xend: serialise domain restart threads

I observed from xend.log that several domain restart threads run
simultaneously. This patch make it singleton.
Without this, several coredump of a domain might be created.

Signed-off-by: Kouya Shimura <kouya@jp.fujitsu.com>

diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index 720a1b7bb1a2cbdd42b592a807d46e8cf4b690a1..3fa2327272e6c9ccca7fe206b22d336257e40cc8 100644 (file)
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -350,6 +350,8 @@ class XendDomainInfo:
     @type shutdownWatch: xen.xend.xenstore.xswatch
     @ivar shutdownStartTime: UNIX Time when domain started shutting down.
     @type shutdownStartTime: float or None
+    @ivar restart_in_progress: Is a domain restart thread running?
+    @type restart_in_progress: bool
 #    @ivar state: Domain state
 #    @type state: enum(DOM_STATE_HALTED, DOM_STATE_RUNNING, ...)
     @ivar state_updated: lock for self.state
@@ -418,6 +420,7 @@ class XendDomainInfo:
         self.shutdownWatch = None
         self.shutdownStartTime = None
         self._resume = resume
+        self.restart_in_progress = False
 
         self.state_updated = threading.Condition()
         self.refresh_shutdown_lock = threading.Condition()
@@ -1929,7 +1932,8 @@ class XendDomainInfo:
         finally:
             self.refresh_shutdown_lock.release()
 
-        if restart_reason:
+        if restart_reason and not self.restart_in_progress:
+            self.restart_in_progress = True
             threading.Thread(target = self._maybeRestart,
                              args = (restart_reason,)).start()