#611: added documentation for update code that is complex

Author: ppebay

config/synthetic-blocks.yaml

@@ -12,7 +12,7 @@ work_model:
   parameters:
     beta: 0.0
     gamma: 0.0
-    delta: 0.0
+    delta: 0.1
     upper_bounds:
       max_memory_usage: 45.0
 

src/lbaf/Execution/lbsTemperedWithUpdatesCriterion.py

@@ -68,22 +68,26 @@ def compute(self, r_src: Rank, o_src: list, r_dst: Rank, o_dst: Optional[list]=N
 
         # Compute update formulae
         w_max_up = max(
-            self._work_model.update(r_src, o_src, o_dst),
-            self._work_model.update(r_dst, o_dst, o_src))
+            w1 := self._work_model.update(r_src, o_src, o_dst),
+            w2 := self._work_model.update(r_dst, o_dst, o_src))
 
         # Move objects into proposed new arrangement
         self._phase.transfer_objects(r_src, o_src, r_dst, o_dst)
 
         # Compute maximum work of proposed new arrangement
         w_max_new = max(
-            self._work_model.compute(r_src),
-            self._work_model.compute(r_dst))
+            w3 := self._work_model.compute(r_src),
+            w4 := self._work_model.compute(r_dst))
 
         # Move objects back into original arrangement
         self._phase.transfer_objects(r_dst, o_src, r_src, o_dst)
 
-        # Return criterion value
+        # Sanity check
         if w_max_new != w_max_up:
-            self._logger.error(f"Discrepancy in post update works: {w_max_new} <> {m_max_up}")
+            self._logger.error(f"Discrepancy in post update works: {w_max_new} <> {w_max_up}")
+            print(w1, w3)
+            print(w2, w4)
+            raise SystemExit(1)
 
+        # Return criterion value
         return w_max_0 - w_max_new

src/lbaf/Model/lbsAffineCombinationWorkModel.py

@@ -113,16 +113,72 @@ def compute(self, rank: Rank):
 
     def __update_load(self, rank: Rank, o_snd: list, o_rcv: list):
         """Update total load if objects are to be sent and received."""
-        return rank.get_load() + sum(
-            o.get_load() for o in o_rcv) - sum(
-                o.get_load() for o in o_snd)
+        return rank.get_load() - sum(
+            o.get_load() for o in o_snd) + sum(
+                o.get_load() for o in o_rcv)
+
+    def __update_homing(self, rank: Rank, o_snd: list, o_rcv: list):
+        """Update homing costs if objects are to be sent and received."""
+
+        # Keep track of rank id and objects
+        r_id = rank.get_id()
+        r_obj = rank.get_objects().copy()
+
+        # Retrieve current homing cost
+        homing = rank.get_homing()
+
+        # Iterate over all sent objects
+        for o in o_snd:
+            # Update set of blocks on rank
+            r_obj.discard(o)
+
+            # Skip locally homed blocks
+            b = o.get_shared_block()
+            if b.get_home_id() == r_id:
+                continue
+
+            # Determine set of removed non-homed blocks
+            S = set({b})
+            for o_oth in r_obj:
+                if o_oth.get_shared_block() == b:
+                    S = set()
+                    break
+
+            # Update homing cost
+            for b in S:
+                homing -= b.get_size()
+
+        # Iterate over all received objects
+        for o in o_rcv:
+            # Skip locally homed blocks
+            b = o.get_shared_block()
+            if b.get_home_id() == r_id:
+                continue
+
+            # Determine set of added non-homed blocks
+            S = set({b})
+            for o_oth in r_obj:
+                if o_oth.get_shared_block() == b:
+                    S = set()
+                    break
+
+            # Update homing cost
+            for b in S:
+                homing += b.get_size()
+
+            # Update set of blocks on rank
+            r_obj.add(o)
+
+        # Return updated value
+        return homing
 
     def update(self, rank: Rank, o_snd: list, o_rcv: list):
         """Update work if objects are to be sent and received."""
+
         # Return combination of load and volumes
         return self.affine_combination(
             rank.get_alpha(),
             self.__update_load(rank, o_snd, o_rcv),
             rank.get_received_volume(),
             rank.get_sent_volume(),
-            rank.get_homing())
+            self.__update_homing(rank, o_snd, o_rcv))