There may be an alternative.

I m doing something similar: In an application I monitor 4 mice for clicks. Those clicks generate interrupts but I m happy enough not to deal with them directly from Java.

Under Linux, it turns out there are device files (/dev/input/mouse#) that spew a bunch of characters when something happens with the mouse. I have a Thread for each one with a FileReader blocking on a read. Once characters arrive, the appertaining thread unblocks and I can do whatever processing I like.

So the idea is: If possible, find a way to get a device driver to make the data accessible to you in file/device form, then you can access it from Java using just IO calls from the Java library, with no weird bit-twiddling code and C required in between.

In principle yes, but it will require some C code and JNI to tie that to Java. If you are very lucky perhaps already someone has already built a suitable library for the paltform you are interested in.

Bottom line: if it can be done in C you can hook that to Java.

If you would like to directly respond to an interrupt from Java, then the VM would have to run in kernel space (or on some systems with user space drivers, in a driver context). The JamaicaVM runs in this mode on some RTOSes such as Thread-X or VxWorks as a DKM. The next release of the RTSJ will support writing interrupt service routines in Java.

The RTSJ can be used to run second level interrupt handlers even in user space. This requires a small device driver that either sends a POSIX signal to the VM or provides a character device interface where one thread in the VM blocks on a read of the device. In the first case, an AsyncEventHandler can be assoicated with the POSIX signal. In the second, the tread that blocks on a read of the device can fire an AsyncEvent each time a byte is read from the device. Then any AsyncEventHandler attached to the AsyncEvebt would be released.

If you would like to try this under Linux, you can download the JamaicaVM personal edition: "http://www.aicas.com/jamaica-pe.html". JamaicaVM has a realtime garbage collector and code can be compiled statically to ensure realtime performance. This is a different deployment model than a conventional JVM.

Here is a paper that handles the same topic. And you may have a look at SWT, I think they re dealing with hardware interrupts aswell, although they may rely on the operating systems API.

It s standard on embedded realtime java. go to www.ajile.com, or systrmonx.com and buy an eval board.

Embedded java is not standard on pc s. you can get realtime java on PC hardware, but not the embedded bit.

Take a look at Swig. The Java implementation has Directors that will allow you to call into Java from C/C++.

I ve used this technology to handle interrupts calling into C#, and it worked great. Shouldn t be much different calling Java.