The attached patch breaks out

- log() function from xen-hotplug-common.sh -> logging.sh
- locking-related functions from xen-hotplug-common.sh  -> locking.sh

- xen-hotplug-common.sh 'sources' both those files now to not loose
these functions (which should make the break-out atomic)

- adapts the Makefile to install locking.sh and logging.sh at the right
place.

I ran the xm-tests over it and no (additional) errors appear due to this
change.

Signed-off-by: Stefan Berger <stefanb@us.ibm.com>

tools/examples/Makefile

@@ -27,7 +27,7 @@ XEN_SCRIPTS += network-nat vif-nat
 XEN_SCRIPTS += block
 XEN_SCRIPTS += block-enbd block-nbd
 XEN_SCRIPTS += vtpm
-XEN_SCRIPT_DATA = xen-script-common.sh
+XEN_SCRIPT_DATA = xen-script-common.sh locking.sh logging.sh
 XEN_SCRIPT_DATA += xen-hotplug-common.sh xen-network-common.sh vif-common.sh
 XEN_SCRIPT_DATA += block-common.sh vtpm-common.sh
 

tools/examples/xen-hotplug-common.sh

@@ -17,7 +17,9 @@
 
 
 dir=$(dirname "$0")
+. "$dir/logging.sh"
 . "$dir/xen-script-common.sh"
+. "$dir/locking.sh"
 
 exec 2>>/var/log/xen-hotplug.log
 
@@ -25,12 +27,6 @@ export PATH="/sbin:/bin:/usr/bin:/usr/sbin:$PATH"
 export LANG="POSIX"
 unset $(set | grep ^LC_ | cut -d= -f1)
 
-log() {
-  local level="$1"
-  shift
-  logger -p "daemon.$level" -- "$0:" "$@" || echo "$0 $@" >&2
-}
-
 fatal() {
   xenstore_write "$XENBUS_PATH"/hotplug-status error
   log err "$@"
@@ -93,87 +89,4 @@ xenstore_write() {
 }
 
 
-#
-# Serialisation
-#
-
-LOCK_SLEEPTIME=1
-LOCK_SPINNING_RETRIES=5
-LOCK_RETRIES=10
-LOCK_BASEDIR=/var/run/xen-hotplug
-
-
-claim_lock()
-{
-  local lockdir="$LOCK_BASEDIR/$1"
-  mkdir -p "$LOCK_BASEDIR"
-  _claim_lock "$lockdir"
-}
-
-
-release_lock()
-{
-  _release_lock "$LOCK_BASEDIR/$1"
-}
-
-
-_claim_lock()
-{
-  local lockdir="$1"
-  local owner=$(_lock_owner "$lockdir")
-  local retries=0
-
-  while [ $retries -lt $LOCK_RETRIES ]
-  do
-    mkdir "$lockdir" 2>/dev/null && trap "release_lock $1; sigerr" ERR &&
-      _update_lock_info "$lockdir" && return
-
-    local new_owner=$(_lock_owner "$lockdir")
-    if [ "$new_owner" != "$owner" ]
-    then
-      owner="$new_owner"
-      retries=0
-    fi
-
-    if [ $retries -gt $LOCK_SPINNING_RETRIES ]
-    then
-      sleep $LOCK_SLEEPTIME
-    else
-      sleep 0
-    fi
-    retries=$(($retries + 1))
-  done
-  _steal_lock "$lockdir"
-}
-
-
-_release_lock()
-{
-  trap sigerr ERR
-  rm -rf "$1" 2>/dev/null || true
-}
-
-
-_steal_lock()
-{
-  local lockdir="$1"
-  local owner=$(cat "$lockdir/owner" 2>/dev/null || echo "unknown")
-  log err "Forced to steal lock on $lockdir from $owner!"
-  _release_lock "$lockdir"
-  _claim_lock "$lockdir"
-}
-
-
-_lock_owner()
-{
-  cat "$1/owner" 2>/dev/null || echo "unknown"
-}
-
-
-_update_lock_info()
-{
-  echo "$$: $0" >"$1/owner"
-}
-
-
 log debug "$@" "XENBUS_PATH=$XENBUS_PATH"

xen-unstable.hg/tools/examples/locking.sh

@@ -0,0 +1,98 @@
+#
+# Copyright (c) 2005 XenSource Ltd.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of version 2.1 of the GNU Lesser General Public
+# License as published by the Free Software Foundation.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+#
+# Serialisation
+#
+
+LOCK_SLEEPTIME=1
+LOCK_SPINNING_RETRIES=5
+LOCK_RETRIES=10
+LOCK_BASEDIR=/var/run/xen-hotplug
+
+
+claim_lock()
+{
+  local lockdir="$LOCK_BASEDIR/$1"
+  mkdir -p "$LOCK_BASEDIR"
+  _claim_lock "$lockdir"
+}
+
+
+release_lock()
+{
+  _release_lock "$LOCK_BASEDIR/$1"
+}
+
+
+_claim_lock()
+{
+  local lockdir="$1"
+  local owner=$(_lock_owner "$lockdir")
+  local retries=0
+
+  while [ $retries -lt $LOCK_RETRIES ]
+  do
+    mkdir "$lockdir" 2>/dev/null && trap "release_lock $1; sigerr" ERR &&
+      _update_lock_info "$lockdir" && return
+
+    local new_owner=$(_lock_owner "$lockdir")
+    if [ "$new_owner" != "$owner" ]
+    then
+      owner="$new_owner"
+      retries=0
+    fi
+
+    if [ $retries -gt $LOCK_SPINNING_RETRIES ]
+    then
+      sleep $LOCK_SLEEPTIME
+    else
+      sleep 0
+    fi
+    retries=$(($retries + 1))
+  done
+  _steal_lock "$lockdir"
+}
+
+
+_release_lock()
+{
+  trap sigerr ERR
+  rm -rf "$1" 2>/dev/null || true
+}
+
+
+_steal_lock()
+{
+  local lockdir="$1"
+  local owner=$(cat "$lockdir/owner" 2>/dev/null || echo "unknown")
+  log err "Forced to steal lock on $lockdir from $owner!"
+  _release_lock "$lockdir"
+  _claim_lock "$lockdir"
+}
+
+
+_lock_owner()
+{
+  cat "$1/owner" 2>/dev/null || echo "unknown"
+}
+
+
+_update_lock_info()
+{
+  echo "$$: $0" >"$1/owner"
+}

xen-unstable.hg/tools/examples/logging.sh

@@ -0,0 +1,22 @@
+#
+# Copyright (c) 2005 XenSource Ltd.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of version 2.1 of the GNU Lesser General Public
+# License as published by the Free Software Foundation.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+log() {
+  local level="$1"
+  shift
+  logger -p "daemon.$level" -- "$0:" "$@" || echo "$0 $@" >&2
+}