USER-DPD: Make fix_shardlow request its own SSA-specific neighbor list,

instead of having pair_dpd_fdt* make the SSA-neighbor list request for it.
Forces an "extra" list to be built, but now skip lists work properly.
Maybe we can detect if skip lists won't be used, and squash the extra list.

src/USER-DPD/fix_shardlow.cpp

@@ -47,6 +47,7 @@
 #include "comm.h"
 #include "neighbor.h"
 #include "neigh_list.h"
+#include "neigh_request.h"
 #include "random_mars.h"
 #include "memory.h"
 #include "domain.h"
@@ -139,6 +140,23 @@ int FixShardlow::setmask()
 
 /* ---------------------------------------------------------------------- */
 
+void FixShardlow::init()
+{
+  int irequest = neighbor->request(this,instance_me);
+  neighbor->requests[irequest]->pair = 0;
+  neighbor->requests[irequest]->fix  = 1;
+  neighbor->requests[irequest]->ssa  = 1;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixShardlow::init_list(int id, NeighList *ptr)
+{
+  list = ptr;
+}
+
+/* ---------------------------------------------------------------------- */
+
 void FixShardlow::pre_exchange()
 {
   memset(atom->ssaAIR, 0, sizeof(int)*atom->nlocal);
@@ -410,7 +428,6 @@ void FixShardlow::initial_integrate(int vflag)
   int nghost = atom->nghost;
 
   int airnum;
-  class NeighList *list; // points to list in pairDPD or pairDPDE
   class RanMars *pRNG;
 
   // NOTE: this logic is specific to orthogonal boxes, not triclinic
@@ -431,12 +448,10 @@ void FixShardlow::initial_integrate(int vflag)
   // Allocate memory for v_t0 to hold the initial velocities for the ghosts
   v_t0 = (double (*)[3]) memory->smalloc(sizeof(double)*3*nghost, "FixShardlow:v_t0");
 
-  // Define pointers to access the neighbor list and RNG
+  // Define pointers to access the RNG
   if(pairDPDE){
-    list = pairDPDE->list;
     pRNG = pairDPDE->random;
   } else {
-    list = pairDPD->list;
     pRNG = pairDPD->random;
   }
   inum = list->inum;

src/USER-DPD/fix_shardlow.h

@@ -26,9 +26,13 @@ namespace LAMMPS_NS {
 
 class FixShardlow : public Fix {
  public:
+  class NeighList *list; // The SSA specific neighbor list
+
   FixShardlow(class LAMMPS *, int, char **);
   ~FixShardlow();
   int setmask();
+  virtual void init();
+  virtual void init_list(int, class NeighList *);
   virtual void setup(int);
   virtual void initial_integrate(int);
   void setup_pre_exchange();

src/USER-DPD/pair_dpd_fdt.cpp

@@ -320,11 +320,9 @@ void PairDPDfdt::init_style()
 
   splitFDT_flag = false;
   int irequest = neighbor->request(this,instance_me);
-  neighbor->requests[irequest]->ssa = 0;
   for (int i = 0; i < modify->nfix; i++)
     if (strcmp(modify->fix[i]->style,"shardlow") == 0){
       splitFDT_flag = true;
-      neighbor->requests[irequest]->ssa = 1;
     }
 }
 

src/USER-DPD/pair_dpd_fdt_energy.cpp

@@ -408,11 +408,9 @@ void PairDPDfdtEnergy::init_style()
 
   splitFDT_flag = false;
   int irequest = neighbor->request(this,instance_me);
-  neighbor->requests[irequest]->ssa = 0;
   for (int i = 0; i < modify->nfix; i++)
     if (strcmp(modify->fix[i]->style,"shardlow") == 0){
       splitFDT_flag = true;
-      neighbor->requests[irequest]->ssa = 1;
     }
 
   bool eos_flag = false;