Summary and Credit - luckyphil/nonstop-jni GitHub Wiki

The original requirement was to obtain the current time as a TIMESTAMP (48 bit) - this is a NonStop Guardian O/S specific that has a zero at 31/12/1974. So the obvious was to use JNI to call a 'C' function that invokes the Guardian Proc call for TIMESTAMP( short _near * t).

The NonStop Java environment (and we're using H-Series here which has dynamic .so libs) has an example of JNI in /usr/tandem/java/demo/javahjni and this gave the basic compiler and linker (/usr/bin/c89 and /usr/bin/eld) options as well as a working example.

The next task was to make it easy to build, re-build and manage in an ongoing manner. Credit here goes to a blog by M. Fraass http://www.tricoder.net/blog/?p=197 which identified and demonstrated how to really make the http://mojo.codehaus.org/maven-native/native-maven-plugin/ work well in a modular way.

Added to this was a junit test that can be extended as and when other Guardian functions are implemented. The package has been named org.itug.nonstopjni as it is a natural fit with other elements of the NonStop ituglib. ituglib is a user group library - legacy name I guess for international tandem user group. The site for ituglib is part of hp connect at http://ituglib.connect-community.org/apps/Ituglib/HomePage.jsf

I'd envisage that the existing class GuardianProcedure.java would implement the simple calls such as TIMESTAMP, CONTIME etc. Not restricting it to time manipulation, but not wanting to see this class grow unbounded. The build framework using maven will easily allow the creation of additional, more specialised classes along with additional library calls.

Thanks to Simon and Abu who helped me get this working.