diff --git a/lib/cache.coffee b/lib/cache.coffee
index 86aec86..dfb316b 100644
--- a/lib/cache.coffee
+++ b/lib/cache.coffee
@@ -93,18 +93,18 @@ refresh = (callback) ->
 
     lock('presets_hash_lock', 3000, (err, unlockOrExtend) ->
       return callback(err) if err
-      counter = 4
+      counter = 3
+
+      counter += 2
       db.presetsCollection.find().toArray((err, res) ->
         if err
-          callback(err) if -- counter >= 0
-          counter = 0
-          return
+          callback(err) if counter & 1
+          return counter = 0
 
         db.objectsCollection.find().toArray((err, objects) ->
           if err
-            callback(err) if -- counter >= 0
-            counter = 0
-            return
+            callback(err) if (counter & 1)
+            return counter = 0
 
           res.sort((a, b) ->
             if a.weight == b.weight
@@ -167,13 +167,12 @@ refresh = (callback) ->
                       p = "#{c.name}.[#{alias}]"
                       _provisions.push(['instances', p, 0])
                 else
-                  callback(new Error("Unknown configuration type #{c.type}")) if -- counter >= 0
-                  counter = 0
-                  return
+                  callback(new Error("Unknown configuration type #{c.type}")) if counter & 1
+                  return counter = 0
 
             presets.push({name: preset._id, channel: preset.channel or 'default', schedule: schedule, events: events, precondition: precondition, provisions: _provisions})
 
-          if -- counter == 0
+          if (counter -= 2) == 1
             computeHash()
             db.redisClient.setex("presets_hash", 300, hash, (err) ->
               unlockOrExtend(0)
@@ -183,11 +182,11 @@ refresh = (callback) ->
         )
       )
 
+      counter += 2
       db.provisionsCollection.find().toArray((err, res) ->
         if err
-          callback(err) if -- counter >= 0
-          counter = 0
-          return
+          callback(err) if counter & 1
+          return counter = 0
 
         provisions = {}
         for r in res
@@ -195,7 +194,7 @@ refresh = (callback) ->
           provisions[r._id].md5 = crypto.createHash('md5').update(r.script).digest('hex')
           provisions[r._id].script = new vm.Script("\"use strict\";(function(){\n#{r.script}\n})();", {filename: r._id, lineOffset: 1, timeout: 50})
 
-        if -- counter == 0
+        if (counter -= 2) == 1
           computeHash()
           db.redisClient.setex("presets_hash", 300, hash, (err) ->
             unlockOrExtend(0)
@@ -204,11 +203,11 @@ refresh = (callback) ->
           )
       )
 
+      counter += 2
       db.virtualParametersCollection.find().toArray((err, res) ->
         if err
-          callback(err) if -- counter >= 0
-          counter = 0
-          return
+          callback(err) if counter & 1
+          return counter = 0
 
         virtualParameters = {}
         for r in res
@@ -216,7 +215,7 @@ refresh = (callback) ->
           virtualParameters[r._id].md5 = crypto.createHash('md5').update(r.script).digest('hex')
           virtualParameters[r._id].script = new vm.Script("\"use strict\";(function(){\n#{r.script}\n})();", {filename: r._id, lineOffset: 1, timeout: 50})
 
-        if -- counter == 0
+        if (counter -= 2) == 1
           computeHash()
           db.redisClient.setex("presets_hash", 300, hash, (err) ->
             unlockOrExtend(0)
@@ -225,11 +224,11 @@ refresh = (callback) ->
           )
       )
 
+      counter += 2
       db.filesCollection.find().toArray((err, res) ->
         if err
-          callback(err) if -- counter >= 0
-          counter = 0
-          return
+          callback(err) if counter & 1
+          return counter = 0
 
         files = {}
         for r in res
@@ -239,7 +238,7 @@ refresh = (callback) ->
           files[id].md5 = r.md5
           files[id].contentType = r.contentType
 
-        if -- counter == 0
+        if (counter -= 2) == 1
           computeHash()
           db.redisClient.setex("presets_hash", 300, hash, (err) ->
             unlockOrExtend(0)
@@ -247,6 +246,14 @@ refresh = (callback) ->
             return callback()
           )
       )
+
+      if (counter -= 2) == 1
+        computeHash()
+        db.redisClient.setex("presets_hash", 300, hash, (err) ->
+          unlockOrExtend(0)
+          nextRefresh = now + REFRESH
+          return callback()
+        )
     )
   )
 
diff --git a/lib/cwmp.coffee b/lib/cwmp.coffee
index c271e4d..6766d91 100644
--- a/lib/cwmp.coffee
+++ b/lib/cwmp.coffee
@@ -429,31 +429,31 @@ sendRpcRequest = (currentRequest, id, rpcRequest) ->
       db.clearTasks(currentRequest.sessionData.doneTasks, (err) ->
         return throwError(err, currentRequest.httpResponse) if err
 
-        counter = 1
+        counter = 3
 
         for k of currentRequest.sessionData.faultsTouched
-          ++ counter
+          counter += 2
           if currentRequest.sessionData.faults[k]
             currentRequest.sessionData.faults[k].retries = currentRequest.sessionData.retries[k]
             db.saveFault(currentRequest.sessionData.deviceId, k, currentRequest.sessionData.faults[k], (err) ->
-              -- counter
-              if err and counter >= 0
-                return throwError(err, currentRequest.httpResponse) if err
+              if err
+                throwError(err, currentRequest.httpResponse) if counter & 1
+                return counter = 0
 
-              if counter == 0
+              if (counter -= 2) == 1
                 return writeResponse(currentRequest, soap.response(null))
             )
           else
             db.deleteFault(currentRequest.sessionData.deviceId, k, (err) ->
-              -- counter
-              if err and counter >= 0
-                return throwError(err, currentRequest.httpResponse) if err
+              if err
+                throwError(err, currentRequest.httpResponse) if counter & 1
+                return counter = 0
 
-              if counter == 0
+              if (counter -= 2) == 1
                 return writeResponse(currentRequest, soap.response(null))
             )
 
-        if -- counter == 0
+        if (counter -= 2) == 1
           return writeResponse(currentRequest, soap.response(null))
       )
     )
diff --git a/lib/sandbox.js b/lib/sandbox.js
index 2afe369..d03f443 100644
--- a/lib/sandbox.js
+++ b/lib/sandbox.js
@@ -275,16 +275,17 @@ function run(script, globals, timestamp, deviceData, extensionsCache, startRevis
   let extCache = sandbox.extensionsCache;
   let args = arguments;
 
-  let counter = 1;
+  let counter = 3;
   for (let key in sandbox.extensions) {
-    ++ counter;
+    counter += 2;
     extensions.run(sandbox.extensions[key], function(err, fault, res) {
-      if ((err || fault) && counter > 0) {
-        counter = 0;
-        return callback(err, fault);
+      if (err || fault) {
+        if (counter & 1)
+          callback(err, fault);
+        return counter = 0;
       }
       extCache[key] = res;
-      if (-- counter === 0)
+      if ((counter -= 2) === 1)
         if (status === 2)
           return run.apply(null, args);
         else
@@ -292,7 +293,7 @@ function run(script, globals, timestamp, deviceData, extensionsCache, startRevis
     });
   }
 
-  if (-- counter === 0)
+  if ((counter -= 2) === 1)
     if (status === 2)
       return run.apply(null, args);
     else
diff --git a/lib/session.coffee b/lib/session.coffee
index 67192c3..0c410c6 100644
--- a/lib/session.coffee
+++ b/lib/session.coffee
@@ -238,7 +238,7 @@ revertDownloadParameters = (sessionData, instance, callback) ->
 timeoutOperations = (sessionData, callback) ->
   faults = []
   operations = []
-  counter = 1
+  counter = 3
 
   for commandKey, operation of sessionData.operations
     if operation.type isnt 'Download'
@@ -259,17 +259,16 @@ timeoutOperations = (sessionData, callback) ->
 
       operations.push(operation)
 
-      ++ counter
+      counter += 2
       revertDownloadParameters(sessionData, operation.args.instance, (err) ->
-        -- counter
-        if err and counter > 0
-          counter = 0
+        if err
+          callback(err) if counter & 1
+          return counter = 0
 
-        return callback(err, faults, operations) if counter == 0
+        return callback(null, faults, operations) if (counter -= 2) == 1
       )
 
-  -- counter
-  return callback(null, faults, operations) if counter == 0
+  return callback(null, faults, operations) if (counter -= 2) == 1
 
 
 addProvisions = (sessionData, channel, provisions) ->
@@ -322,24 +321,21 @@ runProvisions = (sessionData, provisions, startRevision, endRevision, callback)
   done = true
   allDeclarations = []
   allClear = []
-  counter = 1
+  counter = 3
   for provision in provisions
     if not sessionData.cache.provisions[provision[0]]?
       if defaultProvisions[provision[0]]
         done = defaultProvisions[provision[0]](sessionData, provision, allDeclarations, startRevision, endRevision) and done
       continue
 
-    ++ counter
+    counter += 2
     sandbox.run(sessionData.cache.provisions[provision[0]].script,
       {args: provision[1]}, sessionData.timestamp, sessionData.deviceData,
       sessionData.extensionsCache, startRevision, endRevision,
       (err, _fault, _clear, _declarations, _done) ->
-        -- counter
         if err or _fault
-          if counter >= 0
-            counter = 0
-            return callback(err, _fault)
-          return
+          callback(err, _fault) if counter & 1
+          return counter = 0
 
         done &&= _done
 
@@ -349,11 +345,11 @@ runProvisions = (sessionData, provisions, startRevision, endRevision, callback)
         if _clear
           allClear = allClear.concat(_clear)
 
-        if counter == 0
+        if (counter -= 2) == 1
           return callback(null, null, done, allDeclarations, allClear)
       )
 
-  if -- counter == 0
+  if (counter -= 2) == 1
     return callback(null, null, done, allDeclarations, allClear)
 
 
@@ -362,20 +358,17 @@ runVirtualParameters = (sessionData, provisions, startRevision, endRevision, cal
   virtualParameterUpdates = []
   allDeclarations = []
   allClear = []
-  counter = 1
+  counter = 3
   for provision in provisions
-    ++ counter
+    counter += 2
     globals = {TIMESTAMPS: provision[1], VALUES: provision[2]}
     sandbox.run(sessionData.cache.virtualParameters[provision[0]].script, globals,
       sessionData.timestamp, sessionData.deviceData,
       sessionData.extensionsCache, startRevision, endRevision,
       (err, _fault, _clear, _declarations, _done, _returnValue) ->
-        -- counter
         if err or _fault
-          if counter >= 0
-            counter = 0
-            return callback(err, _fault)
-          return
+          callback(err, _fault) if counter & 1
+          return counter = 0
 
         done &&= _done
 
@@ -388,7 +381,7 @@ runVirtualParameters = (sessionData, provisions, startRevision, endRevision, cal
         if _done
           virtualParameterUpdates.push(_returnValue)
 
-        if counter == 0
+        if (counter -= 2) == 1
           toClear = null
           if virtualParameterUpdates.length == provisions.length
             for vpu, i in virtualParameterUpdates
@@ -399,7 +392,7 @@ runVirtualParameters = (sessionData, provisions, startRevision, endRevision, cal
           )
       )
 
-  if -- counter == 0
+  if (counter -= 2) == 1
     toClear = null
     if virtualParameterUpdates.length == provisions.length
       for vpu, i in virtualParameterUpdates
@@ -1566,38 +1559,46 @@ serialize = (sessionData, callback) ->
 
 
 end = (sessionData, callback) ->
-  counter = 2
+  counter = 3
+
+  counter += 2
   db.saveDevice(sessionData.deviceId, sessionData.deviceData, sessionData.new, (err) ->
-    -- counter
-    if err and counter > 0
-      counter = 0
-    return callback(err, sessionData.new) if counter == 0
+    if err
+      callback(err) if counter & 1
+      return counter = 0
+
+    return callback(null, sessionData.new) if (counter -= 2) == 1
   )
 
+  counter += 2
   db.redisClient.del("session_#{sessionData.id}", (err) ->
-    -- counter
-    if err and counter > 0
-      counter = 0
-    return callback(err, sessionData.new) if counter == 0
+    if err
+      callback(err) if counter & 1
+      return counter = 0
+
+    return callback(null, sessionData.new) if (counter -= 2) == 1
   )
 
   for k of sessionData.operationsTouched
-    ++ counter
+    counter += 2
     if sessionData.operations[k]?
       db.saveOperation(sessionData.deviceId, k, sessionData.operations[k], (err) ->
-        -- counter
-        if err and counter > 0
-          counter = 0
-        return callback(err, sessionData.new) if counter == 0
+        if err
+          callback(err) if counter & 1
+          return counter = 0
+
+        return callback(null, sessionData.new) if (counter -= 2) == 1
       )
     else
       db.deleteOperation(sessionData.deviceId, k, (err) ->
-        -- counter
-        if err and counter > 0
-          counter = 0
-        return callback(err, sessionData.new) if counter == 0
+        if err
+          callback(err) if counter & 1
+          return counter = 0
+
+        return callback(null, sessionData.new) if (counter -= 2) == 1
       )
 
+  callback(null, sessionData.new) if (counter -= 2) == 1
 
 exports.init = init
 exports.timeoutOperations = timeoutOperations