hw.subr

# Copyright 2017 Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# * Neither the name of Google Inc. nor the names of its contributors
#   may be used to endorse or promote products derived from this software
#   without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


# Overrides the number of CPUs returned by shtk_nw_ncpus if set to non-zero.
: ${SHTK_HW_NCPUS:=0}


shtk_hw_ncpus() {
    if [ "${SHTK_HW_NCPUS}" -gt 0 ]; then
        echo "${SHTK_HW_NCPUS}"
        return 0
    fi

    local ncpus=0
    case "$(uname -s)" in
        Darwin)
            ncpus="$(/usr/sbin/sysctl -n hw.ncpu)" || true
            ;;
        FreeBSD)
            ncpus="$(/sbin/sysctl -n hw.ncpu)" || true
            ;;
        Linux)
            ncpus="$(grep '^processor[	 ]*:' /proc/cpuinfo \
             | wc -l | awk '{print $1}')" || true
            ;;
        NetBSD)
            ncpus="$(/sbin/sysctl -n hw.ncpuonline)" || true
            ;;
    esac
    [ "${ncpus}" -gt 1 ] || ncpus=1
    echo "${ncpus}"
}