cufile tests: snapshot parameter baselines after driver_open

Open driver once to read size_t/bool/string originals, then close before
set/get/restore round-trips so pending does not restore invalid pre-open
values (e.g. per-buffer cache 0). Aligns with review feedback.

Author: rsarpangalav

cuda_bindings/tests/test_cufile.py

@@ -1394,8 +1394,16 @@ def test_set_get_parameter_size_t():
         (cufile.SizeTConfigParameter.EXECUTION_MAX_REQUEST_PARALLELISM, 4),  # Max 4 parallel requests
     )
 
+    # Snapshot baselines after driver_open so getters reflect merged config (defaults + JSON),
+    # not pre-open pending state that could restore invalid values (e.g. 0 for per-buffer cache).
+    cufile.driver_open()
+    try:
+        originals = {param: cufile.get_parameter_size_t(param) for param, _ in param_val_pairs}
+    finally:
+        cufile.driver_close()
+
     def test_param(param, val):
-        orig_val = cufile.get_parameter_size_t(param)
+        orig_val = originals[param]
         cufile.set_parameter_size_t(param, val)
         retrieved_val = cufile.get_parameter_size_t(param)
         assert retrieved_val == val
@@ -1436,8 +1444,14 @@ def test_set_get_parameter_bool():
     )
     param_val_pairs = tuple((p, v) for p, v in param_val_pairs if p not in _COMPAT_PARAMS)
 
+    cufile.driver_open()
+    try:
+        originals = {param: cufile.get_parameter_bool(param) for param, _ in param_val_pairs}
+    finally:
+        cufile.driver_close()
+
     def test_param(param, val):
-        orig_val = cufile.get_parameter_bool(param)
+        orig_val = originals[param]
         cufile.set_parameter_bool(param, val)
         retrieved_val = cufile.get_parameter_bool(param)
         assert retrieved_val is val
@@ -1477,8 +1491,14 @@ def test_set_get_parameter_string(tmp_path):
         ),  # Test log directory
     )
 
+    cufile.driver_open()
+    try:
+        originals = {param: cufile.get_parameter_string(param, 256) for param, _, _ in param_val_pairs}
+    finally:
+        cufile.driver_close()
+
     def test_param(param, val, default_val):
-        orig_val = cufile.get_parameter_string(param, 256)
+        orig_val = originals[param]
 
         val_b = val.encode("utf-8")
         val_buf = ctypes.create_string_buffer(val_b)