On Tue, 10 Jun 2025 15:31:22 GMT, Kevin Rushforth <k...@openjdk.org> wrote:
>> PR to replace the use of sun.misc.Unsafe memory access methods in the Marlin >> rasterizer with FFM. >> >> I broke this up into the following commits. The bulk of the work is in the >> first two: >> >> 1. Encapsulate all off-heap access in OffHeapArray -- All of the memory >> allocation and management was already done in the OffHeapArray class, but >> the users of OffHeapArray, primarily Renderer and RendererNoAA, called >> Unsafe methods directly. I encapsulated all of the calls to Unsafe in >> OffHeapArray. The main impact on calling code is that the base address is no >> longer accessible or needed. Instead, the `(put|get)(Byte|Int)` methods take >> only an offset. This commit was straight refactoring with no behavioral >> changes. >> 2. Initial FFM implementation -- I changed the memory management and access >> methods to use FFM. Each OffHeap array uses a shared Arena to manage the >> single memory segment allocated at construction time. The resize method >> creates a new Arena and memory segment, copying the data from the old and >> then closing it >> 3. Set `used` to 0 in `dispose()` -- While testing and instrumenting the >> code, I discovered that the Renderer dispose methods resize the edges array >> back to the default size without clearing the "used" field. The used field >> will be cleared before the next time it is accessed, but clearing it in >> dispose allows optimizing resize to not copy any data. >> 4. Remove '--sun-misc-unsafe-memory-access=allow' from test and app >> execution, since it is no longer needed. This also enables `-Werror` for the >> `javafx.graphics` module. >> 5. ~~Temporary debug prints that will be removed before making this "rfr"~~ >> >> Additional commits address review comments. > > Kevin Rushforth has updated the pull request incrementally with one > additional commit since the last revision: > > Initialize alpha maps in constructor to ensure they are created on the > right thread (QuantumRenderer) I was going to file a follow-on issue for switching to the global arena for the alpha maps, but I now think it is better to do that now. The changes are simple. My initial testing shows that it works quite well. I'll make the change in this PR shortly, after some further testing. ------------- PR Comment: https://git.openjdk.org/jfx/pull/1814#issuecomment-2962688219
