Transcript Planning and Optimisation

Interfacing & embedding
1
References
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Full tutorial and references
Embedding and Interfacing Manual
Windows - select “Documentation” from the ECLiPSe
entry in the “start” menu
Unix - access the file “doc/index.html” under the
ECLiPSe installation directory

Examples
The “doc/examples/” directory under the ECLiPSe installation
directory
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Overview
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Languages
General execution model
Architecture
Embedded / Remote
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Language specifics
Example
References (again)
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Languages
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Java
C
C++
Tcl
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External programs
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General execution model
ECLiPSe
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Synchronous
Control token passing
Explicit and Implicit
ECLiPSe goals bind variables
RPC for simple goals
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Queues/Streams for data
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Peer
post goal
goal returns
resume()
yield()
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Architecture
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Embedded
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Java
Tcl
External program
Java
C(++)
Tcl
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Run within the same
operating system process
Data structures can be
shared
Remote (ERIP)
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Run in a separate
operating system process
Communication over
sockets
Data structures must be
converted
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C(++) Embedding
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ECLiPSe engine encapsulates the state of computation
Single instance
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The only interface where ECLiPSe can explicitly call
functions defined in the “peer” language
The only interface where non-deterministic goals are
handled implicitly
Some care must be taken with memory management
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Java/ECLiPSe interface
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Implements one side of the ERIP
Common interface for embedded & remote
Initialisation/shutdown differs
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Single Java thread per ECLiPSe instance
Blocks when ECLiPSe has control
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Data passing over queues/streams
Automatic conversion
Can pass control by specifying QueueListener
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Java/ECLiPSe interface
ECLiPSe
atom
Java
Atom
compound
CompoundTerm
integer
java.lang.Integer
integer
java.lang.Long
list
java.lang.Collection
float
java.lang.Double
float
java.lang.Float
string
variable
java.lang.String
null
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Remote Predicate Call
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Java side supplies goal term to RPC method
ECLiPSe executes goal: three possible outcomes
Goal succeeds
Goal with satisfying substitutions is returned to Java
All subsequent solutions are cut
Goal fails
Java throws Fail exception
Goal causes ECLiPSe exception
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Java throws Throw exception
Same mechanism used in other interfaces
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Data transfer using EXDR
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Eclipse eXternal Data Representation
Serializable
Represents types which are common across interface
ECLiPSe-side support:
write_exdr/2
(to any stream)
read_exdr/2 (from any stream)
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Java-side support:
EXDRInputStream
EXDROutputStream
(wraps any InputStream)
(wraps any OutputStream)
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ECLiPSe support for ERIP
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Setup & teardown
remote_connect(?Address, ?Peer, ?InitGoal)
remote_disconnect(+Peer)
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Queue/stream management
peer_queue_create/5
peer_queue_close/1
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Sending data
Treat queues as normal ECLiPSe streams
May be asynchronous
Control is transferred when flush/1 is called
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External programs
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External program started with
exec(++Command, +Streams, ?Pid)
Command takes list of atomic terms
Binds stdin, stdout & stderr to the specified Streams
Returns process id in Pid
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Communication over streams
Wait for termination with
wait(?Pid, ?Status)
Pid (process id) to wait for
Termination Status
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Embedded ECLiPSe example
import com.parctechnologies.eclipse.*;
import java.io.*;
public class QuickTest {
public static void main(String[] args) throws Exception {
// Create some default Eclipse options EclipseEngineOptions
eclipseEngineOptions = new EclipseEngineOptions();
// Object representing the Eclipse engine
EclipseEngine eclipse;
// Connect the Eclipse's standard streams to the JVM's
eclipseEngineOptions.setUseQueues(false);
// Initialise Eclipse
eclipse = EmbeddedEclipse.getInstance(eclipseEngineOptions);
// Write a message
eclipse.rpc("write(output, 'hello world'), flush(output)");
// Destroy the Eclipse engine
((EmbeddedEclipse) eclipse).destroy();
}
}
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External program example
exec([ls,"-C"], [null, out], Pid).
Pid = 10885
yes.
repeat, get(out,X), (X = -1 -> close(out) ; put(X), fail).
aux.o coroutine.pl
kegi.pl
sepia.o
bsi.pl
cprolog.pl
lint.pl
sorts.pl
cio.pl
history.pl
lists.pl strings.pl
cn.pl k_env.pl quintus.pl
t_all.pl
X = -1
wait(S, Pid).
Pid = 10885
S = 10885
yes.
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References

Full tutorial and references
Embedding and Interfacing Manual
Windows - select “Documentation” from the ECLiPSe entry in the
“start” menu
Unix - access the file “doc/index.html” under the ECLiPSe installation
directory

Examples
The “doc/examples/” directory under the ECLiPSe installation
directory
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