JNI global reference in native code

[etiainen]

Hello everyone, I have a question:
is there a way to make a global reference (pointer) in native code that'll survive between native method invocations?

something like this:

...
Some_struct *something=NULL;

JNIEXPORT void JNICALL Java_SomeClass_initSomething(JNIEnv *env, jobject obj);

JNIEXPORT jint JNICALL Java_SomeClass_useSomething(JNIEnv *env, jobject obj);
...

[JosAH]

Does this help?

kind regards,

Jos

[etiainen]

Well, it does a little bit...
The thing is that I don't have a matching java type for the structure of the native variable. I don't know if GlobalRef can refer to something completely native without knowing about its structure. But here's a bright idea, I'll try holding that reference as void* and casting it in native calls...

Thanks Jos!

[JosAH]

Well, it does a little bit...
The thing is that I don't have a matching java type for the structure of the native variable. I don't know if GlobalRef can refer to something completely native without knowing about its structure. But here's a bright idea, I'll try holding that reference as void* and casting it in native calls...

Thanks Jos!

It's even simpler; I read a bit more and found this; it basically means that the JVM
leaves your allocated structs alone. All you need to do is keep a pointer to it
somewhere; you can keep this pointer yourself in a global variable or you can make
the JVM keep it (in an int or long in which case you have to cast the value).

kind regards,

Jos