continuing population control work

src/Particle/Walker.h

@@ -411,6 +411,8 @@ struct Walker
    */
   inline size_t byteSize()
   {
+    // TODO: fix this! this is a non intuitive side effect for a size call
+    //       breaks a bunch of things that could be const
     if (!DataSet.size())
     {
       registerData();

src/QMCDrivers/DMC/WalkerControlMPI.cpp

@@ -513,8 +513,8 @@ void WalkerControlMPI::swapWalkersSimple(MCPopulation& pop, PopulationAdjustment
       ++messages_incoming;
       if ( adjust.bad_walkers.size() > 0)
       {
-        pop.kill_walker(adjust.bad_walkers.back());
-        adjust.bad_walkers.pop();
+        pop.killWalker(adjust.bad_walkers.back());
+        adjust.bad_walkers.pop_back();
       }
     }
             
@@ -550,7 +550,7 @@ void WalkerControlMPI::swapWalkersSimple(MCPopulation& pop, PopulationAdjustment
   messages_incoming *= 2; // extra message sent for multiplicity
   if( messages_incoming > 0)
   {
-    for( int im = 0 ; im < messasges_incoming; ++im)
+    for( int im = 0 ; im < messages_incoming; ++im)
     {
       WalkerMessage message(pop.spawnWalker(), MyContext);
       receive_requests.push_back(myComm->comm.ireceive_value(message.multiplicity));

src/QMCDrivers/DMC/WalkerControlMPI.h

@@ -26,12 +26,12 @@ class WalkerControlMPITest;
 
 struct WalkerMessage
 {
-  const WalkerControlBase::MCPWalker& walker;
+  WalkerControlBase::MCPWalker& walker;
   // i.e. MPI rank
   const int target_rank;
   int multiplicity = 1;
   size_t byteSize = 0;
-  WalkerMessage(const WalkerControlBase::MCPWalker& walk, const int target) : walker(walk), target_rank(target){};
+  WalkerMessage(WalkerControlBase::MCPWalker& walk, const int target) : walker(walk), target_rank(target){};
 };
 
 bool operator==(const WalkerMessage& A, const WalkerMessage& B)

src/QMCDrivers/MCPopulation.cpp

@@ -142,18 +142,30 @@ void MCPopulation::createWalkers(IndexType num_walkers)
 
 /** creates a walker and returns a reference
  */
-MCPopulation::MCPWalker& MCPopulation::spawnWalker(const MCPWalker& walker)
+MCPopulation::MCPWalker& MCPopulation::spawnWalker()
 {
   auto it_walkers = walkers_.begin();
+  int walker_index;
   while (it_walkers != walkers_.end())
   {
     if (*it_walkers == nullptr)
-      
+    {
+      createWalkerInplace(*it_walkers);
+      allocateWalkerStuffInplace(walker_index);
+      break;
+    }
+    ++walker_index;
+  }
+  // you need to add to all the vectors if no walkers have been killed
+  // for now we throw since this must be implemented
+  if (walker_index == walkers_.size())
+    throw std::runtime_error("Needed to add to population in MCPopulation but it is not implemented.");
+  return **it_walkers;
 }
 
 /** Kill a walker
  */
-void MCPopulation::killWalker(const MCPWalker& walker)
+void MCPopulation::killWalker(MCPWalker& walker)
 {
   // find the walker and null its pointer in the walker vector
   auto it_walkers = walkers_.begin();

src/QMCDrivers/MCPopulation.h

@@ -107,6 +107,7 @@ public:
   MCPWalker& spawnWalker();
   void killWalker(MCPWalker&);
   void createWalkerInplace(UPtr<MCPWalker>& walker_ptr);
+  void allocateWalkerStuffInplace(int walker_index);
   /** }@ */
 
   void createWalkers();