On Wed, 21 May 2025 13:24:32 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.
modules/javafx.graphics/src/main/java/com/sun/marlin/MaskMarlinAlphaConsumer.java
line 110:
> 108:
> 109: for (int i = 0; i < _ALPHA_MAP.length; i++) {
> 110: ALPHA_MAP_UNSAFE.putByte(i, _ALPHA_MAP[i]);
I know you are trying to keep the diffs to a minimum, but since there is no
more Unsafe, can we replace the "UNSAFE" with something more meaningful?
-------------
PR Review Comment: https://git.openjdk.org/jfx/pull/1814#discussion_r2100627122
