[DLPACK] Enable cython support

include/tvm/runtime/c_runtime_api.h

@@ -467,7 +467,7 @@ TVM_DLL int TVMArrayToDLPack(TVMArrayHandle from,
 
 /*!
  * \brief Delete (free) a DLManagedTensor's data.
- * \param dltensor Pointer to the DLManagedTensor. 
+ * \param dltensor Pointer to the DLManagedTensor.
  */
 TVM_DLL void TVMDLManagedTensorCallDeleter(DLManagedTensor* dltensor);
 

python/tvm/_ffi/_ctypes/ndarray.py

@@ -1,11 +1,47 @@
+# pylint: disable=invalid-name
 """Runtime NDArray api"""
 from __future__ import absolute_import
 
 import ctypes
-from ..base import _LIB, check_call
+from ..base import _LIB, check_call, c_str
 from ..runtime_ctypes import TVMArrayHandle
 from .types import RETURN_SWITCH, C_TO_PY_ARG_SWITCH, _wrap_arg_func, _return_handle
 
+
+TVMPyCapsuleDestructor = ctypes.CFUNCTYPE(None, ctypes.c_void_p)
+_c_str_dltensor = c_str('dltensor')
+_c_str_used_dltensor = c_str('used_dltensor')
+
+
+# used for PyCapsule manipulation
+if hasattr(ctypes, 'pythonapi'):
+    ctypes.pythonapi.PyCapsule_GetName.restype = ctypes.c_char_p
+    ctypes.pythonapi.PyCapsule_GetPointer.restype = ctypes.c_void_p
+    ctypes.pythonapi.PyCapsule_New.restype = ctypes.py_object
+
+
+def _from_dlpack(dltensor):
+    dltensor = ctypes.py_object(dltensor)
+    if ctypes.pythonapi.PyCapsule_IsValid(dltensor, _c_str_dltensor):
+        ptr = ctypes.pythonapi.PyCapsule_GetPointer(dltensor, _c_str_dltensor)
+        handle = TVMArrayHandle()
+        check_call(_LIB.TVMArrayFromDLPack(ptr, ctypes.byref(handle)))
+        ctypes.pythonapi.PyCapsule_SetName(dltensor, _c_str_used_dltensor)
+        ctypes.pythonapi.PyCapsule_SetDestructor(dltensor, TVMPyCapsuleDestructor(0))
+        return _make_array(handle, False)
+    raise ValueError("Expect a dltensor field, PyCapsule can only be consumed once")
+
+
+def _dlpack_deleter(pycapsule):
+    pycapsule = ctypes.cast(pycapsule, ctypes.py_object)
+    if ctypes.pythonapi.PyCapsule_IsValid(pycapsule, _c_str_dltensor):
+        ptr = ctypes.pythonapi.PyCapsule_GetPointer(pycapsule, _c_str_dltensor)
+        _LIB.TVMDLManagedTensorCallDeleter(ptr)
+        ctypes.pythonapi.PyCapsule_SetDestructor(dltensor, TVMPyCapsuleDestructor(0))
+
+_c_dlpack_deleter = TVMPyCapsuleDestructor(_dlpack_deleter)
+
+
 class NDArrayBase(object):
     """A simple Device/CPU Array object in runtime."""
     __slots__ = ["handle", "is_view"]
@@ -29,6 +65,17 @@ def __del__(self):
     def _tvm_handle(self):
         return ctypes.cast(self.handle, ctypes.c_void_p).value
 
+    def to_dlpack(self):
+        """Produce an array from a DLPack Tensor without copying memory
+
+        Returns
+        -------
+        dlpack : DLPack tensor view of the array data
+        """
+        handle = ctypes.c_void_p()
+        check_call(_LIB.TVMArrayToDLPack(self.handle, ctypes.byref(handle)))
+        return ctypes.pythonapi.PyCapsule_New(handle, _c_str_dltensor, _c_dlpack_deleter)
+
 
 def _make_array(handle, is_view):
     handle = ctypes.cast(handle, TVMArrayHandle)

python/tvm/_ffi/_cython/base.pxi

@@ -1,6 +1,7 @@
 from ..base import TVMError
 from libcpp.vector cimport vector
 from cpython.version cimport PY_MAJOR_VERSION
+from cpython cimport pycapsule
 from libc.stdint cimport int64_t, uint64_t, uint8_t, uint16_t
 import ctypes
 
@@ -40,6 +41,11 @@ cdef extern from "tvm/runtime/c_runtime_api.h":
         int64_t* strides
         uint64_t byte_offset
 
+    ctypedef struct DLManagedTensor:
+        DLTensor dl_tensor
+        void* manager_ctx
+        void (*deleter)(DLManagedTensor* self)
+
     ctypedef struct TVMValue:
         int64_t v_int64
         double v_float64
@@ -49,7 +55,7 @@ cdef extern from "tvm/runtime/c_runtime_api.h":
         DLContext v_ctx
 
 ctypedef int64_t tvm_index_t
-ctypedef void* DLTensorHandle
+ctypedef DLTensor* DLTensorHandle
 ctypedef void* TVMStreamHandle
 ctypedef void* TVMRetValueHandle
 ctypedef void* TVMFunctionHandle
@@ -92,6 +98,11 @@ cdef extern from "tvm/runtime/c_runtime_api.h":
     int TVMArrayCopyFromTo(DLTensorHandle src,
                            DLTensorHandle to,
                            TVMStreamHandle stream)
+    int TVMArrayFromDLPack(DLManagedTensor* arr_from,
+                           DLTensorHandle* out)
+    int TVMArrayToDLPack(DLTensorHandle arr_from,
+                         DLManagedTensor** out)
+    void TVMDLManagedTensorCallDeleter(DLManagedTensor* dltensor)
 
 cdef extern from "tvm/c_dsl_api.h":
     int TVMNodeFree(NodeHandle handle)

python/tvm/_ffi/_cython/ndarray.pxi

@@ -1,5 +1,29 @@
 from ..runtime_ctypes import TVMArrayHandle
 
+cdef const char* _c_str_dltensor = "dltensor"
+cdef const char* _c_str_used_dltensor = "used_dltensor"
+
+
+cdef void _c_dlpack_deleter(object pycaps):
+    cdef DLManagedTensor* dltensor
+    if pycapsule.PyCapsule_IsValid(pycaps, _c_str_dltensor):
+        dltensor = <DLManagedTensor*>pycapsule.PyCapsule_GetPointer(pycaps, _c_str_dltensor)
+        TVMDLManagedTensorCallDeleter(dltensor)
+
+
+def _from_dlpack(object dltensor):
+    cdef DLManagedTensor* ptr
+    cdef DLTensorHandle chandle
+    if pycapsule.PyCapsule_IsValid(dltensor, _c_str_dltensor):
+        ptr = <DLManagedTensor*>pycapsule.PyCapsule_GetPointer(dltensor, _c_str_dltensor)
+        CALL(TVMArrayFromDLPack(ptr, &chandle))
+        # set name and destructor to be empty
+        pycapsule.PyCapsule_SetDestructor(dltensor, NULL)
+        pycapsule.PyCapsule_SetName(dltensor, _c_str_used_dltensor)
+        return c_make_array(chandle, 0)
+    raise ValueError("Expect a dltensor field, pycapsule.PyCapsule can only be consumed once")
+
+
 cdef class NDArrayBase:
     cdef DLTensor* chandle
     cdef int c_is_view
@@ -35,12 +59,26 @@ cdef class NDArrayBase:
         if self.c_is_view == 0:
             CALL(TVMArrayFree(self.chandle))
 
+    def to_dlpack(self):
+        """Produce an array from a DLPack Tensor without copying memory
+
+        Returns
+        -------
+        dlpack : DLPack tensor view of the array data
+        """
+        cdef DLManagedTensor* dltensor
+        if self.c_is_view != 0:
+            raise ValueError("to_dlpack do not work with memory views")
+        CALL(TVMArrayToDLPack(self.chandle, &dltensor))
+        return pycapsule.PyCapsule_New(dltensor, _c_str_dltensor, _c_dlpack_deleter)
+
 
 cdef c_make_array(void* chandle, is_view):
     ret = _CLASS_NDARRAY(None, is_view)
     (<NDArrayBase>ret).chandle = <DLTensor*>chandle
     return ret
 
+
 cdef _TVM_COMPATS = ()
 
 cdef _TVM_EXT_RET = {}

python/tvm/_ffi/ndarray.py

@@ -17,28 +17,17 @@
     if _FFI_MODE == "ctypes":
         raise ImportError()
     if sys.version_info >= (3, 0):
-        from ._cy3.core import _set_class_ndarray, _reg_extension, _make_array
+        from ._cy3.core import _set_class_ndarray, _reg_extension, _make_array, _from_dlpack
         from ._cy3.core import NDArrayBase as _NDArrayBase
     else:
-        from ._cy2.core import _set_class_ndarray, _reg_extension, _make_array
+        from ._cy2.core import _set_class_ndarray, _reg_extension, _make_array, _from_dlpack
         from ._cy2.core import NDArrayBase as _NDArrayBase
 except IMPORT_EXCEPT:
     # pylint: disable=wrong-import-position
-    from ._ctypes.ndarray import _set_class_ndarray, _reg_extension, _make_array
+    from ._ctypes.ndarray import _set_class_ndarray, _reg_extension, _make_array, _from_dlpack
     from ._ctypes.ndarray import NDArrayBase as _NDArrayBase
 
 
-TVMPyCapsuleDestructor = ctypes.CFUNCTYPE(None, ctypes.c_void_p)
-_c_str_dltensor = c_str('dltensor')
-
-
-# used for PyCapsule manipulation
-if hasattr(ctypes, 'pythonapi'):
-    ctypes.pythonapi.PyCapsule_GetName.restype = ctypes.c_char_p
-    ctypes.pythonapi.PyCapsule_GetPointer.restype = ctypes.c_void_p
-    ctypes.pythonapi.PyCapsule_New.restype = ctypes.py_object
-
-
 def context(dev_type, dev_id=0):
     """Construct a TVM context with given device type and id.
 
@@ -134,30 +123,14 @@ def from_dlpack(dltensor):
     Parameters
     ----------
     dltensor : DLPack tensor
+        Input DLManagedTensor, can only be consumed once.
 
     Returns
     -------
     arr: tvm.nd.NDArray
         The array view of the tensor data.
     """
-    dltensor = ctypes.py_object(dltensor)
-    name = ctypes.pythonapi.PyCapsule_GetName(dltensor)
-    ptr = ctypes.pythonapi.PyCapsule_GetPointer(dltensor, name)
-    handle = TVMArrayHandle()
-    check_call(_LIB.TVMArrayFromDLPack(ptr, ctypes.byref(handle)))
-    ctypes.pythonapi.PyCapsule_SetDestructor(dltensor, None)
-    return _make_array(handle, False)
-
-
-def _dlpack_deleter(pycapsule):
-    pycapsule = ctypes.py_object(pycapsule)
-    if ctypes.pythonapi.PyCapsule_IsValid(pycapsule, _c_str_dltensor):
-        ptr = ctypes.pythonapi.PyCapsule_GetPointer(pycapsule, _c_str_dltensor)
-        _LIB.TVMDLManagedTensorCallDeleter(ptr)
-        ctypes.pythonapi.PyCapsule_SetDestructor(dltensor, TVMPyCapsuleDestructor(0))
-
-
-_c_dlpack_deleter = TVMPyCapsuleDestructor(_dlpack_deleter)
+    return _from_dlpack(dltensor)
 
 
 class NDArrayBase(_NDArrayBase):
@@ -308,17 +281,6 @@ def copyto(self, target):
             raise ValueError("Unsupported target type %s" % str(type(target)))
         return target
 
-    def to_dlpack(self):
-        """Produce an array from a DLPack Tensor without copying memory
-
-        Returns
-        -------
-        dlpack : DLPack tensor view of the array data
-        """
-        handle = ctypes.c_void_p()
-        check_call(_LIB.TVMArrayToDLPack(self.handle, ctypes.byref(handle)))
-        return ctypes.pythonapi.PyCapsule_New(handle, _c_str_dltensor, _c_dlpack_deleter)
-
 
 def free_extension_handle(handle, type_code):
     """Free c++ extension type handle

tests/scripts/task_python_nnvm.sh

@@ -4,6 +4,10 @@ export PYTHONPATH=nnvm/python:python:topi/python
 # to avoid openblas threading error
 export OMP_NUM_THREADS=1
 
+# Rebuild cython
+make cython || exit -1
+make cython3 || exit -1
+
 echo "Running unittest..."
 python -m nose -v nnvm/tests/python/unittest || exit -1
 python3 -m nose -v nnvm/tests/python/unittest || exit -1

tests/scripts/task_python_topi.sh

@@ -1,4 +1,8 @@
 export PYTHONPATH=python:topi/python
 
+# Rebuild cython
+make cython || exit -1
+make cython3 || exit -1
+
 python -m nose -v topi/tests/python || exit -1
 python3 -m nose -v topi/tests/python || exit -1