From 96bc209baf55f2e05e649e555c2de5fc478c24dc Mon Sep 17 00:00:00 2001
From: Titus von Koeller <titus@vonkoeller.com>
Date: Tue, 2 Aug 2022 21:27:36 -0700
Subject: [PATCH] tentative refactoring of the compute capabilities code

---
 bitsandbytes/cuda_setup/compute_capability.py | 56 ++++++++++++-------
 1 file changed, 35 insertions(+), 21 deletions(-)

diff --git a/bitsandbytes/cuda_setup/compute_capability.py b/bitsandbytes/cuda_setup/compute_capability.py
index 19ceb3b..7a3f463 100644
--- a/bitsandbytes/cuda_setup/compute_capability.py
+++ b/bitsandbytes/cuda_setup/compute_capability.py
@@ -2,27 +2,28 @@ import ctypes
 from dataclasses import dataclass, field
 
 
-CUDA_SUCCESS = 0
-
 @dataclass
 class CudaLibVals:
-    # code bits taken from 
+    # code bits taken from
     # https://gist.github.com/f0k/63a664160d016a491b2cbea15913d549
 
-    nGpus = ctypes.c_int()
-    cc_major = ctypes.c_int()
-    cc_minor = ctypes.c_int()
-    device = ctypes.c_int()
-    error_str = ctypes.c_char_p()
+    nGpus: ctypes.c_int = field(default=ctypes.c_int())
+    cc_major: ctypes.c_int = field(default=ctypes.c_int())
+    cc_minor: ctypes.c_int = field(default=ctypes.c_int())
+    device: ctypes.c_int = field(default=ctypes.c_int())
+    error_str: ctypes.c_char_p = field(default=ctypes.c_char_p())
     cuda: ctypes.CDLL = field(init=False, repr=False)
     ccs: List[str, ...] = field(init=False)
 
-    def load_cuda_lib(self):
+    def _initialize_driver_API(self):
+        self.check_cuda_result(self.cuda.cuInit(0))
+
+    def _load_cuda_lib(self):
         """
         1. find libcuda.so library (GPU driver) (/usr/lib)
            init_device -> init variables -> call function by reference
         """
-        libnames = ("libcuda.so")
+        libnames = "libcuda.so"
         for libname in libnames:
             try:
                 self.cuda = ctypes.CDLL(libname)
@@ -33,32 +34,45 @@ class CudaLibVals:
         else:
             raise OSError("could not load any of: " + " ".join(libnames))
 
-    def check_cuda_result(self, result_val):
+    def call_cuda_func(self, function_obj, **kwargs):
+        CUDA_SUCCESS = 0  # constant taken from cuda.h
+        pass
+        # if (CUDA_SUCCESS := function_obj(
+
+    def _error_handle(cuda_lib_call_return_value):
         """
-        2. call extern C function to determine CC 
+        2. call extern C function to determine CC
            (see https://docs.nvidia.com/cuda/cuda-driver-api/group__CUDA__DEVICE__DEPRECATED.html)
         """
-        cls_fields: Tuple[Field, ...] = fields(self.__class__)
+        CUDA_SUCCESS = 0  # constant taken from cuda.h
 
-        if result_val != 0:
-            self.cuda.cuGetErrorString(result_val, ctypes.byref(self.error_str))
+        if cuda_lib_call_return_value != CUDA_SUCCESS:
+            self.cuda.cuGetErrorString(
+                cuda_lib_call_return_value,
+                ctypes.byref(self.error_str),
+            )
             print("Count not initialize CUDA - failure!")
             raise Exception("CUDA exception!")
-        return result_val
+        return cuda_lib_call_return_value
 
     def __post_init__(self):
-        self.load_cuda_lib()
-        self.check_cuda_result(self.cuda.cuInit(0))
-        self.check_cuda_result(self.cuda, self.cuda.cuDeviceGetCount(ctypes.byref(self.nGpus)))
+        self._load_cuda_lib()
+        self._initialize_driver_API()
+        self.check_cuda_result(
+            self.cuda, self.cuda.cuDeviceGetCount(ctypes.byref(self.nGpus))
+        )
         tmp_ccs = []
         for gpu_index in range(self.nGpus.value):
             check_cuda_result(
-                self.cuda, self.cuda.cuDeviceGet(ctypes.byref(self.device), gpu_index)
+                self.cuda,
+                self.cuda.cuDeviceGet(ctypes.byref(self.device), gpu_index),
             )
             check_cuda_result(
                 self.cuda,
                 self.cuda.cuDeviceComputeCapability(
-                    ctypes.byref(self.cc_major), ctypes.byref(self.cc_minor), self.device
+                    ctypes.byref(self.cc_major),
+                    ctypes.byref(self.cc_minor),
+                    self.device,
                 ),
             )
             tmp_ccs.append(f"{self.cc_major.value}.{self.cc_minor.value}")