JNI code is NOT zIIP-eligible. For significant pathlength or frequent calling that probably matters a great deal.
Cheers, Martin Martin Packer, zChampion, Principal Systems Investigator, Worldwide Banking Center of Excellence, IBM +44-7802-245-584 email: martin_pac...@uk.ibm.com Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker From: Phil Smith <p...@voltage.com> To: IBM-MAIN@listserv.ua.edu Date: 12/06/2014 20:10 Subject: JNI on z/OS Sent by: IBM Mainframe Discussion List <IBM-MAIN@listserv.ua.edu> This post will reveal (a small fraction of) my vast ignorance, so for those who know what JNI is, might be worth reading if just for entertainment value. We have a very simple API that we'd like to enable for use from WAS applications on z/OS. Currently we support any standard language that calls us with an OS/360-style plist, passing pointers to character strings and to fullword lengths of those strings. The API is assembler, and doesn't do much: a bit of validation, and then a PC over to a started task. Let's pretend it's a REVERSE function, so gets called (from C): rc = reverse(string, length); >From my reading, it appears that JNI is the way to go here. I know that JNI is considered A Bad Thing (to quote my manager), but reading http://en.wikipedia.org/wiki/Java_Native_Interface#Pitfalls doesn't leave me concerned-none of those seem like anything that will affect us. Some Googling finds Integrating Java with Existing Data and Applications on OS/390 (SG24-5142-00), which is from 1998 (!) and Java Stand-alone Applications on z/OS Volume II (SG24-7291-00), which is "only" 8 years old. But presumably this stuff still applies. So it all seems pretty straightforward, but if someone had a trivial example they could share, that would help. Questions: 1) Is it reasonable to expect that a Java program running in batch (assuming that's even a possible environment?) could use the same JNI shims? 2) What other pitfalls should we expect? 3) What questions am I not asking that I should be? Thanks, ...phsiii ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
