1207 fix

lib/sapporo_light/sapporo.cpp

@@ -79,6 +79,9 @@ int sapporo::set_j_particle(int cluster_id,
     exit(-1);
   }
 
+  // Skip test particles (massless particles) as they don't contribute to gravity
+  if (mass <= SAPPORO_TEST_PARTICLE_MASS) return 0;
+
     DS  Dmass = (DS){mass, INT_AS_FLOAT(id)};
     map<int,int>::iterator iterator = mapping_from_address_j_to_index_in_update_array.find(address);
     map<int,int>::iterator end = mapping_from_address_j_to_index_in_update_array.end();
@@ -134,6 +137,7 @@ void sapporo::calc_firsthalf(int cluster_id,
   }
 
   if (address_j.size() > 0) {
+    // Since we skip adding test particles, all particles in address_j are massive
     send_j_particles_to_device(device_id);
   }
 
@@ -147,7 +151,9 @@ void sapporo::calc_firsthalf(int cluster_id,
     acc_j.clear();
     jrk_j.clear();
   }
-  evaluate_gravity(ni, nj);
+  if (nj > 0) {
+    evaluate_gravity(ni, nj);
+  }
 
 }
 

lib/sapporo_light/sapporo.h

@@ -22,6 +22,15 @@
 #include <map>
 
 #include <math.h>
+
+#ifndef SAPPORO_TEST_PARTICLE_MASS
+# if defined(_TINY_)
+#   define SAPPORO_TEST_PARTICLE_MASS ((float)(_TINY_))
+# else
+#   define SAPPORO_TEST_PARTICLE_MASS 1e-30f
+# endif
+#endif
+
 using namespace std;
 
 #include <cuda_runtime.h>

lib/sapporo_light/send_fetch_data.cpp

@@ -111,6 +111,7 @@ int sapporo::fetch_ngb_list_from_device(int ignore) {
 
 
 double sapporo::evaluate_gravity(int ni, int nj) {
+
 #ifdef NGB
     bool ngb = true;
 #else

src/amuse_ph4/src/jdata.cc

@@ -139,6 +139,14 @@ int jdata::add_particle(real pmass, real pradius,
 			real dt)		// default = -1
 {
     const char *in_function = "jdata::add_particle";
+
+    if (pmass <= _TINY_) {
+        if (mpi_rank == 0) {
+            cerr << "Warning: ignoring particle with mass="
+                 << pmass << endl;
+        }
+        return -1;
+    }
     if (DEBUG > 2 && mpi_rank == 0) PRL(in_function);
 
     if (nj >= njbuf) {