My native code successfully executes the Java JniCallback method, and receives the resulting returned data. The location of the exception is the value of the number parameter being passed to the callback method. What is wrong? It does appear that the input value of number is being used as a pointer, but when I try to pass a pointer to number instead of the value, there is no improvement. Thanks in advance.
Here is the JniWrapperShim class code:
private Library _kernel;
public JniWrapperShim(){
// add the relative path to the .dll file here
DefaultLibraryLoader.getInstance().addPath("C:
JNIWrapper
bin");
kernel = new Library("TestJNIWrapper", Function.CDECLCALLING_CONVENTION);
}
public long TestCallback( ) {
JniCallback myCallback = new JniCallback();
int number = 1;
Int sum = new Int();
Function testNativeCallback = _kernel.getFunction("nativeCallback");
testNativeCallback.invoke(sum, new Parameter[]
{
myCallback,
new Int(number)
});
myCallback.dispose();
return sum.getValue();
}
The native TestJniWrapper code:
typedef int (*Callback) (int);
int sum = 0;
__declspec(dllexport) int nativeCallback(Callback func, int number)
{
cout << "value of sum = " << sum << endl;
cout << "value of number before callback = " << number << endl;
sum = func(number);
cout << "value of sum after callback = " << sum << endl;
return sum;
}
The Java JniCallback class:
public class JniCallback extends Callback {
private Int argument = new Int();
private Int res = new Int();
public JniCallback(){
init(new Parameter[]{argument}, res);
}
public void callback() {
res.setValue(argument.getValue()+1);
}
}
The console shows the following:
value of sum = 0
value of number before callback = 1
value of sum after callback = 2
Exception c0000005, at 00000001
Access violation: attempting to read memory at address 00000001
Native function stack data: 0,858e00,1,2e0072,6c0064,6c,21,a1,4,ffffffff,858c6c,858c7c
