[Wrapper-user] JVM crash using wrapper and custom JNI

[Jason P. <jas...@gm...>]

Hello all,

I am using the wrapper to launch a java app which loads a native library of
my own creation.  When running outside the wrapper, my native code
initialises and terminates successfully, and always has.  When I run this
same app within the wrapper, the JVM crashes when I am terminating my native
resource.

The native code I have is loading a COM DLL, and when my java app closes it
releases an unloads the COM DLL.  It is during this process that I get the
JVM crash.

Crash details are:

jvm 1    | #
jvm 1    | # An unexpected error has been detected by HotSpot Virtual
Machine:
jvm 1    | #
jvm 1    | #  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x1900507f,
pid=1168, tid=3016
jvm 1    | #
jvm 1    | # Java VM: Java HotSpot(TM) Server VM (1.5.0_09-b01 mixed mode)
jvm 1    | # Problematic frame:
jvm 1    | # C
jvm 1    |   [JSAVI2.dll+0xb507f]
jvm 1    | #
jvm 1    | # An error report file with more information is saved as
hs_err_pid1168.log
jvm 1    | #
jvm 1    | # If you would like to submit a bug report, please visit:
jvm 1    | #   http://java.sun.com/webapps/bugreport/crash.jsp
jvm 1    | #
wrapper  | JVM exited unexpectedly while stopping the application.

You will see that the "Problematic frame" is reported as JSAVI2.dll.  This
is my native DLL which loads/unloads the COM DLL.

The call stack in the JVM error report looks like this:

Stack: [0x19780000,0x197c0000),  sp=0x197bee20,  free space=251k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native
code)
C  [JSAVI2.dll+0xb507f]
C  [JSAVI2.dll+0xb7259]
j  com.synetek.virus.scanner.JSavi.releaseSAVI
(Lcom/synetek/virus/scanner/ScannerLog;)V+0
j  com.synetek.virus.scanner.JSavi.destroy
(Lcom/synetek/virus/scanner/ScannerLog;)V+9
j  com.synetek.everymail.core.handler.PipelineHandler.destroy()V+27
j  com.synetek.event.EventProcessor.destroy()V+43
j  com.synetek.processor.MultiProcessor.destroy(J)V+41
j  com.synetek.processor.ManagedMultiProcessor.stop(J)V+9
j  com.synetek.everymail.core.pipeline.poll.PipelinePoller.destroy()V+12
j  com.synetek.poller.AbstractPoller.stop(J)V+78
j  com.synetek.poller.remote.RemoteController.stop(J)V+5
v  ~StubRoutines::call_stub
V  [jvm.dll+0xf96e0]

You can see that my call to "releaseSAVI" is where the crash occurs.

Ordinarily I would assume that there is something wrong with my DLL, but it
has been working correctly until now.  I have checked and double-checked the
implementation of this native method in the C++ code and I cannot see how or
why I should be experiencing any problems (the native method is only 3 lines
of code!).

As stated, when I run my app in straight java land all is well.  I have
tried to debug my JNI DLL from Visual Studio, but the only way I know to do
this is to "attach" to the java.exe process from within Visual Studio.
Problem is that because java.exe crashes I don't get an opportunity to step
through the execution of the native code.

I'm a bit stuck here as there doesn't appear to be anything I can to short
of not using the wrapper.  This leaves me in the unenviable position of
having to write my own (urgh).

Have tried disabling HotSpot.. same problem.

Anyone have any ideas?

Thanks.