JVM Crash When Using JNI and COM

Question

I'm trying to call a DLL compiled from VB6 source code that I do not have access to. The VB6 code simply retrieves data from a DB2 database using ADO and my client code grabs that data and marshals it to my Java code. I'm attempting to achieve this using JNI and COM (without a third-party bridge). It works 75% of the time, but the other 25% of the time, the JVM crashes with the usual Hotspot crash log containing an access violation exception. However, I don't know what in my C++ code (VC++ 8) could be causing this except for passing a "wild" pointer to the code lying underneath the COM object interface. If that is the case, I don't know how I am doing that.
The Java code that is calling my native method is running on Tomcat 5.5.25 and just to be safe, I am not allowing multiple threads to concurrently call the method in my JNI DLL (though I realize that this will kill performance). Once I can get past this problem, I'll do the COM interfacing on a worker thread in my native code so I don't screw up CoInitialize and CoUninitialize calls in the case the same thread is concurrently executing multiple calls to my native code.
I've noticed that in most cases, the JVM crashes during my call to the pClsAccount->OpenConnection method. However, my DLL isn't what is listed on the top of the call stack, which is why I suspect the passing of a wild pointer, though I'm just taking a guess at that. Does anyone have an idea as to what's going on ?
JNIEXPORT jobject JNICALL Java_CustomerInfo_nGetCustomerAccountInfo(JNIEnv *env, jobject customerInfo, jstring accountNumber, jstring iniFileName)
jboolean isCopy;
// Account info class and instance to be instantiated
jclass accountInfoCls = NULL;
jobject accountInfoObj = NULL;
// The constructor ID of the accountInfoCls
jmethodID ctorID = NULL;
// Pointer to the interface for the ClsAccount COM object
_clsAccount *pClsAccount = NULL;
HRESULT hr;
BSTR bstrIniFileName(L"");
try
const char *nativeAccountNumber = NULL;
if (accountNumber != NULL)
nativeAccountNumber = env->GetStringUTFChars(accountNumber, &isCopy);
else
jclass newExcCls;
env->ExceptionDescribe();
env->ExceptionClear();
newExcCls = env->FindClass("java/lang/IllegalArgumentException");
env->ThrowNew(newExcCls, "accountNumber passed in was null !");
return NULL;
// Initialization
variantt varConnectionSucceeded = variantt(false);
variantt varGetAccountInfoSucceeded = variantt(false);
variantt varAccountNumber = variantt(nativeAccountNumber);
bstrt bstrLastPaymentDate = bstrt();
bstrt bstrLastErrorMessage = bstrt();
bstrt bstrLastErrorNumber = bstrt();
jlong jTotalDue = NULL;
jlong jEstablishedDueDay = NULL;
jlong jLastPaymentAmount = NULL;
jstring jLastPaymentDate = NULL;
jstring jLastErrorMessage = NULL;
jstring jLastErrorNumber = NULL;
jthrowable jException = NULL;
const char *chLastPaymentDate = NULL;
const char *chLastErrorMessage = NULL;
const char *chLastErrorNumber = NULL;
long long totalDue;
long long lastPaymentAmount;
long establishedDueDateDay;
//Convert string from Java string to C string to VB string
const char *nativeIniFileName = NULL;
if (iniFileName != NULL)
nativeIniFileName = env->GetStringUTFChars(iniFileName, &isCopy);
else
jclass newExcCls;
env->ExceptionDescribe();
env->ExceptionClear();
newExcCls = env->FindClass("java/lang/IllegalArgumentException");
env->ThrowNew(newExcCls, "iniFileName passed in was null");
return NULL;
bstrIniFileName = comutil::ConvertStringToBSTR(nativeIniFileName);
CoInitialize(NULL);
// Create an instance of the COClass with the interface over it
hr = CoCreateInstance(__uuidof(clsAccount), NULL, CLSCTX_INPROC_SERVER, __uuidof(_clsAccount), (void **)&pClsAccount);
if (hr == S_OK)
varConnectionSucceeded.boolVal = pClsAccount->OpenConnection(&bstrIniFileName);
　
if (varConnectionSucceeded.boolVal == -1)
varGetAccountInfoSucceeded.boolVal = pClsAccount->GetAccountPaymentInformation(&(varAccountNumber.GetVARIANT()));
env->ReleaseStringUTFChars(accountNumber, nativeAccountNumber);
// Extract all available account information from the ClsAccount object
if (varGetAccountInfoSucceeded.boolVal == -1)
totalDue = pClsAccount->TotalDue.int64;
establishedDueDateDay = pClsAccount->EstablishedDueDateDay;
lastPaymentAmount = pClsAccount->LastPaymentAmount.int64;
bstrLastPaymentDate = pClsAccount->LastPaymentDate;
chLastPaymentDate = comutil::ConvertBSTRToString(bstrLastPaymentDate.GetBSTR());
jTotalDue = (jlong)totalDue;
jEstablishedDueDay = (jlong)establishedDueDateDay;
jLastPaymentAmount = (jlong)lastPaymentAmount;
jLastPaymentDate = env->NewStringUTF(chLastPaymentDate);
delete[] chLastPaymentDate;
pClsAccount->CloseConnection();
// Populate error fields if any errors occur
bstrLastErrorMessage = pClsAccount->LastErrMessage;
chLastErrorMessage = comutil::ConvertBSTRToString(bstrLastErrorMessage.GetBSTR());
bstrLastErrorNumber = pClsAccount->LastErrNumber;
chLastErrorNumber = comutil::ConvertBSTRToString(bstrLastErrorNumber.GetBSTR());
jLastErrorMessage = env->NewStringUTF(chLastErrorMessage);
jLastErrorNumber = env->NewStringUTF(chLastErrorNumber);
delete[] chLastErrorMessage;
delete[] chLastErrorNumber;
const char* clsName = "com/nuance/merchantsmutual/businessentities/CustomerAccountInfo";
// Find the Java class and the ID of its constructor
accountInfoCls = env->FindClass(clsName);
ctorID = env->GetMethodID(accountInfoCls, "<init>", "(JJJLjava/lang/String;Ljava/lang/String;Ljava/lang/String;)V");
jException = env->ExceptionOccurred();
if (jException != NULL)
env->ExceptionDescribe();
env->ExceptionClear();
//Release all resources associated with the ClsAccount instance
pClsAccount->Release();
//Instantiate the class with the given parameters
accountInfoObj = env->NewObject(accountInfoCls, ctorID, jTotalDue, jEstablishedDueDay, jLastPaymentAmount, jLastPaymentDate, jLastErrorMessage, jLastErrorNumber);
jException = env->ExceptionOccurred();
if (jException != NULL)
env->ExceptionDescribe();
env->ExceptionClear();
else if (hr == REGDB_E_CLASSNOTREG)
cout << "COM class not registered" << endl;
else if ( hr == CLASS_E_NOAGGREGATION)
cout << "COM class can't be aggregated" << endl;
else if (hr == E_NOINTERFACE)
cout << "No interface for COM class clsAccount" << endl;
else if (hr == E_POINTER)
cout << "*ppv pointer was NULL !" << endl;
else
cout << "Error occurred while creating COM object. HR is [" << hr << "]" << endl;
// Free the BSTR because a new one was returned with a call to comutil::ConvertStringToBSTR
SysFreeString(bstrIniFileName);
// Release the string when it's no longer needed. MUST call if string won't be used
// anymore or else a memory leak will occur
env->ReleaseStringUTFChars(iniFileName, nativeIniFileName);
CoUninitialize();
&#12288;
catch (_com_error &e)
cout << "Encountered an exception in GetCustomerAccountInfo: Error was " << e.ErrorMessage();
pClsAccount->Release();
catch (...)
pClsAccount->Release();
return accountInfoObj;
Edited by: Cthulhu76 on Jan 5, 2010 9:18 AM

Answer 1

0x49202400 JavaThread "ContainerBackgroundProcessor[StandardEngine[Catalina]]" daemon [_thread_blocked, id=5340, stack(0x49bf0000,0x49c40000)]
0x48a7e800 JavaThread "Thread-1" [_thread_in_native, id=5976, stack(0x48f00000,0x48f50000)]
0x48a0dc00 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=3072, stack(0x48c60000,0x48cb0000)]
0x48a09000 JavaThread "CompilerThread0" daemon [_thread_blocked, id=4988, stack(0x48c10000,0x48c60000)]
0x48a07c00 JavaThread "Attach Listener" daemon [_thread_blocked, id=3124, stack(0x48bc0000,0x48c10000)]
0x48a07000 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=2572, stack(0x48b70000,0x48bc0000)]
0x489f5c00 JavaThread "Finalizer" daemon [_thread_blocked, id=5752, stack(0x48b20000,0x48b70000)]
0x489f4c00 JavaThread "Reference Handler" daemon [_thread_blocked, id=2596, stack(0x48ad0000,0x48b20000)]
0x003c6000 JavaThread "main" [_thread_in_native, id=4252, stack(0x00820000,0x00870000)]
Other Threads:
0x489f0400 VMThread [stack: 0x48a80000,0x48ad0000] [id=5624]
0x48a18800 WatcherThread [stack: 0x48cb0000,0x48d00000] [id=1192]
VM state:not at safepoint (normal execution)
VM Mutex/Monitor currently owned by a thread: None
Heap
def new generation total 36288K, used 12762K [0x02940000, 0x050a0000, 0x07800000)
eden space 32256K, 34% used [0x02940000, 0x0343af58, 0x048c0000)
from space 4032K, 37% used [0x04cb0000, 0x04e2ba28, 0x050a0000)
to space 4032K, 0% used [0x048c0000, 0x048c0000, 0x04cb0000)
tenured generation total 483968K, used 7518K [0x07800000, 0x250a0000, 0x42940000)
the space 483968K, 1% used [0x07800000, 0x07f57958, 0x07f57a00, 0x250a0000)
compacting perm gen total 14080K, used 14016K [0x42940000, 0x43700000, 0x46940000)
the space 14080K, 99% used [0x42940000, 0x436f0320, 0x436f0400, 0x43700000)
No shared spaces configured.
Dynamic libraries:
0x00400000 - 0x0040f000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\bin\tomcat5.exe
0x7c800000 - 0x7c8c0000      C:\WINDOWS\system32\ntdll.dll
0x77e40000 - 0x77f42000      C:\WINDOWS\system32\kernel32.dll
0x77380000 - 0x77411000      C:\WINDOWS\system32\USER32.dll
0x77c00000 - 0x77c48000      C:\WINDOWS\system32\GDI32.dll
0x77f50000 - 0x77feb000      C:\WINDOWS\system32\ADVAPI32.dll
0x77c50000 - 0x77cef000      C:\WINDOWS\system32\RPCRT4.dll
0x76f50000 - 0x76f63000      C:\WINDOWS\system32\Secur32.dll
0x77ba0000 - 0x77bfa000      C:\WINDOWS\system32\MSVCRT.dll
0x7c8d0000 - 0x7d0cf000      C:\WINDOWS\system32\SHELL32.dll
0x77da0000 - 0x77df2000      C:\WINDOWS\system32\SHLWAPI.dll
0x76290000 - 0x762ad000      C:\WINDOWS\system32\IMM32.DLL
0x77420000 - 0x77523000      C:\WINDOWS\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.3790.3959_x-ww_D8713E55\comctl32.dll
0x6d7c0000 - 0x6da10000      C:\Program Files\Java\jre1.6.0_07\bin\client\jvm.dll
0x76aa0000 - 0x76acd000      C:\WINDOWS\system32\WINMM.dll
0x7c340000 - 0x7c396000      C:\WINDOWS\system32\MSVCR71.dll
0x6d270000 - 0x6d278000      C:\Program Files\Java\jre1.6.0_07\bin\hpi.dll
0x76b70000 - 0x76b7b000      C:\WINDOWS\system32\PSAPI.DLL
0x6d770000 - 0x6d77c000      C:\Program Files\Java\jre1.6.0_07\bin\verify.dll
0x6d310000 - 0x6d32f000      C:\Program Files\Java\jre1.6.0_07\bin\java.dll
0x6d7b0000 - 0x6d7bf000      C:\Program Files\Java\jre1.6.0_07\bin\zip.dll
0x6d570000 - 0x6d583000      C:\Program Files\Java\jre1.6.0_07\bin\net.dll
0x71c00000 - 0x71c17000      C:\WINDOWS\system32\WS2_32.dll
0x71bf0000 - 0x71bf8000      C:\WINDOWS\system32\WS2HELP.dll
0x71b20000 - 0x71b61000      C:\WINDOWS\system32\mswsock.dll
0x5f270000 - 0x5f2ca000      C:\WINDOWS\system32\hnetcfg.dll
0x71ae0000 - 0x71ae8000      C:\WINDOWS\System32\wshtcpip.dll
0x76ed0000 - 0x76efa000      C:\WINDOWS\system32\DNSAPI.dll
0x76f70000 - 0x76f77000      C:\WINDOWS\System32\winrnr.dll
0x76f10000 - 0x76f3e000      C:\WINDOWS\system32\WLDAP32.dll
0x76f80000 - 0x76f85000      C:\WINDOWS\system32\rasadhlp.dll
0x4a6a0000 - 0x4a6ac000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\CustomerInfoProxy.dll
0x77670000 - 0x777a9000      C:\WINDOWS\system32\ole32.dll
0x77d00000 - 0x77d8b000      C:\WINDOWS\system32\OLEAUT32.dll
0x7c420000 - 0x7c4a7000      C:\WINDOWS\WinSxS\x86_Microsoft.VC80.CRT_1fc8b3b9a1e18e3b_8.0.50727.4053_x-ww_E6967989\MSVCP80.dll
0x78130000 - 0x781cb000      C:\WINDOWS\WinSxS\x86_Microsoft.VC80.CRT_1fc8b3b9a1e18e3b_8.0.50727.4053_x-ww_E6967989\MSVCR80.dll
0x777b0000 - 0x77833000      C:\WINDOWS\system32\CLBCatQ.DLL
0x77010000 - 0x770d6000      C:\WINDOWS\system32\COMRes.dll
0x77b90000 - 0x77b98000      C:\WINDOWS\system32\VERSION.dll
0x75da0000 - 0x75e5d000      C:\WINDOWS\system32\SXS.DLL
0x75e60000 - 0x75e87000      C:\WINDOWS\system32\apphelp.dll
0x4dc30000 - 0x4dc5e000      C:\WINDOWS\system32\msctfime.ime
0x4b0d0000 - 0x4b395000      C:\WINDOWS\system32\xpsp2res.dll
0x71bb0000 - 0x71bb9000      C:\WINDOWS\system32\WSOCK32.dll
0x4bbe0000 - 0x4bbea000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\ClearTranProxy.dll
0x745e0000 - 0x7489e000      C:\WINDOWS\system32\msi.dll
0x71c40000 - 0x71c97000      C:\WINDOWS\system32\NETAPI32.dll
0x4bc50000 - 0x4bc6c000      C:\WINDOWS\system32\DBNETLIB.DLL
0x71f60000 - 0x71f64000      C:\WINDOWS\system32\security.dll
0x76c90000 - 0x76cb7000      C:\WINDOWS\system32\msv1_0.dll
0x76cf0000 - 0x76d0a000      C:\WINDOWS\system32\iphlpapi.dll
0x761b0000 - 0x76243000      C:\WINDOWS\system32\crypt32.dll
0x76190000 - 0x761a2000      C:\WINDOWS\system32\MSASN1.dll
0x4bcf0000 - 0x4bcff000      C:\Program Files\Common Files\System\Ole DB\SQLOLEDB.RLL
0x4a8a0000 - 0x4a8aa000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\MIGI.DLL
0x73570000 - 0x736c2000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\MSVBVM60.DLL
0x4a950000 - 0x4a9e2000      C:\Program Files\Common Files\System\ado\msado15.dll
0x74a50000 - 0x74a6a000      C:\WINDOWS\system32\MSDART.DLL
0x4c850000 - 0x4c8c9000      C:\Program Files\Common Files\System\Ole DB\oledb32.dll
0x4dbb0000 - 0x4dbc1000      C:\Program Files\Common Files\System\Ole DB\OLEDB32R.DLL
VM Arguments:
jvm_args: -Dcatalina.home=C:\Program Files\Apache Software Foundation\Tomcat 5.5 -Dcatalina.base=C:\Program Files\Apache Software Foundation\Tomcat 5.5 -Djava.endorsed.dirs=C:\Program Files\Apache Software Foundation\Tomcat 5.5\common\endorsed -Djava.io.tmpdir=C:\Program Files\Apache Software Foundation\Tomcat 5.5\temp -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=C:\Program Files\Apache Software Foundation\Tomcat 5.5\conf\logging.properties -Djava.library.path=C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib vfprintf -Xms512m -Xmx1024m
java_command: <unknown>
Launcher Type: generic
Environment Variables:
JAVA_HOME=C:\Program Files\Java\jdk1.6.0_07
[error occurred during error reporting (printing environment variables), id 0xc0000005]
--------------- S Y S T E M ---------------
OS: Windows Server 2003 family Build 3790 Service Pack 2
CPU:total 4 (4 cores per cpu, 1 threads per core) family 6 model 7 stepping 6, cmov, cx8, fxsr, mmx, sse, sse2, sse3, ssse3
Memory: 4k page, physical 2097151k(2097151k free), swap 4194303k(4194303k free)
vm_info: Java HotSpot(TM) Client VM (10.0-b23) for windows-x86 JRE (1.6.0_07-b06), built on Jun 10 2008 01:14:11 by "java_re" with MS VC++ 7.1
time: Mon Dec 28 15:24:00 2009
elapsed time: 600 seconds