mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 08:58:07 +00:00
8c0089882a
Starting with GNU make 4.4, --jobserver-auth newly uses named pipe (fifo) instead of part of opened file descriptors: https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html Support also the new format. Signed-off-by: Martin Liska <mliska@suse.cz> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
77 lines
2.6 KiB
Python
Executable file
77 lines
2.6 KiB
Python
Executable file
#!/usr/bin/env python3
|
|
# SPDX-License-Identifier: GPL-2.0+
|
|
#
|
|
# This determines how many parallel tasks "make" is expecting, as it is
|
|
# not exposed via an special variables, reserves them all, runs a subprocess
|
|
# with PARALLELISM environment variable set, and releases the jobs back again.
|
|
#
|
|
# https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver
|
|
from __future__ import print_function
|
|
import os, sys, errno
|
|
import subprocess
|
|
|
|
# Extract and prepare jobserver file descriptors from environment.
|
|
claim = 0
|
|
jobs = b""
|
|
try:
|
|
# Fetch the make environment options.
|
|
flags = os.environ['MAKEFLAGS']
|
|
|
|
# Look for "--jobserver=R,W"
|
|
# Note that GNU Make has used --jobserver-fds and --jobserver-auth
|
|
# so this handles all of them.
|
|
opts = [x for x in flags.split(" ") if x.startswith("--jobserver")]
|
|
|
|
# Parse out R,W file descriptor numbers and set them nonblocking.
|
|
# If the MAKEFLAGS variable contains multiple instances of the
|
|
# --jobserver-auth= option, the last one is relevant.
|
|
fds = opts[-1].split("=", 1)[1]
|
|
|
|
# Starting with GNU Make 4.4, named pipes are used for reader and writer.
|
|
# Example argument: --jobserver-auth=fifo:/tmp/GMfifo8134
|
|
_, _, path = fds.partition('fifo:')
|
|
|
|
if path:
|
|
reader = os.open(path, os.O_RDONLY | os.O_NONBLOCK)
|
|
writer = os.open(path, os.O_WRONLY)
|
|
else:
|
|
reader, writer = [int(x) for x in fds.split(",", 1)]
|
|
# Open a private copy of reader to avoid setting nonblocking
|
|
# on an unexpecting process with the same reader fd.
|
|
reader = os.open("/proc/self/fd/%d" % (reader),
|
|
os.O_RDONLY | os.O_NONBLOCK)
|
|
|
|
# Read out as many jobserver slots as possible.
|
|
while True:
|
|
try:
|
|
slot = os.read(reader, 8)
|
|
jobs += slot
|
|
except (OSError, IOError) as e:
|
|
if e.errno == errno.EWOULDBLOCK:
|
|
# Stop at the end of the jobserver queue.
|
|
break
|
|
# If something went wrong, give back the jobs.
|
|
if len(jobs):
|
|
os.write(writer, jobs)
|
|
raise e
|
|
# Add a bump for our caller's reserveration, since we're just going
|
|
# to sit here blocked on our child.
|
|
claim = len(jobs) + 1
|
|
except (KeyError, IndexError, ValueError, OSError, IOError) as e:
|
|
# Any missing environment strings or bad fds should result in just
|
|
# not being parallel.
|
|
pass
|
|
|
|
# We can only claim parallelism if there was a jobserver (i.e. a top-level
|
|
# "-jN" argument) and there were no other failures. Otherwise leave out the
|
|
# environment variable and let the child figure out what is best.
|
|
if claim > 0:
|
|
os.environ['PARALLELISM'] = '%d' % (claim)
|
|
|
|
rc = subprocess.call(sys.argv[1:])
|
|
|
|
# Return all the reserved slots.
|
|
if len(jobs):
|
|
os.write(writer, jobs)
|
|
|
|
sys.exit(rc)
|