate of 100ms
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS ProjectCaso 1: operación inhibida º
OIT. IHMI0 IED2. XCBR20 IED1. CILO0 IED2. XSWI25
t1 XCBR.set_ctlVal t2 CILO.get_stVal t3 XSWI.get_stVal t4 openedt5 disabledt6 rejected
Tramas Ethernet - GIOP (tiempos en microsegundos)us 1 2 3 4 5 6 7 8 9 10 media máx.t1 20.335.662 45.553.513 52.144.590 58.703.645 64.313.420 74.245.842 79.532.090 95.386.618 97.130.014 106.980.377t2 20.406.110 45.614.671 52.203.864 58.768.336 64.374.433 74.314.190 79.594.563 95.449.168 97.190.656 107.041.147t3 20.473.052 45.682.335 52.271.569 58.832.201 64.442.697 74.383.529 79.666.425 95.518.615 97.262.690 107.110.436t4 20.610.142 45.832.117 52.416.208 58.968.215 64.582.785 74.523.270 79.804.676 95.657.546 97.402.515 107.250.338t5 20.635.061 45.864.838 52.443.386 58.990.098 64.604.270 74.544.635 79.826.270 95.679.531 97.424.028 107.272.837t6 20.659.827 45.888.113 52.467.953 59.012.211 64.626.445 74.566.733 79.852.838 95.701.697 97.446.218 107.295.188t1-t2 70.448 61.158 59.274 64.691 61.013 68.348 62.473 62.550 60.642 60.770 63.137 70.448t2-t3 66.942 67.664 67.705 63.865 68.264 69.339 71.862 69.447 72.034 69.289 68.641 72.034t3-t4 137.090 149.782 144.639 136.014 140.088 139.741 138.251 138.931 139.825 139.902 140.426 149.782t4-t5 24.919 32.721 27.178 21.883 21.485 21.365 21.594 21.985 21.513 22.499 23.714 32.721t5-t6 24.766 23.275 24.567 22.113 22.175 22.098 26.568 22.166 22.190 22.351 23.227 26.568t1-t6 324.165 334.600 323.363 308.566 313.025 320.891 320.748 315.079 316.204 314.811 319.145 334.600
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
Caso 2: operación permitida
OIT. IHMI0 IED2. XCBR20 IED1. CILO0 IED2. XSWI25
t1 XCBR.set_ctlVal t2 CILO.get_stVal t3 XSWI.get_stVal t4 closedt5 enabled
IED2. SD1close
t6 accepted
us 1 2 3 4 5 6 7 8 9 10 media máx.t1 2.499.720 5.365.568 7.835.573 9.296.164 15.425.039 19.646.169 21.981.022 24.083.936 28.529.510 32.992.953t2 2.563.527 5.429.650 7.900.292 9.361.910 15.487.889 19.709.996 22.046.448 24.149.677 28.593.594 33.060.292t3 2.631.717 5.493.665 7.966.715 9.427.648 15.565.181 19.784.617 22.112.679 24.218.979 28.661.929 33.125.986t4 2.767.646 5.630.963 8.104.121 9.570.560 15.704.305 19.924.838 22.255.135 24.362.593 28.803.099 33.269.912t5 2.789.230 5.652.693 8.128.383 9.596.547 15.726.077 19.956.273 22.276.619 24.387.501 28.824.590 33.295.873t6 2.892.260 5.762.258 8.232.135 9.698.891 15.829.857 20.064.049 22.386.585 24.492.481 28.930.021 33.405.228t1-t2 63.807 64.082 64.719 65.746 62.850 63.827 65.426 65.741 64.084 67.339 64.762 67.339t2-t3 68.190 64.015 66.423 65.738 77.292 74.621 66.231 69.302 68.335 65.694 68.584 77.292t3-t4 135.929 137.298 137.406 142.912 139.124 140.221 142.456 143.614 141.170 143.926 140.406 143.926t4-t5 21.584 21.730 24.262 25.987 21.772 31.435 21.484 24.908 21.491 25.961 24.061 31.435t5-t6 103.030 109.565 103.752 102.344 103.780 107.776 109.966 104.980 105.431 109.355 105.998 109.966t1-t6 392.540 396.690 396.562 402.727 404.818 417.880 405.563 408.545 400.511 412.275 403.811 417.880
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• Some results– DOTS is the first implementation
of the IEC-61850 standard– Contribution to the adoption of
the IEC-61850 standard• General Model Definition• Specific Communication Service
Mapping-Mapping to CORBA
– Embedded IEC-61850 SW for IED and RTU over the SCILabs’ ICa ORB
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• Real-time ICa• An SCT and OIT capable to
manage IEC-61850 objects
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
The DOTS Project
• Some results of SCILabs Introduction RT CORBA Dev. DOTS Project Conclusions
Version: Release ICA ORB Performance TestServer: LunesClient: BelcebubNumber of Calls: 1000
ORBSequence of Octets
Sequence of Shorts
Sequence of Octets
Sequence of Shorts
Sequence of Octets
Sequence of Shorts
Sequence of Octets
Sequence of Shorts
ICA (SCILabs) 1132 1132 1342 1352 5568 5569 10275 10276VISIBROKER (Borland) 1352 1262 1492 1482 5698 5669 10375 10386TAO (Washington University) 1600 1600 1600 1600 6400 6400 11600 11240ORBIX/E (Iona) 1052 1042 1272 1261 5549 5548 10296 10495EORB (Vertel) 861 862 1071 1082 5229 5728 10797 10495
144
DataSize in bytes
OneWay TwoWay4816
OneWay TwoWay
©SCILabs 2002
www.SCILabs.es
Speech Contents
• Introduction• Real-Time/Minimum CORBA
Development• The DOTS Project• Conclusions
©SCILabs 2002
www.SCILabs.es
Conclusions
• Real-Time CORBA is beginning to be used by the RT/embedded systems community
• There is need for an embedded CORBA specification
• Battle to improve performance, footprint and ORB determinism
Introduction RT CORBA Dev. DOTS Project Conclusions
©SCILabs 2002
www.SCILabs.es
Conclusions
Thank you!
Introduction RT CORBA Dev. DOTS Project Conclusions