lib/common.sh: Introduce locking helper functions

Reduces code duplication.

With makechrootpkg not calling mkarchroot anymore,
the lock handover protocol is unneeded.

arch-nspawn does not do any locking, so add protection to archbuild.

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/common.sh b/lib/common.sh
index b39bbbc..9446ff5 100644
--- a/lib/common.sh
+++ b/lib/common.sh
@@ -130,3 +130,27 @@ get_full_version() {
 		fi
 	fi
 }
+
+##
+#  usage : lock( $fd, $file, $message )
+##
+lock() {
+	eval "exec $1>"'"$2"'
+	if ! flock -n $1; then
+		stat_busy "$3"
+		flock $1
+		stat_done
+	fi
+}
+
+##
+#  usage : slock( $fd, $file, $message )
+##
+slock() {
+	eval "exec $1>"'"$2"'
+	if ! flock -sn $1; then
+		stat_busy "$3"
+		flock -s $1
+		stat_done
+	fi
+}