Pytorch mask-rcnn 实现细节分享

 def create_extension(name, headers, sources, verbose=True, with_cuda=False,
      package=False, relative_to='.', **kwargs):
 """Creates and configures a cffi.FFI object, that builds PyTorch extension.

 Arguments:
  name (str): package name. Can be a nested module e.g. ``.ext.my_lib``.
  headers (str or List[str]): list of headers, that contain only exported
   functions
  sources (List[str]): list of sources to compile.
  verbose (bool, optional): if set to ``False``, no output will be printed
   (de<strong style="color:transparent">本文来源gaodai#ma#com搞@@代~&码网^</strong>fault: True).
  with_cuda (bool, optional): set to ``True`` to compile with CUDA headers
   (default: False)
  package (bool, optional): set to ``True`` to build in package mode (for modules
   meant to be installed as pip packages) (default: False).
  relative_to (str, optional): path of the build file. Required when
   ``package is True``. It's best to use ``__file__`` for this argument.
  kwargs: additional arguments that are passed to ffi to declare the
   extension. See `Extension API reference`_ for details.

 .. _`Extension API reference`: https://docs.python.org/3/distutils/apiref.html#distutils.core.Extension
 """
 base_path = os.path.abspath(os.path.dirname(relative_to))
 name_suffix, target_dir = _create_module_dir(base_path, name)
 if not package:
  cffi_wrapper_name = '_' + name_suffix
 else:
  cffi_wrapper_name = (name.rpartition('.')[0] +
        '.{0}._{0}'.format(name_suffix))

 wrapper_source, include_dirs = _setup_wrapper(with_cuda)
 include_dirs.extend(kwargs.pop('include_dirs', []))

 if os.sys.platform == 'win32':
  library_dirs = glob.glob(os.getenv('CUDA_PATH', '') + '/lib/x64')
  library_dirs += glob.glob(os.getenv('NVTOOLSEXT_PATH', '') + '/lib/x64')

  here = os.path.abspath(os.path.dirname(__file__))
  lib_dir = os.path.join(here, '..', '..', 'lib')

  library_dirs.append(os.path.join(lib_dir))
 else:
  library_dirs = []
 library_dirs.extend(kwargs.pop('library_dirs', []))

 if isinstance(headers, str):
  headers = [headers]
 all_headers_source = ''
 for header in headers:
  with open(os.path.join(base_path, header), 'r') as f:
   all_headers_source += f.read() + '\n\n'

 ffi = cffi.FFI()
 sources = [os.path.join(base_path, src) for src in sources]
 # NB: TH headers are C99 now
 kwargs['extra_compile_args'] = ['-std=c99'] + kwargs.get('extra_compile_args', [])
 ffi.set_source(cffi_wrapper_name, wrapper_source + all_headers_source,
     sources=sources,
     include_dirs=include_dirs,
     library_dirs=library_dirs, **kwargs)
 ffi.cdef(_typedefs + all_headers_source)

 _make_python_wrapper(name_suffix, '_' + name_suffix, target_dir)

 def build():
  _build_extension(ffi, cffi_wrapper_name, target_dir, verbose)
 ffi.build = build
 return ffi