Matlab crashes on library initialize when called from Java

Question

Hello everyone. The setup I have is I'm using a Java application to call native C-code with JNI, which in turn starts up the MATLAB runtime and calls functions on it (I know there are other solutions to call MATLAB methods from Java).

The problem is that the MATLAB engine crashes at some point during the initialization and I don't know what's causing it exactly. The crash causes my jvm to terminate, I assume it's some kind of memory corruption.

The C++ code calling MATLAB functions that is actually crashing is

JNIEXPORT void JNICALL 
some_jni_vodoo_initializeLibrary(JNIEnv* env, jclass thisClass) {
  try {
      if (!mclInitializeApplication(NULL, 0)) {
          THROW_EXCEPTION(env, "Could not initialize the application properly.");
          return;
      }
      if (!<library>Initialize()) {
          THROW_EXCEPTION(env, "Could not initialize the library.");
          return;
      }
    } ...

The function <library>Initialize() crashes here, the Java error log reads

Stack Trace:
  [0] jmi.dll:0x793f4175(0x7934cdca, 1, 0x7937e67c "à;.y`[email protected] in C:\BUILD_ARE..", 0x792d6a32)
  [1] jvm.dll:0x792df9a5(0xc0000005, 0x79356791, 0x4961b400 "Ð\8y", 0x6d8b29de)
  [2] jvm.dll:0x792e0431(0x8b515008, 0x70f0e8ce, 0x8b5ffffa, 0xc25d5ec6)

------------------------------------------------------------------------
        Fatal Java Exception detected at Fri Apr 30 11:08:08 2010
------------------------------------------------------------------------

Configuration:
  MATLAB Version:   7.8.0.347 (R2009a)
  MATLAB License:   unknown
  Operating System: Microsoft Windows Vista
  Window System:    Version 6.0 (Build 6002: Service Pack 2)
  Processor ID:     x86 Family 6 Model 10 Stepping 5, GenuineIntel
  Virtual Machine:  Java is not enabled
  Default Encoding:  windows-1252

Java is not enabled

I really have no idea what could be wrong. Is there not enough memory from the jvm? I guess the problem is somehow related to Java, since calling the JNI functions from a simple test C++ program works fine...

Thanks

Answer 1

The only similar thing I've ever seen is a silent exit from MATLAB due to an invalid license.

Another possibility is the nested Java environments. Since MATLAB expects its own Java environment, perhaps there is some problem here.

Are you running the MATLAB Engine? Or are you calling separate MATLAB commands using some "system" or "exec" call? This might give a good clue.

---

Edit:
The answer appears below in the comments. When nesting an invocation of MATLAB's engine in a process that has its own JVM, you must either tell MATLAB to run without a JVM by passing -nojvm to the mclInitializeApplication or tell it which JMN to use by setting the global MATLAB_JAVA to the location of the JVM you wish to use, C:\Program Files\Java\jre6 for example.

The first option will disable any functionality in MATLAB that requires the JVM, so the second option is preferable.