require_cpu functionality (#6336)

* add require_cpu from Thinc 8.0.0rc2

* add docs

* fix test if cupy is not installed

pyproject.toml

@@ -6,7 +6,7 @@ requires = [
     "cymem>=2.0.2,<2.1.0",
     "preshed>=3.0.2,<3.1.0",
     "murmurhash>=0.28.0,<1.1.0",
-    "thinc>=8.0.0rc0,<8.1.0",
+    "thinc>=8.0.0rc2,<8.1.0",
     "blis>=0.4.0,<0.8.0",
     "pathy"
 ]

requirements.txt

@@ -1,7 +1,7 @@
 # Our libraries
 cymem>=2.0.2,<2.1.0
 preshed>=3.0.2,<3.1.0
-thinc>=8.0.0rc0,<8.1.0
+thinc>=8.0.0rc2,<8.1.0
 blis>=0.4.0,<0.8.0
 ml_datasets==0.2.0a0
 murmurhash>=0.28.0,<1.1.0

setup.cfg

@@ -34,13 +34,13 @@ setup_requires =
     cymem>=2.0.2,<2.1.0
     preshed>=3.0.2,<3.1.0
     murmurhash>=0.28.0,<1.1.0
-    thinc>=8.0.0rc0,<8.1.0
+    thinc>=8.0.0rc2,<8.1.0
 install_requires =
     # Our libraries
     murmurhash>=0.28.0,<1.1.0
     cymem>=2.0.2,<2.1.0
     preshed>=3.0.2,<3.1.0
-    thinc>=8.0.0rc0,<8.1.0
+    thinc>=8.0.0rc2,<8.1.0
     blis>=0.4.0,<0.8.0
     wasabi>=0.8.0,<1.1.0
     srsly>=2.3.0,<3.0.0

spacy/__init__.py

@@ -7,7 +7,7 @@ warnings.filterwarnings("ignore", message="numpy.dtype size changed")  # noqa
 warnings.filterwarnings("ignore", message="numpy.ufunc size changed")  # noqa
 
 # These are imported as part of the API
-from thinc.api import prefer_gpu, require_gpu  # noqa: F401
+from thinc.api import prefer_gpu, require_gpu, require_cpu  # noqa: F401
 from thinc.api import Config
 
 from . import pipeline  # noqa: F401

spacy/tests/test_misc.py

@@ -4,7 +4,7 @@ import ctypes
 from pathlib import Path
 from spacy.about import __version__ as spacy_version
 from spacy import util
-from spacy import prefer_gpu, require_gpu
+from spacy import prefer_gpu, require_gpu, require_cpu
 from spacy.ml._precomputable_affine import PrecomputableAffine
 from spacy.ml._precomputable_affine import _backprop_precomputable_affine_padding
 from spacy.util import dot_to_object, SimpleFrozenList
@@ -15,6 +15,8 @@ from spacy.lang.nl import Dutch
 from spacy.language import DEFAULT_CONFIG_PATH
 from spacy.schemas import ConfigSchemaTraining
 
+from thinc.api import get_current_ops, NumpyOps, CupyOps
+
 from .util import get_random_doc
 
 
@@ -81,6 +83,8 @@ def test_PrecomputableAffine(nO=4, nI=5, nF=3, nP=2):
 def test_prefer_gpu():
     try:
         import cupy  # noqa: F401
+        prefer_gpu()
+        assert isinstance(get_current_ops(), CupyOps)
     except ImportError:
         assert not prefer_gpu()
 
@@ -88,10 +92,24 @@ def test_prefer_gpu():
 def test_require_gpu():
     try:
         import cupy  # noqa: F401
+        require_gpu()
+        assert isinstance(get_current_ops(), CupyOps)
     except ImportError:
         with pytest.raises(ValueError):
             require_gpu()
 
+def test_require_cpu():
+    require_cpu()
+    assert isinstance(get_current_ops(), NumpyOps)
+    try:
+        import cupy  # noqa: F401
+        require_gpu()
+        assert isinstance(get_current_ops(), CupyOps)
+    except ImportError:
+        pass
+    require_cpu()
+    assert isinstance(get_current_ops(), NumpyOps)
+
 
 def test_ascii_filenames():
     """Test that all filenames in the project are ASCII.

website/docs/api/top-level.md

@@ -171,6 +171,25 @@ and _before_ loading any pipelines.
 | `gpu_id`    | Device index to select. Defaults to `0`. ~~int~~ |
 | **RETURNS** | `True` ~~bool~~                                  |
 
+### spacy.require_cpu {#spacy.require_cpu tag="function" new="3.0.0"}
+
+Allocate data and perform operations on CPU. 
+If data has already been allocated on GPU, it will not
+be moved. Ideally, this function should be called right after importing spaCy
+and _before_ loading any pipelines.
+
+> #### Example
+>
+> ```python
+> import spacy
+> spacy.require_cpu()
+> nlp = spacy.load("en_core_web_sm")
+> ```
+
+| Name        | Description                                      |
+| ----------- | ------------------------------------------------ |
+| **RETURNS** | `True` ~~bool~~                                  |
+
 ## displaCy {#displacy source="spacy/displacy"}
 
 As of v2.0, spaCy comes with a built-in visualization suite. For more info and