Rename variables and update comments

Signed-off-by: Gavin Halliday <[email protected]>

common/workunit/wujobq.cpp

@@ -1747,21 +1747,27 @@ class CJobQueue: public CJobQueueBase, implements IJobQueue
         CriticalBlock block(crit);
         retitem = NULL;
         assertex(connected); // must be connected
-        int curmp = maxp?maxp->get():0;
-        int nextmp = curmp;
+        int prevmp = maxp?maxp->get():0;
+        int curmp = prevmp;
         for (;;) {
             bool timedout = false;
             Owned<IJobQueueItem> item;
             {
                 CriticalUnblock unblock(crit);
                 // this is a bit complicated with multi-thor
-                if (prioritytransitiondelay||maxp) {
-                    item.setown(dodequeue((std::max(curmp,nextmp)/10)*10, // round down to multiple of 10
-                        prioritytransitiondelay?prioritytransitiondelay:60000,prioritytransitiondelay>0,&timedout));
+                if (prioritytransitiondelay||maxp)
+                {
+                    int itemmax = (std::max(prevmp,curmp)/10)*10;    // round down to multiple of 10
+                    unsigned timeout = prioritytransitiondelay?prioritytransitiondelay:60000;
                                                             // if dynamic priority check every minute
-                    if (!prioritytransitiondelay) {
-                        curmp = nextmp; // using max above is a bit devious to allow transition
-                        nextmp = maxp->get();
+                    bool usePrevPrio = prioritytransitiondelay>0;
+                    item.setown(dodequeue(itemmax, timeout, usePrevPrio, &timedout));
+
+                    //If not waiting for a transition, then update the minimum priroty that is acceptable
+                    if (!prioritytransitiondelay)
+                    {
+                        prevmp = curmp; // using max above is a bit devious to allow transition
+                        curmp = maxp->get();
                     }
                 }
                 else

common/workunit/wujobq.hpp

@@ -30,9 +30,30 @@
  * If a position is given, then the priority may be adjusted to ensure it is consistent with the items before it and after it in the queue
  *
  * When an item is dequeued, the head of the queue is removed.
- * - There is an option, currently used in thor, to say wait for up to 30 seconds if the priority at the header of the queue is lower
- *   than the last item dequeued from that queue.  I think this is to ensure that high priority workunits get precedence even if there
- *   are  short pauses between graphs.  However, this will prevent all thor instances from dequeuing for that period.
+ *
+ * There is an option in acceptConversatin(), currently used in thor, to say wait for up to 30 seconds if the priority at the header of the queue is lower
+ * than the last item dequeued from that queue.  I think this is to ensure that high priority workunits get precedence even if there
+ * are  short pauses between graphs.  However, this will prevent all thor instances for the same queue from dequeuing for that period.
+ *
+ * NOTE: If this logic is included I think this should really be the priority of the last item THIS thor dequeued.
+ *
+ * After 30 seconds has passed it will only dequeue items with a higher priority than the maximum priority currently being processed
+ * by a thor instance reading from that queue.  I think that means that if there is a thor instance processing a high priority workunit
+ * no lower priority workunits will be selected.
+ *
+ * NOTE: I don't understand this logic.
+ *
+ *
+ * We want to add the following semantics:
+ *
+ * When a server requests to dequeue an item it can pass a worker priority.
+ * - If there is an item on the queue, then dequeue it
+ * - Otherwise record the worker priority in the Client information.  (If there are multiple threads do they have to have the same priority??)
+ * - When an item is received, the WAITING worker with the highest priority gets to process it.
+ *
+ * Problems:
+ *   Multiple threads from a single client
+ *   Ensuring there are no race conditions
  *
  */
 interface IJobQueueItem: extends serializable