I have a java object which calls into a C++ shared object via JNI. In C++, I am saving a reference to the JNIEnv and jObject.

JavaVM * jvm;
JNIEnv * myEnv;
jobject myobj;

JNIEXPORT void JNICALL Java_org_api_init
   (JNIEnv *env, jobject jObj) {
    myEnv = env;
    myobj = jObj;
}

I also have a GLSurface renderer and it eventually calls the C++ shared object mentioned above on a different thread, the GLThread. I am then trying to call back into my original Java object using the jobject I saved initially, but I think because I am on the GLThread, I get the following error.

W/dalvikvm(16101): JNI WARNING: 0x41ded218 is not a valid JNI reference
I/dalvikvm(16101): "GLThread 981" prio=5 tid=15 RUNNABLE
I/dalvikvm(16101):   | group="main" sCount=0 dsCount=0 obj=0x41d6e220 self=0x5cb11078
I/dalvikvm(16101):   | sysTid=16133 nice=0 sched=0/0 cgrp=apps handle=1555429136
I/dalvikvm(16101):   | schedstat=( 0 0 0 ) utm=42 stm=32 core=1

The code calling back into Java :

void setData()
    {
        jvm->AttachCurrentThread(&myEnv, 0);

        jclass javaClass = myEnv->FindClass("com/myapp/myClass");
        if(javaClass == NULL){
            LOGD("ERROR - cant find class");
        }

        jmethodID method = myEnv->GetMethodID(javaClass, "updateDataModel", "()V");
        if(method == NULL){
            LOGD("ERROR - cant access method");
        }

        // this works, but its a new java object
        //jobject myobj2 = myEnv->NewObject(javaClass, method);

        //this is where the crash occurs
        myEnv->CallVoidMethod(myobj, method, NULL); 

}

If instead I create a new jObject using env->NewObject, I can succuessfully call back into Java, but it is a new object and I dont want that. I need to get back to my original Java Object.

Is it a matter of switching threads before I call back into Java? If so, how do I do so ?