add python monkey-patch for parallel build_ext compilation

2 files changed, 66 insertions, 0 deletions

diff --git a/tools/distrib/python/grpcio_tools/_parallel_compile_patch.py b/tools/distrib/python/grpcio_tools/_parallel_compile_patch.py
new file mode 100644
index 0000000000..4d03ef49ba
--- /dev/null
+++ b/tools/distrib/python/grpcio_tools/_parallel_compile_patch.py
@@ -0,0 +1,63 @@
+# Copyright 2018 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Patches the compile() to allow enable parallel compilation of C/C++.
+
+build_ext has lots of C/C++ files and normally them one by one.
+Enabling parallel build helps a lot.
+"""
+
+import distutils.ccompiler
+import os
+
+try:
+    BUILD_EXT_COMPILER_JOBS = int(
+        os.environ.get('GRPC_PYTHON_BUILD_EXT_COMPILER_JOBS', '1'))
+except ValueError:
+    BUILD_EXT_COMPILER_JOBS = 1
+
+
+# monkey-patch for parallel compilation
+def _parallel_compile(self,
+                      sources,
+                      output_dir=None,
+                      macros=None,
+                      include_dirs=None,
+                      debug=0,
+                      extra_preargs=None,
+                      extra_postargs=None,
+                      depends=None):
+    # setup the same way as distutils.ccompiler.CCompiler
+    # https://github.com/python/cpython/blob/31368a4f0e531c19affe2a1becd25fc316bc7501/Lib/distutils/ccompiler.py#L564
+    macros, objects, extra_postargs, pp_opts, build = self._setup_compile(
+        output_dir, macros, include_dirs, sources, depends, extra_postargs)
+    cc_args = self._get_cc_args(pp_opts, debug, extra_preargs)
+
+    def _compile_single_file(obj):
+        try:
+            src, ext = build[obj]
+        except KeyError:
+            return
+        self._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)
+
+    # run compilation of individual files in parallel
+    import multiprocessing.pool
+    multiprocessing.pool.ThreadPool(BUILD_EXT_COMPILER_JOBS).map(
+        _compile_single_file, objects)
+    return objects
+
+
+def monkeypatch_compile_maybe():
+    """Monkeypatching is dumb, but the build speed gain is worth it."""
+    if BUILD_EXT_COMPILER_JOBS > 1:
+        distutils.ccompiler.CCompiler.compile = _parallel_compile
diff --git a/tools/distrib/python/grpcio_tools/setup.py b/tools/distrib/python/grpcio_tools/setup.py
index c13dfe9ade..64c468cbf7 100644
--- a/tools/distrib/python/grpcio_tools/setup.py
+++ b/tools/distrib/python/grpcio_tools/setup.py
@@ -34,9 +34,12 @@ from setuptools.command import build_ext
 os.chdir(os.path.dirname(os.path.abspath(__file__)))
 sys.path.insert(0, os.path.abspath('.'))
 
+import _parallel_compile_patch
 import protoc_lib_deps
 import grpc_version
 
+_parallel_compile_patch.monkeypatch_compile_maybe()
+
 CLASSIFIERS = [
     'Development Status :: 5 - Production/Stable',
     'Programming Language :: Python',