[gentoo-dev] [PATCH v2] distutils-r1.eclass: Enable parallel builds in py3.5+

[gentoo-dev] [PATCH v2] distutils-r1.eclass: Enable parallel builds in py3.5+

[Michał Górny]

Python 3.5+ introduces parallel build support in distutils.  Take
advantage of that by passing appropriate -j option.  Since distutils
does not support an equivalent of --load-average, default to the number
of CPUs+1 when unspecified.

In order to avoid breaking stable systems, introduce the new behavior
only for EAPI 7 ebuilds, or older EAPI ebuilds with unstable
implementations (Python 3.7 and PyPy 3).
---
 eclass/distutils-r1.eclass | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/eclass/distutils-r1.eclass b/eclass/distutils-r1.eclass
index 975383acc09b..85f8f4cb3be9 100644
--- a/eclass/distutils-r1.eclass
+++ b/eclass/distutils-r1.eclass
@@ -80,10 +80,10 @@ if [[ ! ${_DISTUTILS_R1} ]]; then
 
 [[ ${EAPI} == [45] ]] && inherit eutils
 [[ ${EAPI} == [56] ]] && inherit xdg-utils
-inherit toolchain-funcs
+inherit multiprocessing toolchain-funcs
 
 if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
-	inherit multiprocessing python-r1
+	inherit python-r1
 else
 	inherit python-single-r1
 fi
@@ -454,7 +454,23 @@ distutils-r1_python_compile() {
 
 	_distutils-r1_copy_egg_info
 
-	esetup.py build "${@}"
+	local build_args=()
+	# distutils is parallel-capable since py3.5
+	# to avoid breaking stable ebuilds, enable it only if either:
+	# a. we're dealing with EAPI 7
+	# b. we're dealing with Python 3.7 or PyPy3
+	if python_is_python3 && [[ ${EPYTHON} != python3.4 ]]; then
+		if [[ ${EAPI} != [56] || ${EPYTHON} != python3.[56] ]]; then
+			local jobs=$(makeopts_jobs "${MAKEOPTS}" INF)
+			if [[ ${jobs} == INF ]]; then
+				local nproc=$(get_nproc)
+				jobs=$(( nproc + 1 ))
+			fi
+			build_args+=( -j "${jobs}" )
+		fi
+	fi
+
+	esetup.py build "${build_args[@]}" "${@}"
 }
 
 # @FUNCTION: _distutils-r1_wrap_scripts
-- 
2.18.0

Re: [gentoo-dev] [PATCH v2] distutils-r1.eclass: Enable parallel builds in py3.5+

[Mike Gilbert]

On Thu, Jul 19, 2018 at 11:01 AM, Michał Górny <mgorny@gentoo.org> wrote:
> Python 3.5+ introduces parallel build support in distutils.  Take
> advantage of that by passing appropriate -j option.  Since distutils
> does not support an equivalent of --load-average, default to the number
> of CPUs+1 when unspecified.
>
> In order to avoid breaking stable systems, introduce the new behavior
> only for EAPI 7 ebuilds, or older EAPI ebuilds with unstable
> implementations (Python 3.7 and PyPy 3).

Looks good to me.