Lazy load code modules (#269)

Lazy load module in ObjectCode

Author: ksimpson-work

cuda_core/cuda/core/experimental/_module.py

@@ -5,7 +5,7 @@
 import importlib.metadata
 
 from cuda import cuda
-from cuda.core.experimental._utils import handle_return
+from cuda.core.experimental._utils import handle_return, precondition
 
 _backend = {
     "old": {
@@ -106,30 +106,43 @@ class ObjectCode:
 
     """
 
-    __slots__ = ("_handle", "_code_type", "_module", "_loader", "_sym_map")
+    __slots__ = ("_handle", "_backend_version", "_jit_options", "_code_type", "_module", "_loader", "_sym_map")
     _supported_code_type = ("cubin", "ptx", "ltoir", "fatbin")
 
     def __init__(self, module, code_type, jit_options=None, *, symbol_mapping=None):
         if code_type not in self._supported_code_type:
             raise ValueError
         _lazy_init()
+
+        # handle is assigned during _lazy_load
         self._handle = None
+        self._jit_options = jit_options
+
+        self._backend_version = "new" if (_py_major_ver >= 12 and _driver_ver >= 12000) else "old"
+        self._loader = _backend[self._backend_version]
+
+        self._code_type = code_type
+        self._module = module
+        self._sym_map = {} if symbol_mapping is None else symbol_mapping
 
-        backend = "new" if (_py_major_ver >= 12 and _driver_ver >= 12000) else "old"
-        self._loader = _backend[backend]
+    # TODO: do we want to unload in a finalizer? Probably not..
 
+    def _lazy_load_module(self, *args, **kwargs):
+        if self._handle is not None:
+            return
+        jit_options = self._jit_options
+        module = self._module
         if isinstance(module, str):
             # TODO: this option is only taken by the new library APIs, but we have
             # a bug that we can't easily support it just yet (NVIDIA/cuda-python#73).
             if jit_options is not None:
                 raise ValueError
-            module = module.encode()
             self._handle = handle_return(self._loader["file"](module))
         else:
             assert isinstance(module, bytes)
             if jit_options is None:
                 jit_options = {}
-            if backend == "new":
+            if self._backend_version == "new":
                 args = (
                     module,
                     list(jit_options.keys()),
@@ -141,15 +154,15 @@ def __init__(self, module, code_type, jit_options=None, *, symbol_mapping=None):
                     0,
                 )
             else:  # "old" backend
-                args = (module, len(jit_options), list(jit_options.keys()), list(jit_options.values()))
+                args = (
+                    module,
+                    len(jit_options),
+                    list(jit_options.keys()),
+                    list(jit_options.values()),
+                )
             self._handle = handle_return(self._loader["data"](*args))
 
-        self._code_type = code_type
-        self._module = module
-        self._sym_map = {} if symbol_mapping is None else symbol_mapping
-
-    # TODO: do we want to unload in a finalizer? Probably not..
-
+    @precondition(_lazy_load_module)
     def get_kernel(self, name):
         """Return the :obj:`Kernel` of a specified name from this object code.
 
@@ -168,6 +181,7 @@ def get_kernel(self, name):
             name = self._sym_map[name]
         except KeyError:
             name = name.encode()
+
         data = handle_return(self._loader["kernel"](self._handle, name))
         return Kernel._from_obj(data, self)
 

cuda_core/tests/conftest.py

@@ -11,10 +11,10 @@
 import sys
 
 try:
-    from cuda.bindings import driver
+    from cuda.bindings import driver, nvrtc
 except ImportError:
     from cuda import cuda as driver
-
+    from cuda import nvrtc
 import pytest
 
 from cuda.core.experimental import Device, _device
@@ -65,3 +65,9 @@ def clean_up_cffi_files():
             os.remove(f)
         except FileNotFoundError:
             pass  # noqa: SIM105
+
+
+def can_load_generated_ptx():
+    _, driver_ver = driver.cuDriverGetVersion()
+    _, nvrtc_major, nvrtc_minor = nvrtc.nvrtcVersion()
+    return nvrtc_major * 1000 + nvrtc_minor * 10 <= driver_ver

cuda_core/tests/test_module.py

@@ -6,43 +6,22 @@
 # this software and related documentation outside the terms of the EULA
 # is strictly prohibited.
 
-import importlib
 
 import pytest
-
-from cuda.core.experimental._module import ObjectCode
-
-
-@pytest.mark.skipif(
-    int(importlib.metadata.version("cuda-python").split(".")[0]) < 12,
-    reason="Module loading for older drivers validate require valid module code.",
-)
-def test_object_code_initialization():
-    # Test with supported code types
-    for code_type in ["cubin", "ptx", "fatbin"]:
-        module_data = b"dummy_data"
-        obj_code = ObjectCode(module_data, code_type)
-        assert obj_code._code_type == code_type
-        assert obj_code._module == module_data
-        assert obj_code._handle is not None
-
-    # Test with unsupported code type
-    with pytest.raises(ValueError):
-        ObjectCode(b"dummy_data", "unsupported_code_type")
-
-
-# TODO add ObjectCode tests which provide the appropriate data for cuLibraryLoadFromFile
-def test_object_code_initialization_with_str():
-    assert True
-
-
-def test_object_code_initialization_with_jit_options():
-    assert True
-
-
-def test_object_code_get_kernel():
-    assert True
-
-
-def test_kernel_from_obj():
-    assert True
+from conftest import can_load_generated_ptx
+
+from cuda.core.experimental import Program
+
+
+@pytest.mark.xfail(not can_load_generated_ptx(), reason="PTX version too new")
+def test_get_kernel():
+    kernel = """
+extern __device__ int B();
+extern __device__ int C(int a, int b);
+__global__ void A() { int result = C(B(), 1);}
+"""
+    object_code = Program(kernel, "c++").compile("ptx", options=("-rdc=true",))
+    assert object_code._handle is None
+    kernel = object_code.get_kernel("A")
+    assert object_code._handle is not None
+    assert kernel._handle is not None

cuda_core/tests/test_program.py

@@ -7,20 +7,12 @@
 # is strictly prohibited.
 
 import pytest
+from conftest import can_load_generated_ptx
 
-from cuda import cuda, nvrtc
 from cuda.core.experimental import Device, Program
 from cuda.core.experimental._module import Kernel, ObjectCode
 
 
-def can_load_generated_ptx():
-    _, driver_ver = cuda.cuDriverGetVersion()
-    _, nvrtc_major, nvrtc_minor = nvrtc.nvrtcVersion()
-    if nvrtc_major * 1000 + nvrtc_minor * 10 > driver_ver:
-        return False
-    return True
-
-
 def test_program_init_valid_code_type():
     code = 'extern "C" __global__ void my_kernel() {}'
     program = Program(code, "c++")