Reducing overhead when no collisions are present

Particles are added to lists only if there are MCC collisions. Hopefully
this will reduce overhead when OpenMP is used and no collisions are
active.

src/modules/solver/moduleSolver.f90

@@ -43,14 +43,14 @@ MODULE moduleSolver
     END SUBROUTINE solveEM_interface
 
     !Apply nonAnalogue scheme to a particle
-    SUBROUTINE weightingScheme_interface(part, volOld, volNew)
+    SUBROUTINE weightingScheme_interface(part, cellOld, cellNew)
       USE moduleSpecies
       USE moduleMesh
       IMPLICIT NONE
 
       TYPE(particle), INTENT(inout):: part
-      CLASS(meshCell), POINTER, INTENT(in):: volOld
-      CLASS(meshCell), POINTER, INTENT(inout):: volNew
+      CLASS(meshCell), POINTER, INTENT(in):: cellOld
+      CLASS(meshCell), POINTER, INTENT(inout):: cellNew
 
     END SUBROUTINE weightingScheme_interface
 
@@ -322,31 +322,37 @@ MODULE moduleSolver
 
       !$OMP SECTION
       !Erase the list of particles inside the cell if particles have been pushed
-      DO s = 1, nSpecies
-        DO e = 1, mesh%numCells
-          IF (solver%pusher(s)%pushSpecies) THEN 
-            CALL mesh%cells(e)%obj%listPart_in(s)%erase()
-            mesh%cells(e)%obj%totalWeight(s) = 0.D0
+      IF (doMCC) THEN
+        DO s = 1, nSpecies
+          DO e = 1, mesh%numCells
+            IF (solver%pusher(s)%pushSpecies) THEN 
+              CALL mesh%cells(e)%obj%listPart_in(s)%erase()
+              mesh%cells(e)%obj%totalWeight(s) = 0.D0
 
-          END IF
+            END IF
+
+          END DO
 
         END DO
 
-      END DO
+      END IF
 
       !$OMP SECTION
       !Erase the list of particles inside the cell in coll mesh
-      DO s = 1, nSpecies
-        DO e = 1, meshColl%numCells
-          IF (solver%pusher(s)%pushSpecies) THEN 
-            CALL meshColl%cells(e)%obj%listPart_in(s)%erase()
-            meshColl%cells(e)%obj%totalWeight(s) = 0.D0
+      IF (doubleMesh) THEN
+        DO s = 1, nSpecies
+          DO e = 1, meshColl%numCells
+            IF (solver%pusher(s)%pushSpecies) THEN 
+              CALL meshColl%cells(e)%obj%listPart_in(s)%erase()
+              meshColl%cells(e)%obj%totalWeight(s) = 0.D0
 
-          END IF
+            END IF
+
+          END DO
 
         END DO
-
-      END DO
+      
+      END IF
 
       !$OMP END SECTIONS
 
@@ -368,7 +374,7 @@ MODULE moduleSolver
       !Loops over the particles to scatter them
       !$OMP DO
       DO n = 1, nPartOld
-        cell => mesh%cells(partOld(n)%vol)%obj
+        cell => mesh%cells(partOld(n)%cell)%obj
         CALL cell%scatter(cell%nNodes, partOld(n))
 
       END DO
@@ -387,28 +393,28 @@ MODULE moduleSolver
     END SUBROUTINE doEMField
 
     !Split particles as a function of cell volume and splits particle
-    SUBROUTINE volumeWScheme(part, volOld, volNew)
+    SUBROUTINE volumeWScheme(part, cellOld, cellNew)
       USE moduleSpecies
       USE moduleMesh
       USE moduleRandom
       IMPLICIT NONE
 
       TYPE(particle), INTENT(inout):: part
-      CLASS(meshCell), POINTER, INTENT(in):: volOld
-      CLASS(meshCell), POINTER, INTENT(inout):: volNew
+      CLASS(meshCell), POINTER, INTENT(in):: cellOld
+      CLASS(meshCell), POINTER, INTENT(inout):: cellNew
       REAL(8):: fractionVolume, pSplit
 
       !If particle changes volume to smaller cell
-      IF (volOld%volume > volNew%volume .AND. &
+      IF (cellOld%volume > cellNew%volume .AND. &
           part%weight >= part%species%weight*1.0D-1) THEN
-        fractionVolume = volOld%volume/volNew%volume
+        fractionVolume = cellOld%volume/cellNew%volume
 
         !Calculate probability of splitting particle
         pSplit = 1.D0 - DEXP(-fractionVolume*1.0D-1)
 
         IF (random() < pSplit) THEN
           !Split particle in two
-          CALL splitParticle(part, 2, volNew)
+          CALL splitParticle(part, 2, cellNew)
 
         END IF
 
@@ -418,7 +424,7 @@ MODULE moduleSolver
 
     !Subroutine to split the particle 'part' into a number 'nSplit' of particles.
     !'nSplit-1' particles are added to the partNAScheme list
-    SUBROUTINE splitParticle(part, nSplit, vol)
+    SUBROUTINE splitParticle(part, nSplit, cell)
       USE moduleSpecies
       USE moduleList
       USE moduleMesh
@@ -427,7 +433,7 @@ MODULE moduleSolver
 
       TYPE(particle), INTENT(inout):: part
       INTEGER, INTENT(in):: nSplit
-      CLASS(meshCell), INTENT(inout):: vol
+      CLASS(meshCell), INTENT(inout):: cell
       REAL(8):: newWeight
       TYPE(particle), POINTER:: newPart
       INTEGER:: p
@@ -449,10 +455,13 @@ MODULE moduleSolver
         CALL partWScheme%add(newPart)
         CALL partWScheme%unsetLock()
         !Add particle to cell list
-        CALL OMP_SET_lock(vol%lock)
         sp = part%species%n
-        CALL vol%listPart_in(sp)%add(newPart)
-        CALL OMP_UNSET_lock(vol%lock)
+        IF (doMCC) THEN
+          CALL OMP_SET_lock(cell%lock)
+          CALL cell%listPart_in(sp)%add(newPart)
+          CALL OMP_UNSET_lock(cell%lock)
+
+        END IF
 
       END DO
 
@@ -465,18 +474,18 @@ MODULE moduleSolver
 
       CLASS(solverGeneric), INTENT(in):: self
       TYPE(particle), INTENT(inout):: part
-      CLASS(meshCell), POINTER:: volOld, volNew
+      CLASS(meshCell), POINTER:: cellOld, cellNew
 
       !Assume that particle is outside the domain
       part%n_in = .FALSE.
 
-      volOld => mesh%cells(part%vol)%obj
-      CALL volOld%findCell(part)
+      cellOld => mesh%cells(part%cell)%obj
+      CALL cellOld%findCell(part)
       CALL findCellColl(part)
       !Call the NA shcme
       IF (ASSOCIATED(self%weightingScheme)) THEN
-        volNew => mesh%cells(part%vol)%obj
-        CALL self%weightingScheme(part, volOld, volNew)
+        cellNew => mesh%cells(part%cell)%obj
+        CALL self%weightingScheme(part, cellOld, cellNew)
 
       END IF