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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /scripts/jobserver-exec | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'scripts/jobserver-exec')
-rwxr-xr-x | scripts/jobserver-exec | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec new file mode 100755 index 000000000..0fdb31a79 --- /dev/null +++ b/scripts/jobserver-exec @@ -0,0 +1,66 @@ +#!/usr/bin/env python +# 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 envirnoment. +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. + fds = opts[0].split("=", 1)[1] + 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) |