putMarker doesn't seem to work - after executing the CLEventList still has a length of 0, thus putWaitForEvents() fails. I presume it's missing a call to CLEventList.createEvent() from looking at the other functions that generate events. I tried updating using git - but i don't know if it actually updated it, or simply broke the build, but either way I an unable to compile the code to test it to generate a patch.
i managed to get it it to build, adding a createEvent invocation fixes it.
Thanks for the report and the fix. I'll integrate it soon and add a regression test.
fixed. will be available in next build. https://github.com/mbien/jocl/commit/f2eb78947c79d09dbe19e56b03da4119013e8e0e