JNA crash

Question

Hi,
I am currently working on a project using a C (MSVC) DLL trhough JNI and I want to switch to JNA but I experience some problems, some functions just make the VM to crash.
eg:
The C prototype from the header:
short STDCALL SERVERRemoteControlRequest (short session_id, char devId, long t_offset, short Forced, short *Accept, short *Token);My JNA interface:
public interface LibNexus extends Library {
     LibNexus INSTANCE = (LibNexus) Native.loadLibrary("NexusSDK", LibNexus.class);
     LibNexus SYNC_INSTANCE = (LibNexus) Native.synchronizedLibrary(INSTANCE);
        short SERVERRemoteControlRequest (short sessionId, char devId, long t_offset, short Forced, ShortByReference Accept, ShortByReference Token);
}The code leading to VM crash:
ShortByReference Accept = new ShortByReference();
ShortByReference Token = new ShortByReference();
ret = lib.SERVERRemoteControlRequest((short)0, (char)0, 1L, (short)0, Accept, Token);Here is what I get when I run it:
# An unexpected error has been detected by Java Runtime Environment:
#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x030460fd, pid=3200, tid=2864
# Java VM: Java HotSpot(TM) Client VM (10.0-b19 mixed mode, sharing windows-x86)
# Problematic frame:
# C  [NexusSDK.dll+0x60fd]
# An error report file with more information is saved as:
# C:\Documents and Settings\bboucher\Bureau\Ben\workspace\jnexus\hs_err_pid3200.log
# If you would like to submit a bug report, please visit:
#   http://java.sun.com/webapps/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#I just put one example but there are many functions that crash the VM, while many functions work perfectly.
Is it possible that some functions from a DLL just don't work with JNA while others do ? (All functions are doing fine with JNI).

Answer 1

>
The C prototype from the header:
short STDCALL SERVERRemoteControlRequest (short session_id, char devId, long t_offset, short Forced, short *Accept, short *Token);My JNA interface:
public interface LibNexus extends Library {
     LibNexus INSTANCE = (LibNexus) Native.loadLibrary("NexusSDK", LibNexus.class);
     LibNexus SYNC_INSTANCE = (LibNexus) Native.synchronizedLibrary(INSTANCE);
short SERVERRemoteControlRequest (short sessionId, char devId, long t_offset, short Forced, ShortByReference Accept, ShortByReference Token);
According to the FAQ from the JNA home page, you need to check your calling convention and parameter sizes. Based on the documentation for calling convention and type mapping:
1) STDCALL ==> "StdCallLibrary", not Library
2) native long ==> "NativeLong" or "int" on Windows (32 bits), not Java long (64 bits)
3) native char ==> Java byte
4) there is a mailing list devoted to these sorts of questions, users AT jna DOT dev DOT java DOT net.