Added Unit test for nccl send recv (#506)

Added Send Receive test that tests through all pairs

test/common/TestBed.cpp

@@ -220,21 +220,35 @@ namespace RcclUnitTesting
     }
   }
 
-  void TestBed::ExecuteCollectives()
+  void TestBed::ExecuteCollectives(std::vector<int> const &currentRanks)
   {
     int const cmd = TestBedChild::CHILD_EXECUTE_COLL;
     ++TestBed::NumTestsRun();
 
+    std::vector<std::vector<int>> ranksPerChild(this->numActiveChildren);
+    for (int rank = 0; rank < currentRanks.size(); ++rank)
+    {
+      ranksPerChild[rankToChildMap[currentRanks[rank]]].push_back(rank);
+    }
+
     // Send ExecuteColl command to each active child process
     for (int childId = 0; childId < this->numActiveChildren; ++childId)
     {
-      PIPE_WRITE(childId, cmd);
+      if ((currentRanks.size() == 0) || (ranksPerChild[childId].size() > 0))
+      {
+        PIPE_WRITE(childId, cmd);
+        int tempCurrentRanks = currentRanks.size();
+        PIPE_WRITE(childId, tempCurrentRanks);
+        for (int rank = 0; rank < currentRanks.size(); ++rank){
+          PIPE_WRITE(childId, currentRanks[rank]);
+        }
+      }
     }
 
     // Wait for child acknowledgement
     for (int childId = 0; childId < this->numActiveChildren; ++childId)
     {
-      PIPE_CHECK(childId);
+      if ((currentRanks.size() == 0) || (ranksPerChild[childId].size() > 0)) PIPE_CHECK(childId);
     }
   }