EngineCallBacks.queryInterrupt
queries if Maple should interrupt computation
Calling Sequence
Parameters
Description
Examples
boolean queryInterrupt( Object data ) throws MapleException
data
-
arbitrary data that was passed into the Engine constructor
queryInterrupt is a member function of the com.maplesoft.openmaple.EngineCallBacks interface. It allows the Java OpenMaple programmer to interrupt the Maple engine during computation. queryInterrupt is called periodically while the Maple engine is running. If queryInterrupt returns true then Maple interrupts the computation.
import com.maplesoft.openmaple.*;
import com.maplesoft.externalcall.MapleException;
class Example
{
static private class CallBacks implements EngineCallBacks
double last;
boolean limitExceeded;
CallBacks()
last = 0.0;
limitExceeded = false;
}
public void textCallBack( Object data, int tag, String output )
throws MapleException
switch ( tag )
case MAPLE_TEXT_OUTPUT:
System.out.print( "Text: " );
break;
case MAPLE_TEXT_DIAG:
System.out.print( "Diag: " );
case MAPLE_TEXT_MISC:
System.out.print( "Misc: " );
case MAPLE_TEXT_HELP:
System.out.print( "Help: " );
case MAPLE_TEXT_QUIT:
System.out.print( "Quit: " );
case MAPLE_TEXT_WARNING:
System.out.print( "Warning: " );
case MAPLE_TEXT_DEBUG:
System.out.print( "Debug: " );
System.out.println( output );
public void errorCallBack( Object data, int offset, String msg )
if ( offset >= 0 )
throw new MapleException( "Error: "+msg );
else
throw new MapleException( "syntax error at offset "+offset+
": "+msg );
public void statusCallBack( Object data, long kbused, long kballoced,
double timeused )
if ( timeused > 5 )
limitExceeded = true;
if ( timeused-last > 1 )
System.out.println( "Status: used = "+kbused+", alloced = "+
kballoced+", time = "+timeused );
last = timeused;
public String readLineCallBack( Object data, boolean debug )
return "readline";
public boolean redirectCallBack( Object data, String output, boolean
append )
System.out.println( "redirect to "+output+" append = "+append );
return true;
public String callBackCallBack( Object data, String output )
System.out.println( "callback: "+output );
return output+";";
public boolean queryInterrupt( Object data )
return limitExceeded;
public String streamCallBack( Object data, String name, String args[] )
StringBuffer sbuf;
int i;
sbuf = new StringBuffer( name );
for ( i = 0; i < args.length; i++ )
sbuf.append( args[i] );
return sbuf.toString();
public static void main( String notused[] ) throws MapleException
String mapleArgs[];
Engine engine;
Algebraic a;
mapleArgs = new String[1];
mapleArgs[0] = "java";
engine = new Engine( mapleArgs, new CallBacks(), null, null );
for ( i = 0; i < 10000000; i++ )
a = engine.evaluate( "Array( 1..10^5 ):" );
if ( a == null )
a.dispose();
System.out.println( "i's value when finished: "+i );
Executing this code produces output similar to the following.
Status: used = 45963, alloced = 1503, time = 1.01
Status: used = 105566, alloced = 1503, time = 2.02
Status: used = 164192, alloced = 1503, time = 3.0300000000000002
Status: used = 224771, alloced = 1503, time = 4.05
i's value when finished: 2880
See Also
ExternalCalling/Java/MapleException
OpenMaple
OpenMaple/Java/Engine
OpenMaple/Java/Engine/Engine
OpenMaple/Java/EngineCallBacks
OpenMaple/Java/EngineCallBacksDefault
OpenMaple/Java/EngineCallBacksDefault/queryInterrupt
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