Invoker cache created and written to even when PYOPENCL_NO_CACHE=1

[hvenev-insait]

When PYOPENCL_NO_CACHE=1, the invoker cache is always created when importing pyopencl.invoker. Furthermore, it is written to every time an invoker is created. PYOPENCL_NO_CACHE only seems to control reads.

To Reproduce
Steps to reproduce the behavior:

1. Delete all caches.
2. Run python3 with the PYOPENCL_NO_CACHE environment variable set to 1.
3. Import pyopencl and run a kernel.
4. Observe that the invoker cache now exists.

Expected behavior
When PYOPENCL_NO_CACHE=1, no attempts should be made to read caches, write caches, create caches, lock caches, or check whether caches exist.

Environment:

• OS: Linux
• ICD Loader and version: ocl-icd 2.3.2
• ICD and version: pocl 6.0, NVIDIA 550.90.07
• x86-64, NVIDIA A6000
• Python version: 3.12.4
• PyOpenCL version: 2024.1

[matthiasdiener]

This should be fixed in 2024.2, see e.g. #736.

[hvenev-insait]

Yes, it looks like that fixes it.