Don't complain about name non-uniqueness if one domain is dying. This happens

across a reboot regularly.  Inside _refresh, there is the occasion for new
domains to appear, if an existing domain reboots itself.  In this case, we
need to get the list of running domains from Xen again.

Signed-off-by: Ewan Mellor <ewan@xensource.com>

tools/python/xen/xend/XendDomain.py

@@ -357,27 +357,29 @@ class XendDomain:
         either xenstore has changed or when a method requires
         up to date information (like uptime, cputime stats).
 
+        Expects to be protected by the domains_lock.
+
         @rtype: None
         """
-        self.domains_lock.acquire()
-        try:
-            # update information for all running domains
-            # - like cpu_time, status, dying, etc.
-            running = self._running_domains()
-            for dom in running:
-                domid = dom['domid']
-                if domid in self.domains:
-                    self.domains[domid].update(dom)
 
-            # remove domains that are not running from active
-            # domain list
-            running_domids = [d['domid'] for d in running]
-            for domid, dom in self.domains.items():
-                if domid not in running_domids and domid != DOM0_ID:
-                    self._remove_domain(dom, domid)
-                    
-        finally:
-            self.domains_lock.release()
+        # update information for all running domains
+        # - like cpu_time, status, dying, etc.
+        running = self._running_domains()
+        for dom in running:
+            domid = dom['domid']
+            if domid in self.domains:
+                self.domains[domid].update(dom)
+
+        # remove domains that are not running from active domain list.
+        # The list might have changed by now, because the update call may
+        # cause new domains to be added, if the domain has rebooted.  We get
+        # the list again.
+        running = self._running_domains()
+        running_domids = [d['domid'] for d in running]
+        for domid, dom in self.domains.items():
+            if domid not in running_domids and domid != DOM0_ID:
+                self._remove_domain(dom, domid)
+
 
     def _add_domain(self, info):
         """Add the given domain entry to this instance's internal cache.
@@ -1228,8 +1230,12 @@ class XendDomain:
             elif cap < 0 or cap > dominfo.getVCpuCount() * 100:
                 raise XendError("cap is out of range")
 
+            assert type(weight) == int
+            assert type(cap) == int
+
             return xc.sched_credit_domain_set(dominfo.getDomid(), weight, cap)
         except Exception, ex:
+            log.exception(ex)
             raise XendError(str(ex))
 
     def domain_maxmem_set(self, domid, mem):

tools/python/xen/xend/XendDomainInfo.py

@@ -1353,8 +1353,6 @@ class XendDomainInfo:
             except:
                 log.exception("Removing domain path failed.")
 
-            self.info['dying'] = 0
-            self.info['shutdown'] = 0
             self._stateSet(DOM_STATE_HALTED)
         finally:
             self.refresh_shutdown_lock.release()
@@ -1626,7 +1624,7 @@ class XendDomainInfo:
             raise VmError('Invalid VM Name')
 
         dom =  XendDomain.instance().domain_lookup_nr(name)
-        if dom and dom != self:
+        if dom and dom != self and not dom.info['dying']:
             raise VmError("VM name '%s' already exists" % name)