diff options
| -rw-r--r-- | lib/local.mk | 1 | ||||
| -rw-r--r-- | lib/mutex.sh | 50 |
2 files changed, 51 insertions, 0 deletions
diff --git a/lib/local.mk b/lib/local.mk index d593289..3de79f7 100644 --- a/lib/local.mk +++ b/lib/local.mk @@ -9,6 +9,7 @@ pkgdata_sources = \ lib/control.sh \ lib/feed.sh \ lib/pkg.sh \ + lib/mutex.sh \ lib/chroot.sh \ lib/opkg.sh \ lib/rand.sh \ diff --git a/lib/mutex.sh b/lib/mutex.sh new file mode 100644 index 0000000..5fd6b70 --- /dev/null +++ b/lib/mutex.sh @@ -0,0 +1,50 @@ +# Functions for locking and unlocking mutex objects +# +# Copyright (C) 2014 Patrick "P. J." McDermott +# +# This file is part of the ProteanOS Development Kit. +# +# The ProteanOS Development Kit is free software: you can redistribute +# it and/or modify it under the terms of the GNU General Public License +# as published by the Free Software Foundation, either version 3 of the +# License, or (at your option) any later version. +# +# The ProteanOS Development Kit is distributed in the hope that it +# will be useful, but WITHOUT ANY WARRANTY; without even the implied +# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +# See the GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with the ProteanOS Development Kit. If not, see +# <http://www.gnu.org/licenses/>. + +[ "x${_MUTEX_SM+set}" = 'xset' ] && return 0 +_MUTEX_SM=1 + +mutex_trylock() +{ + local mutex="${1}" + + (set -C; printf '%d\n' "${$}" >"${mutex}") 2>/dev/null +} + +mutex_lock_timeout() +{ + local mutex="${1}" + local timeout="${2}" + + while ! mutex_trylock "${mutex}"; do + [ ${timeout} -eq 0 ] && return 1 + timeout=$(($timeout - 1)) + sleep 1 + done + + return 0 +} + +mutex_unlock() +{ + local mutex="${1}" + + rm "${mutex}" +} |