#501: simplify code and add step modifying pending_steal bool

src/lbaf/Execution/lbsWorkStealingAlgorithm.py

@@ -84,34 +84,32 @@ def run(self):
                 else:
                     self.__logger.info(f"Received some other datatype: {type(item)}")
 
-            # If no work available, request a steal from a random rank
+            # If no work is available, try to request a steal from a random rank
+            elif not self.pending_steal_request:
+                target_rank_id = random.randrange(0, self.algorithm.num_ranks)
+                requesting_rank = self.rank
+                target_rank = self.algorithm.ranks[target_rank_id]
+                if self.algorithm.has_work(target_rank):
+                    steal_request = StealRequest(requesting_rank, target_rank)
+                    # Place steal request in target's queue
+                    self.algorithm.rank_queues[target_rank_id].appendleft(steal_request)
+                    self.pending_steal_request = True
+                    yield self.env.timeout(self.algorithm.steal_time) # double counting steal time here
+
             else:
+                # this rank is awaiting the fulfillment of a steal request
+                # and can not proceed until it gets a response
+                pass
 
-                if not self.pending_steal_request:
-                    target_rank_id = random.randrange(0, self.algorithm.num_ranks)
-                    requesting_rank = self.rank
-                    target_rank = self.algorithm.ranks[target_rank_id]
-                    if self.algorithm.has_work(target_rank):
-                        steal_request = StealRequest(requesting_rank, target_rank)
-                        # Place steal request in target's queue
-                        self.algorithm.rank_queues[target_rank_id].appendleft(steal_request)
-                        yield self.env.timeout(self.algorithm.steal_time)
-                else:
-                    # this rank is awaiting the fulfillment of a steal request
-                    # and can not proceed until it gets a response
-                    pass
+            # print(self.rank_id)
 
     def __get_total_work(self):
         """Returns the total work on the rank."""
         total_work = 0.
         for item in self.algorithm.rank_queues[self.rank_id]:
-            if isinstance(item, Object):
-                total_work += item.get_load()
-            elif isinstance(item, list):
+            if isinstance(item, list):
                 for o in item:
                     total_work += o.get_load()
-            else:
-                pass
         return total_work
 
     def __has_work(self):
@@ -229,15 +227,11 @@ def __reset(self):
     def __has_stealable_cluster(self, rank):
         """Asserts that a given rank has a stealable cluster."""
         stealable = False
-        # Make sure rank is not empty
-        if self.has_work(rank):
-
-            # Make sure the last item in the queue is a cluster
-            if isinstance(self.rank_queues[rank.get_id()][-1], list):
+        rank_queue = self.rank_queues[rank.get_id()]
 
-                # Make sure that the rank will not then be empty (prevent stealing back and forth)
-                if sum(isinstance(elm, list) for elm in self.rank_queues[rank.get_id()]) > 1:
-                    stealable = True
+        # Make sure rank has at least two clusters in its queue (requiring two clusters prevents passing the last cluster around forever)
+        if self.has_work(rank) and isinstance(rank_queue[-1], list) and sum(isinstance(elm, list) for elm in rank_queue) > 1:
+            stealable = True
 
         return stealable
 
@@ -256,7 +250,7 @@ def respond_to_steal_request(self, steal_request: StealRequest):
 
             # Perform steal
             cluster = self.rank_queues[r_target.get_id()].pop()
-            print(f"Performing steal of shared block {cluster[0].get_shared_block_id()} (from {r_target.get_id()} to {r_requesting.get_id()})")
+            self.__logger.info(f"    Performing steal of shared block {cluster[0].get_shared_block_id()} (from {r_target.get_id()} to {r_requesting.get_id()})")
             self.rank_queues[r_requesting.get_id()].append(cluster)
             self.__steal_count += 1