Executors

An executor owns what a call runs on but a model does not: host threads or device streams, activation scratch, and the pinned buffer staging passes through.

• uform_executor_for_ram creates an executor of host threads across the compute domains local to the memory domains of its uform_ram_options_t, 7/8 of their cores when threads is zero.
• uform_executor_on_pool lends UForm a ForkUnion fu_pool_t another library spawned, so UForm, USearch and UStore in one process share one set of threads; the pool must outlive the executor.
• uform_executor_for_vram opens one stream on every device of its uform_vram_options_t, named by their position in uform_gpu_devices, beside host threads for the decoding the devices cannot do.
• uform_executor_drain waits until no call holds the executor, then applies the uform_mood_t its threads keep until the next call: parked sleeps in the kernel, spinning keeps polling.
• uform_executor_free waits the same way, releases what the executor owns and returns what it borrowed.

One executor serves any number of models of its residency, and a call pairing a model with an executor of another residency reports uform_status_device_k. A NULL executor runs the call on the calling thread, final when it returns. cpu_class and gpu_class in the options pin the class a call dispatches as, and uform_status_unsupported_k answers a class the machine cannot run.

§ Classes and Devices

Dispatch picks one tuned variant per CPU or GPU family, named by uform_cpu_class_t and uform_gpu_class_t, whose enumerators and ordinals are USearch’s. uform_ram_options_t::cpu_class and uform_vram_options_t::gpu_class pin one, and the unknown zero derives the hardware’s own:

• A CPU pin dispatches as if the CPU were of that class, taking every rung whose features it holds, and a class the CPU cannot run reports uform_status_unsupported_k.
• A GPU pin dispatches every named device as that class, and a device that cannot run it reports uform_status_unsupported_k.
• Unpinned devices of one VRAM executor must share a class, or the call reports uform_status_config_mismatch_k.

uform_gpu_devices lists every GPU the process can drive, NVIDIA devices first, then AMD, each as a uform_gpu_device_t of its vendor, vendor ordinal, class, compute units, memory and name. A device’s position in that listing is the ordinal uform_vram_options_t::devices names it by, and a machine without GPUs lists none and succeeds. uform_cpu_class_name and uform_gpu_class_name spell a class, like intel-haswell or nvidia-hopper, and the _from_name verbs read one back.