work work work

• add more tooling
• improve ci
• add nanosecond measurements
• fix aio-sig
• ...

tools/check-format

+#!/usr/bin/env bash
+set -euo pipefail
+
+# Pretty fancy method to get reliable the absolute path of a shell
+# script, *even if it is sourced*. Credits go to GreenFox on
+# stackoverflow: http://stackoverflow.com/a/12197518/194894
+pushd . > /dev/null
+SCRIPTDIR="${BASH_SOURCE[0]}";
+while([ -h "${SCRIPTDIR}" ]); do
+    cd "`dirname "${SCRIPTDIR}"`"
+    SCRIPTDIR="$(readlink "`basename "${SCRIPTDIR}"`")";
+done
+cd "`dirname "${SCRIPTDIR}"`" > /dev/null
+SCRIPTDIR="`pwd`";
+popd  > /dev/null
+
+DEBUG=false
+while getopts d OPT; do
+	case $OPT in
+		d)
+			set -x
+			DEBUG=true
+			;;
+		*)
+			echo "usage: ${0##*/} [-dq} [--] ARGS..."
+			exit 2
+	esac
+done
+shift $(( OPTIND - 1 ))
+OPTIND=1
+
+ROOTDIR=$(readlink -f "${SCRIPTDIR}/..")
+
+MAX_PROCS=$(nproc)
+
+CHECKED_FILES_FILE=$(mktemp)
+if ! $DEBUG; then
+	trap 'rm "${CHECKED_FILES_FILE}"' EXIT
+fi
+
+cd "${ROOTDIR}"
+# Note that the --dry-run and --Werror clang-format arguments require
+# clang-format 10 or higher. See https://reviews.llvm.org/D68554
+find . \( -path '*/\.*' -o -path "./subprojects*" -o -path "./build*" \) -prune -o \
+	-type f -regextype posix-extended -regex '.*\.(c|h|cpp|hpp)' -print0 |\
+	tee "${CHECKED_FILES_FILE}" |\
+	xargs --null --max-args=3 --max-procs="${MAX_PROCS}" \
+		  clang-format --style=file --dry-run -Werror
+
+FILE_COUNT=$(<"${CHECKED_FILES_FILE}" tr -cd '\0' | wc -c)
+echo "Checked ${FILE_COUNT} files for format violations"