Application Unexpectedly Quits - Suspect JNI

Question

We have a Java application that communicates with a spectrophotometer via USB - the device and USB support is through a third party JAR that uses JNI. While the application runs on both Windows and Macintosh, often the application unexpectedly quits on the Macintosh, usually invoking the Apple "do you wish to send the crash results to Apple" dialog.
Inspecting our own application log files we can't see any reason for the application quitting. Sometimes we are using he spectrophotometer, sometimes not. Inspecting the Apple Java crash logs, more than half the time they indicate a problem in the native interface. The problem seems to have started after moving from JSE 1.3 to JSE 1.4.
Unfortunately there is not enough information afterwards to indicate what the problem is. Are there tools or techniques for investigating this problem further? We seen to be at an impass and need to ship the Application soon to customers.

Answer 1

While running the Application on the Mac I used the
following VM options: -verbose:jni -Xcheck:jni
I noticed the following message a lot of times
Warning: Calling other JNI functions in the scope of
Get/ReleasePrimitiveArrayCritical or
Get/ReleaseStringCritical
Is this something I should worry about? If it was me I would.
What does it
mean exactly?You are using a piece of the java heap that has been locked down. And then you are calling other java methods expecting them to work normally. I believe those specific methods warn against that.
The following link repeats what I said....
http://java.sun.com/j2se/1.3/docs/guide/jni/jni-12.html#GetPrimitiveArrayCritical