AV when using JNI

Question

Hi,
We have faced a problem that is very similar to the one reported in this thread:
http://forums.bea.com/bea/message.jspa?messageID=200010160&tstart=0
Has the problem been fixed in a later release?
We are using BEA JRockit 5.0 R26.4.0-63 under Windows XP Professional 32-bit SP2 and still get Access Violations when using java.lang.Class.getDeclaredMethods() or java.lang.Class.getDeclaredFields(). The exception does not occur when we use the same module with Sun JVM and MS JVM.
If the problem is supposed to be fixed, I can provide more details.
Best regards,
Alex
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Answer 1

Hello Staffan,
Thanks for your reply. Here is a description of the first problem we have faced:
When using JNI to call the java.lang.Class.getDeclaredMethods() or java.lang.Class.getDeclaredFields() method, we get the java.lang.NullPointerException exception in some cases. If we debug the java.exe process in Visual Studio 2005, we can see that the following exception occurs:
First-chance exception at 0x7d612b73 in java.exe: 0xC0000005: Access violation reading location 0x00000010.
Here is a part of the exception call stack:
7d612b73()
jvm.dll!_stubsCallC2JavaStub() + 0x24 bytes
jvm.dll!_callC2Java() + 0x309 bytes
jvm.dll!_jniCheckExceptionsForCall() + 0x12e bytes
jvm.dll!_jniCallObjectMethodA@16() + 0x3b bytes
jvm.dll!_jniGetVersion@4() + 0x993 bytes
tcJavaHook.dll!JNIEnv_::CallObjectMethodA(_jobject * obj=0x34960204, _jmethodID * methodID=0x77b84b08, const jvalue * args=0x00000000)  Line 879 + 0x1f bytes C++
We have done some investigations and found out that the problem occurs for the following classes:
java.lang.Class, javax.swing.JPanel, javax.swing.JLayeredPane, javax.swing.JToolBar, javax.swing.AbstractButton, javax.swing.JLabel,
javax.swing.JScrollPane, javax.swing.JViewport, javax.swing.JTable, javax.swing.CellRendererPane, javax.swing.JScrollBar, javax.swing.table.JTableHeader, javax.swing.JMenuBar, javax.swing.JComboBox, javax.swing.JSpinner, javax.swing.text.JTextComponent
While the exception does not occur when calling methods of the following classes:
javax.swing.JFrame, java.awt.Frame, javax.swing.JComponent, javax.swing.JRootPane, java.lang.Object, java.awt.Component, java.awt.Container, java.awt.Window, java.awt.Dialog, javax.swing.JDialog
We were able to reproduce the problem with Eclipse 3.1.2 launched in the following way:
I:\Java\jrockit-R26.4.0-jdk1.5.0_06\jre\bin\java.exe -Xms40m -Xmx256m -jar D:\Eclipse\startup.jar -os win32 -ws win32 -arch x86 -launcher D:\Eclipse\eclipse.exe -name Eclipse -showsplash 600 -exitdata 14a8_60 -vm I:\Java\jrockit-R26.4.0-jdk1.5.0_06\jre\bin\java.exe -vmargs -Xms40m -Xmx256m -jar D:\Eclipse\startup.jar
I:\Java\jrockit-R26.4.0-jdk1.5.0_06\ - the installation folder of JRockit JDK
D:\Eclipse\ - the root folder of Eclipse
In this case, even trying to get information about the java.lang.Object class fields and methods causes the problem.
Can you say anything based on the above call stack?
Please let me know if you need any details about the problem.
Best regards,
Alex
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