From e761fdb8874e00ee14b7b64336b744429349ef79 Mon Sep 17 00:00:00 2001
From: Marko Bencun <mbencun@gmail.com>
Date: Wed, 11 Sep 2013 13:55:51 +0200
Subject: [PATCH] improved buffer interface
---
pyopencl/__init__.py | 1 -
pyopencl/cffi_cl.py | 46 +++++++++++++++++++++++++++++++-------------
2 files changed, 33 insertions(+), 14 deletions(-)
diff --git a/pyopencl/__init__.py b/pyopencl/__init__.py
index 52862916..2ad94445 100644
--- a/pyopencl/__init__.py
+++ b/pyopencl/__init__.py
@@ -475,7 +475,6 @@ def _add_functionality():
self.set_arg(i, arg)
else:
from pyopencl._pvt_struct import pack
-
for i, (arg, arg_type_char) in enumerate(
zip(args, arg_type_chars)):
if arg_type_char and arg_type_char != "V":
diff --git a/pyopencl/cffi_cl.py b/pyopencl/cffi_cl.py
index 16edab64..fe255b57 100644
--- a/pyopencl/cffi_cl.py
+++ b/pyopencl/cffi_cl.py
@@ -204,18 +204,35 @@ class MemoryObjectHolder(_Common):
class MemoryObject(MemoryObjectHolder):
pass
-
def _c_buffer_from_obj(obj, writable=False):
+ """
+ Convert a Python object to a tuple (cdata('void *'), num_bytes, dummy) to be able to pass
+ a data stream to a C function. The dummy variable exists only to ensure that the Python object referencing the
+ C buffer is not garbage collected at the end of this function, making the C buffer itself invalid.
+ """
+
if obj is None:
return _ffi.NULL, 0
- # numpy array
- if hasattr(obj, '__array_interface__'): # if writeable == False, some tests fail...
- return _ffi.cast('void *', obj.__array_interface__['data'][0]), obj.nbytes
+ # CPYthon: use the old buffer protocol
+
+ # {{{ special case: numpy (also works with numpypy)
+ if isinstance(obj, np.ndarray):
+ # numpy array
+ return _ffi.cast('void *', obj.__array_interface__['data'][0]), obj.nbytes, None
+ if isinstance(obj, np.generic):
+ # numpy scalar
+ # * obj.__array_interface__ exists in CPython, but the address does not seem to point
+ # to the actual scalar (not supported/bug?).
+ # * does not exist (yet?) in numpypy.
+ s_array = np.array([obj]) # obj[()] not supported yet by numpypy
+ return _ffi.cast('void *', s_array.__array_interface__['data'][0]), s_array.nbytes, s_array
- # ... ?
+ # }}}
+
+ # TODO: is there a cross-interpreter solution?
- # fall back to old CPython buffer protocol API
+ # {{{ fall back to the old CPython buffer protocol API
addr = ctypes.c_void_p()
length = ctypes.c_ssize_t()
try:
@@ -228,7 +245,10 @@ def _c_buffer_from_obj(obj, writable=False):
else:
if status:
raise Exception('TODO error_already_set')
- return _ffi.cast('void *', addr.value), length.value
+ print addr.value, length
+ return _ffi.cast('void *', addr.value), length.value, None
+
+ # }}}
class Buffer(MemoryObject):
_id = 'buffer'
@@ -237,7 +257,7 @@ class Buffer(MemoryObject):
warnings.warn("'hostbuf' was passed, but no memory flags to make use of it.")
c_hostbuf = _ffi.NULL
if hostbuf is not None:
- c_hostbuf, hostbuf_size = _c_buffer_from_obj(hostbuf, writable=flags & mem_flags.USE_HOST_PTR)
+ c_hostbuf, hostbuf_size, _ = _c_buffer_from_obj(hostbuf, writable=flags & mem_flags.USE_HOST_PTR)
if size > hostbuf_size:
raise RuntimeError("Buffer", status_code.INVALID_VALUE, "specified size is greater than host buffer size")
if size == 0:
@@ -383,7 +403,7 @@ class Kernel(_Common):
_handle_error(_lib.kernel__set_arg_sampler(self.ptr, arg_index, arg.ptr))
else:
# todo: how to handle args other than numpy arrays?
- c_buf, size = _c_buffer_from_obj(arg)
+ c_buf, size, _ = _c_buffer_from_obj(arg)
_handle_error(_lib.kernel__set_arg_buf(self.ptr, arg_index, c_buf, size))
def get_work_group_info(self, param, device):
@@ -467,7 +487,7 @@ def _c_obj_list(objs=None):
return _ffi.new('void *[]', [ev.ptr for ev in objs]), len(objs)
def _enqueue_read_buffer(queue, mem, hostbuf, device_offset=0, wait_for=None, is_blocking=True):
- c_buf, size = _c_buffer_from_obj(hostbuf, writable=True)
+ c_buf, size, _ = _c_buffer_from_obj(hostbuf, writable=True)
ptr_event = _ffi.new('void **')
c_wait_for, num_wait_for = _c_obj_list(wait_for)
_handle_error(_lib._enqueue_read_buffer(
@@ -498,7 +518,7 @@ def _enqueue_copy_buffer(queue, src, dst, byte_count=-1, src_offset=0, dst_offse
return _create_instance(Event, ptr_event[0])
def _enqueue_write_buffer(queue, mem, hostbuf, device_offset=0, wait_for=None, is_blocking=True):
- c_buf, size = _c_buffer_from_obj(hostbuf)
+ c_buf, size, _ = _c_buffer_from_obj(hostbuf)
ptr_event = _ffi.new('void **')
c_wait_for, num_wait_for = _c_obj_list(wait_for)
_handle_error(_lib._enqueue_write_buffer(
@@ -514,7 +534,7 @@ def _enqueue_write_buffer(queue, mem, hostbuf, device_offset=0, wait_for=None, i
return _create_instance(Event, ptr_event[0])
def _enqueue_read_image(queue, mem, origin, region, hostbuf, row_pitch=0, slice_pitch=0, wait_for=None, is_blocking=True):
- c_buf, size = _c_buffer_from_obj(hostbuf, writable=True)
+ c_buf, size, _ = _c_buffer_from_obj(hostbuf, writable=True)
ptr_event = _ffi.new('void **')
c_wait_for, num_wait_for = _c_obj_list(wait_for)
_handle_error(_lib._enqueue_read_image(
@@ -675,7 +695,7 @@ class Image(MemoryObject):
if shape is None:
raise LogicError("Image", status_code.INVALID_VALUE, "'shape' must be given")
- c_buf, size = _c_buffer_from_obj(buffer, writable=flags & mem_flags.USE_HOST_PTR)
+ c_buf, size, _ = _c_buffer_from_obj(buffer, writable=flags & mem_flags.USE_HOST_PTR)
dims = len(shape)
if dims == 2:
--
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