6.3 Jasper Package Options

The following Java system properties can be set to control some features of the Jasper package:

se.sics.jasper.SICStus.checkSPTermAge

This flag is unsupported.

A boolean, true by default. If true, run-time checks are performed that attempt to detect potentially dangerous use of the SPTerm.putXXX family of functions. The value of this flag can be set and read with SICStus.setShouldCheckAge() and SICStus.shouldCheckAge(). This flag was false by default in SICStus 3.8.

The run-time checks throws an IllegalTermException when there is risk that a SPTerm is set to point to a Prolog term strictly newer than the SPTerm. In this context strictly newer means that there exists an open query that was opened after the SPTerm object was created but before the Prolog term. See SPTerm and Memory, for more information:

          % java -Dse.sics.jasper.SICStus.checkSPTermAge=true ...
     

or, from Prolog:

          jasper_initialize(
             ['-Dse.sics.jasper.SICStus.checkSPTermAge=true'],
             JVM)
     

se.sics.jasper.SICStus.reuseTermRefs

This flag is unsupported.

A boolean, on by default. If false, SPTerm.delete() will only invalidate the SPTerm object, it will not make the Prolog side SP_term_ref available for re-use. The value of this flag can be set and read with SICStus.setReuseTermRefs() and SICStus.reuseTermRefs(). There should be no reason to turn it off.

To set this flag do:

          % java -Dse.sics.jasper.SICStus.reuseTermRefs=true ...
     

or, from Prolog:

          jasper_initialize(
             ['-Dse.sics.jasper.SICStus.reuseTermRefs=true'],
             JVM)
     

se.sics.jasper.SICStus.debugLevel

This flag is unsupported.

You probably should not use it in production code. It may be removed or change meaning in future releases.

An integer, zero by default. If larger than zero, some debug info is output to System.out. Larger values produce more info. The value of this flag can be set and read with SICStus.setDebugLevel() and SICStus.debugLevel():

          % java -Dse.sics.jasper.SICStus.debugLevel=1 ...
     

or, from Prolog:

          jasper_initialize(
             ['-Dse.sics.jasper.SICStus.debugLevel=1'],
             JVM)