During the review of the Unsafe --> FFM conversion in JavaFX a few preexisting issues around range checking were noted. Specifically:

1. OffHeapArray uses a long for allocating the number of bytes and an int for "used" bytes. Consider whether to change used to be a long. If not, the additional range checking may be needed. Even leaving this aside, we should check both setUsed and incrementUsed to ensure that used <= length.

2. There is this TODO comment in Renderer.java and RendererAA.java:

            // suppose _edges.length > _SIZEOF_EDGE_BYTES
            // so doubling size is enough to add needed bytes
            // note: throw IOOB if neededSize > 2Gb:

As Andy noted, this is unclear - is this a TODO to throw IOOBE or a description of what would happen?