ClassCastException in Unsafe buffer wrapping a HeapByteBufferR

[robertroeser]

Hi,

I'm getting a class cast exception using an UnsafeBuffer. Looks like HeapByteBufferR doesn't implement DirectBuffer and is causing problems. Here's the pertinent stack trace fragments:

java.lang.ClassCastException: java.nio.HeapByteBufferR cannot be cast to sun.nio.ch.DirectBuffer
    at org.agrona.concurrent.UnsafeBuffer.putBytes(UnsafeBuffer.java:891)
    at org.agrona.concurrent.UnsafeBuffer.putBytes(UnsafeBuffer.java:869)

Thanks,
Robert

[mjpt777]

What JDK and by what means have you created the ByteBuffer?

[mjpt777]

Also what version of Agrona are you using?

[mikeb01]

The problem is that the buffer that is been passed to UnsafeBuffer is a readonly one. HeapByteBufferR will return false when calling hasArray() despite being heap allocated. The wrap call uses this to determine if this should be treated as a heap or direct buffer.

[mjpt777]

@mikeb01 I just noticed this. Seems ready-only heap buffers give the wrong answers to hasArray() and throw and exception on array().

[mjpt777]

This should now be consistent across direct and heap buffers.