NetMorph

An intuitive mobile object system andits applications

Masashi Umezawa Kazuhiro AbeSatoshi Nishihara Tetsuya Kurihara

January 30, 2003

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Table of contents

• Problems of networking• NetMorph design and

implementation• Conclusion and future plan

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Problems of the present networking

• Most network systems do not provide proper intuitive interfaces for us– Users have to acquire specific

knowledge depending on various protocols

• In many cases, users can only use prepared network applications

• Developing their own distributed programs is tremendously difficult

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• Morphic and SqueakToys are great environment for developing computer literacy of non-technical people

• But… – They do not support network applications

• NetMorph provideslogical broad spaces, where users can create network applications freely

What NetMorph aims at

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Basic concepts

• Each morph has its own “network location”• The location of Morph is represented by the

combination of 2D coordinates and logical network address

• Morph can move toother desktops, simplychanging its locationvalues

• Desktop relations aredefined by “WorldMap”

0, 00, 0

x

y

0, 0

↓ 62.38.0.32

1, 0

↓ 202.3.12.76

0, 1

↓ 173.234.54.4

1, 1

↓ 142.41.65.42

x

y

0, 0

↓ 62.38.0.32

1, 0

↓ 202.3.12.76

0, 1

↓ 173.234.54.4

1, 1

↓ 142.41.65.42

：

・・

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NetMorph script examples

MyCar forward by 5MyCar turn by 5MyCar warp

MyCar warp tosomehostMyCar’s homeMyFriend’s address

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Table of contents

• Problems of networking• NetMorph design and

implementation• Conclusion and future work

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Migration (‘warp drive’) mechanism (1)

1. A Morph remembers a current desktop location for the later x y adjustments

2. The Morph serializes itself3. The Morph sends the serialized data to the d

estination desktop by NMP (NetMorph Protocol)

4. The System invokes a ‘warpedOut’ event handling method that is usable for additional user defined behaviors

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Migration (‘warp drive’) mechanism (2)

x

y

12

0101110101011001001001001001

NMP3

warpedout!

40101110101011001001001001001

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Migration (‘warp drive’) mechanism (3)

5. A migration server (called Catcher) receives the serialized data and deserializes it to the Morph

6. The Catcher adjusts the Morph position7. The system attaches the Morph to the destination d

esktop. The Morph begins to move in the new desktop

8. The System invokes a ‘warpedIn’ event handling method for additional user defined behaviors

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Migration (‘warp drive’) mechanism (4)

5

x

y

67

warpedin!

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0101110101011001001001001001

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Serialization in warp

• SmartRefStream– Simple– Automatic class migration– But big and slow

• We may develop a customized serializer…

0101110101011001001001001001

0101110101011001001001001001

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Network communication between Morphs

Another World

Joystick Proxy of Joystick

message returnValue

message

returnValue

Original World

warp

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Finding a morph in networks (1)

1. Local ActiveWorld is searched.2. If a Morph is found, the Morph is returned to

the caller. If not, local cache is searched3. If found in cache, a cached Morph proxy is re

turned. If not, remote servers that are registered in WorldMap are searched

4. If found, a Morph proxy is returned to the caller. If not, nil is returned

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proxy

Finding a morph in networks (2)

found

not found

localcache

found

WorldMap

found

not found

not found

nil

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Filtering the targets

• AvailabilityChecker periodically checks if the registered entries of WorldMap are reachable

• Finder only sees AvailabilityChecker’s available entry list

Available Entry List

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Finding a remote player in networks

• Customized script generator– Now Players can always refer to other

Players by identifier

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Remote message sending between morphs

aMorph(joystick)

aNmMorphProxy

1. message

2. doesNotUnderstand:

3. xxxCallWithArgumentsDispatch: target:

aNmRemoteConnecter

4. callDispatch:to:selector:withArguments:

aNmDispacher

5. dispatch:to:selector: withArguments:6. message

aMorph(car)

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WorldMap management

• A MapServer provides a latest map data for NetMorph clients

• Each NetMorph image periodically retrieves the CSV map data from a MapServer

• We can edit a map datagraphically by using a WorldMapMorph

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NetMorph protocol (NMP)

– Compact• No tags• Binary

– Fast• Connection pooling

– Simple‘NMP<version>’ ’<semantic>’ ’<command>’ ‘<encoder>’ *’<size>’!’Binaries…

BodyHeader

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Live demos

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Table of contents

• Problems of networking• NetMorph design and implementation• Conclusion and future work

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Conclusion

• As you can see, NetMorph is fun!– In Smalltalk, everything is object– In NetMorph, everything is live network object

• We had thought that it may be only a dream. But as the project proceeds, we’ve realized that it is possible in a few years

• In spite of the naïve implementation, NetMorph works beyond our expectation!

• Need to develop communities– More field tests– Utilize open source power

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Field tests

• We have not done any serious field-testing yet…

• But, we are planning to perform a field test with children on Feb. 2nd 2003 at CAMP

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The next goals

• More tight integration with SqueakToys– Quality– Performance– Functionality

• Slogan

– “What can do in SqueakToys is what can do in NetMorph”

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Developing communities

• Helping Kyoto Alan Kay Project• Demonstration in OOPSLA 2002• NetMorph Swiki

– http://swikis.ddo.jp/NetMorph

• SqueakMap– NetMorph will be available on SM in March

2003

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Any questions?