STYLE: check tmp with is_reference() or movable(), instead of isTmp()

- missed consistency in a few places.

- return nullptr (with automatic conversion to tmp) on failures
  instead of tmp<....>(nullptr), for cleaner coding.

INT: add support for an 'immovable' tmp pointer

- this idea is from openfoam.org, to allow creation of a tmp that is
  protected from having its memory reclaimed in field operations

ENH: tmp NewImmovable factory method, forwards as immovable/movable

src/OpenFOAM/memory/refPtr/refPtr.H

@@ -63,6 +63,7 @@ class refPtr
         enum refType
         {
             PTR,        //!< A managed pointer (not ref-counted)
+            REF_Types,  //!< Magic value (ptr: less-than, ref: greater than)
             CREF,       //!< A const reference to an object
             REF         //!< A non-const reference to an object
         };
@@ -175,13 +176,13 @@ public:
         bool good() const noexcept { return bool(ptr_); }
 
         //- If the stored/referenced content is const
-        bool is_const() const noexcept { return (type_ == CREF); }
+        inline bool is_const() const noexcept;
 
         //- True if this is a managed pointer (not a reference)
-        bool is_pointer() const noexcept { return (type_ == PTR); }
+        inline bool is_pointer() const noexcept;
 
         //- True if this is a reference (not a pointer)
-        bool is_reference() const noexcept { return (type_ != PTR); }
+        inline bool is_reference() const noexcept;
 
         //- True if this is a non-null managed pointer
         inline bool movable() const noexcept;

src/OpenFOAM/memory/refPtr/refPtrI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2016-2017 OpenFOAM Foundation
-    Copyright (C) 2018-2022 OpenCFD Ltd.
+    Copyright (C) 2018-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -64,7 +64,6 @@ inline constexpr Foam::refPtr<T>::refPtr(T* p) noexcept
 {}
 
 
-
 template<class T>
 inline constexpr Foam::refPtr<T>::refPtr(const T& obj) noexcept
 :
@@ -190,17 +189,40 @@ inline Foam::refPtr<T>::~refPtr() noexcept
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+template<class T>
+inline bool Foam::refPtr<T>::is_const() const noexcept
+{
+    return (type_ == CREF);
+}
+
+
+template<class T>
+inline bool Foam::refPtr<T>::is_pointer() const noexcept
+{
+    //OR: return (type_ == PTR);
+    return (type_ < REF_Types);
+}
+
+
+template<class T>
+inline bool Foam::refPtr<T>::is_reference() const noexcept
+{
+    //OR: return (type_ == CREF || type_ == REF);
+    return (type_ > REF_Types);
+}
+
+
 template<class T>
 inline bool Foam::refPtr<T>::movable() const noexcept
 {
-    return (is_pointer() && ptr_);
+    return (ptr_ && is_pointer());
 }
 
 
 template<class T>
 inline const T& Foam::refPtr<T>::cref() const
 {
-    if (is_pointer() && !ptr_)
+    if (!ptr_ && is_pointer())
     {
         FatalErrorInFunction
             << this->typeName() << " deallocated"
@@ -221,7 +243,7 @@ inline T& Foam::refPtr<T>::ref() const
             << this->typeName()
             << abort(FatalError);
     }
-    else if (is_pointer() && !ptr_)
+    else if (!ptr_ && is_pointer())
     {
         FatalErrorInFunction
             << this->typeName() << " deallocated"

src/OpenFOAM/memory/tmp/tmp.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2018-2022 OpenCFD Ltd.
+    Copyright (C) 2018-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,6 +34,8 @@ Description
     and a shared_ptr without ref-counting and null deleter.
     This allows the tmp to double as a pointer management and an indirect
     pointer to externally allocated objects.
+    In contrast to std::shared_ptr, only a limited number of tmp items
+    will ever share a pointer.
 
 SourceFiles
     tmpI.H
@@ -73,6 +75,8 @@ class tmp
         enum refType
         {
             PTR,        //!< A managed pointer (ref-counted)
+            CACHE_PTR,  //!< A managed pointer (ref-counted), but immovable
+            REF_Types,  //!< Magic value (ptr: less-than, ref: greater than)
             CREF,       //!< A const reference to an object
             REF         //!< A non-const reference to an object
         };
@@ -86,9 +90,8 @@ class tmp
 
     // Private Member Functions
 
-        //- Increment the ref-count for a managed pointer
+        //- Fatal if ref-count of a managed pointer is oversubscribed
-        //- and check that it is not oversubscribed
+        inline void checkUseCount() const;
-        inline void incrCount();
 
 
 public:
@@ -117,6 +120,10 @@ public:
         //- Construct, taking ownership of the pointer.
         inline explicit tmp(T* p);
 
+        //- Construct, taking ownership of the pointer,
+        //- with specified protection against moving.
+        inline tmp(bool immovable, T* p);
+
         //- Implicit construct for a const reference to an object.
         inline constexpr tmp(const T& obj) noexcept;
 
@@ -166,6 +173,19 @@ public:
             return tmp<T>(new T(std::forward<Args>(args)...));
         }
 
+        //- Construct movable/immovable tmp with forwarding arguments
+        //  \param immovable create as non-movable pointer
+        //  \param args list of arguments with which an instance of T
+        //      will be constructed.
+        //
+        //  \note Similar to std::make_shared, but the overload for
+        //      array types is not disabled.
+        template<class... Args>
+        static tmp<T> NewImmovable(bool immovable, Args&&... args)
+        {
+            return tmp<T>(immovable, new T(std::forward<Args>(args)...));
+        }
+
         //- Construct tmp from derived type with forwarding arguments
         //  \param args list of arguments with which an instance of U
         //      will be constructed.
@@ -191,13 +211,13 @@ public:
         bool good() const noexcept { return bool(ptr_); }
 
         //- If the stored/referenced content is const
-        bool is_const() const noexcept { return (type_ == CREF); }
+        inline bool is_const() const noexcept;
 
         //- True if this is a managed pointer (not a reference)
-        bool is_pointer() const noexcept { return (type_ == PTR); }
+        inline bool is_pointer() const noexcept;
 
         //- True if this is a reference (not a pointer)
-        bool is_reference() const noexcept { return (type_ != PTR); }
+        inline bool is_reference() const noexcept;
 
         //- True if this is a non-null managed pointer with a unique ref-count
         inline bool movable() const noexcept;
@@ -239,9 +259,13 @@ public:
         //- Clear existing and transfer ownership.
         inline void reset(tmp<T>&& other) noexcept;
 
-        //- Delete managed temporary object and set to new given pointer
+        //- Delete managed temporary object and set to new given pointer.
         inline void reset(T* p = nullptr) noexcept;
 
+        //- Delete managed temporary object and set to new given pointer,
+        //- with specified protection against moving.
+        inline void reset(bool immovable, T* p) noexcept;
+
         //- Avoid inadvertent casting (to object or pointer)
         void reset(const autoPtr<T>&) = delete;
 
@@ -330,8 +354,10 @@ public:
         //- Identical to good(), or bool operator
         bool valid() const noexcept { return bool(ptr_); }
 
-        //- Identical to is_pointer()
+        //- Identical to is_pointer(). Prefer is_pointer() or movable().
-        bool isTmp() const noexcept { return type_ == PTR; }
+        //
+        //  \deprecated(2020-07) - prefer is_pointer() or movable()
+        bool isTmp() const noexcept { return is_pointer(); }
 
         //- Deprecated(2020-07) True if a null managed pointer
         //

src/OpenFOAM/memory/tmp/tmpI.H

@@ -29,23 +29,6 @@ License
 #include "error.H"
 #include <typeinfo>
 
-// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
-
-template<class T>
-inline void Foam::tmp<T>::incrCount()
-{
-    ptr_->refCount::operator++();
-
-    if (ptr_->refCount::use_count() > 1)
-    {
-        FatalErrorInFunction
-            << "Attempt to create more than 2 tmp's referring to the same"
-               " object of type tmp<" << typeid(T).name() << '>'
-            << abort(FatalError);
-    }
-}
-
-
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
 template<class T>
@@ -55,6 +38,23 @@ inline Foam::word Foam::tmp<T>::typeName()
 }
 
 
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+template<class T>
+inline void Foam::tmp<T>::checkUseCount() const
+{
+    if (ptr_ && ptr_->refCount::use_count() > 1)
+    {
+        FatalErrorInFunction
+            << "Attempt to create more than "
+            << (ptr_->refCount::use_count() + 1)
+            << " tmp's referring to the same object of type tmp<"
+            << typeid(T).name() << '>'
+            << abort(FatalError);
+    }
+}
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 template<class T>
@@ -90,6 +90,15 @@ inline Foam::tmp<T>::tmp(T* p)
 }
 
 
+template<class T>
+inline Foam::tmp<T>::tmp(bool immovable, T* p)
+:
+    tmp<T>(p)
+{
+    if (ptr_ && immovable) type_ = CACHE_PTR;
+}
+
+
 template<class T>
 inline constexpr Foam::tmp<T>::tmp(const T& obj) noexcept
 :
@@ -130,7 +139,8 @@ inline Foam::tmp<T>::tmp(const tmp<T>& rhs)
     {
         if (ptr_)
         {
-            this->incrCount();
+            ptr_->refCount::operator++();
+            this->checkUseCount();
         }
         else
         {
@@ -160,7 +170,8 @@ inline Foam::tmp<T>::tmp(const tmp<T>& rhs, bool reuse)
             }
             else
             {
-                this->incrCount();
+                ptr_->refCount::operator++();
+                this->checkUseCount();
             }
         }
         else
@@ -192,17 +203,40 @@ inline Foam::tmp<T>::~tmp() noexcept
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+template<class T>
+inline bool Foam::tmp<T>::is_const() const noexcept
+{
+    return (type_ == CREF);
+}
+
+
+template<class T>
+inline bool Foam::tmp<T>::is_pointer() const noexcept
+{
+    //OR: return (type_ == PTR || type_ == CACHE_PTR);
+    return (type_ < REF_Types);
+}
+
+
+template<class T>
+inline bool Foam::tmp<T>::is_reference() const noexcept
+{
+    //OR: return (type_ == CREF || type_ == REF);
+    return (type_ > REF_Types);
+}
+
+
 template<class T>
 inline bool Foam::tmp<T>::movable() const noexcept
 {
-    return (is_pointer() && ptr_ && ptr_->refCount::unique());
+    return (ptr_ && type_ == PTR && ptr_->refCount::unique());
 }
 
 
 template<class T>
 inline const T& Foam::tmp<T>::cref() const
 {
-    if (is_pointer() && !ptr_)
+    if (!ptr_ && is_pointer())
     {
         FatalErrorInFunction
             << this->typeName() << " deallocated"
@@ -223,7 +257,7 @@ inline T& Foam::tmp<T>::ref() const
             << this->typeName()
             << abort(FatalError);
     }
-    else if (is_pointer() && !ptr_)
+    else if (!ptr_ && is_pointer())
     {
         FatalErrorInFunction
             << this->typeName() << " deallocated"
@@ -244,7 +278,7 @@ inline T* Foam::tmp<T>::ptr() const
             << abort(FatalError);
     }
 
-    if (is_pointer())
+    if (type_ == PTR)
     {
         if (!ptr_->refCount::unique())
         {
@@ -262,6 +296,7 @@ inline T* Foam::tmp<T>::ptr() const
         return p;
     }
 
+    // CACHE_PTR (immovable) is cloned, as per a reference
     return ptr_->clone().ptr();
 }
 
@@ -269,7 +304,7 @@ inline T* Foam::tmp<T>::ptr() const
 template<class T>
 inline void Foam::tmp<T>::clear() const noexcept
 {
-    if (is_pointer() && ptr_)
+    if (ptr_ && is_pointer())
     {
         if (ptr_->refCount::unique())
         {
@@ -293,6 +328,14 @@ inline void Foam::tmp<T>::reset(T* p) noexcept
 }
 
 
+template<class T>
+inline void Foam::tmp<T>::reset(bool immovable, T* p) noexcept
+{
+    reset(p);
+    if (ptr_ && immovable) type_ = CACHE_PTR;
+}
+
+
 template<class T>
 inline void Foam::tmp<T>::reset(tmp<T>&& other) noexcept
 {
@@ -382,7 +425,7 @@ inline void Foam::tmp<T>::swap(tmp<T>& other) noexcept
 template<class T>
 inline const T* Foam::tmp<T>::operator->() const
 {
-    if (is_pointer() && !ptr_)
+    if (!ptr_ && is_pointer())
     {
         FatalErrorInFunction
             << this->typeName() << " deallocated"
@@ -403,7 +446,7 @@ inline T* Foam::tmp<T>::operator->()
             << this->typeName()
             << abort(FatalError);
     }
-    else if (is_pointer() && !ptr_)
+    else if (!ptr_ && is_pointer())
     {
         FatalErrorInFunction
             << this->typeName() << " deallocated"
@@ -428,7 +471,7 @@ inline void Foam::tmp<T>::operator=(const tmp<T>& other)
     if (other.is_pointer())
     {
         ptr_ = other.ptr_;
-        type_ = PTR;
+        type_ = other.type_;
 
         other.ptr_ = nullptr;
         other.type_ = PTR;

src/atmosphericModels/fvOptions/atmAmbientTurbSource/atmAmbientTurbSource.C

@@ -134,8 +134,7 @@ Foam::fv::atmAmbientTurbSource::atmAmbientTurbSource
     else
     {
         FatalErrorInFunction
-            << "Unable to find neither epsilon nor omega field." << nl
+            << "Needs either epsilon or omega field."
-            << "atmAmbientTurbSource needs either epsilon or omega field."
             << abort(FatalError);
     }
 

src/atmosphericModels/fvOptions/atmBuoyancyTurbSource/atmBuoyancyTurbSource.C

@@ -226,8 +226,7 @@ Foam::fv::atmBuoyancyTurbSource::atmBuoyancyTurbSource
     else
     {
         FatalErrorInFunction
-            << "Unable to find neither epsilon nor omega field." << nl
+            << "Needs either epsilon or omega field."
-            << "atmBuoyancyTurbSource needs either epsilon or omega field."
             << abort(FatalError);
     }
 

src/atmosphericModels/fvOptions/atmLengthScaleTurbSource/atmLengthScaleTurbSource.C

@@ -161,8 +161,7 @@ Foam::fv::atmLengthScaleTurbSource::atmLengthScaleTurbSource
     else
     {
         FatalErrorInFunction
-            << "Unable to find neither epsilon nor omega field." << nl
+            << "Needs either epsilon or omega field."
-            << "atmLengthScaleTurbSource needs either epsilon or omega field."
             << abort(FatalError);
     }
 

src/atmosphericModels/fvOptions/atmPlantCanopyTurbSource/atmPlantCanopyTurbSource.C

@@ -123,8 +123,9 @@ Foam::fv::atmPlantCanopyTurbSource::atmPlantCanopyTurbSource
     tmp<volScalarField> tepsilon = turbPtr->epsilon();
     tmp<volScalarField> tomega = turbPtr->omega();
 
-    if (!tepsilon.isTmp())
+    if (tepsilon.is_reference())
     {
+        isEpsilon_ = true;
         fieldNames_[0] = tepsilon().name();
 
         const dictionary& turbDict = turbPtr->coeffDict();
@@ -132,7 +133,7 @@ Foam::fv::atmPlantCanopyTurbSource::atmPlantCanopyTurbSource
         C1_.read("C1", turbDict);
         C2_.read("C2", turbDict);
     }
-    else if (!tomega.isTmp())
+    else if (tomega.is_reference())
     {
         isEpsilon_ = false;
         fieldNames_[0] = tomega().name();
@@ -143,8 +144,7 @@ Foam::fv::atmPlantCanopyTurbSource::atmPlantCanopyTurbSource
     else
     {
         FatalErrorInFunction
-            << "Unable to find neither epsilon nor omega field." << nl
+            << "Needs either epsilon or omega field."
-            << "atmPlantCanopyTurbSource needs either epsilon or omega field."
             << abort(FatalError);
     }
 

src/finiteArea/finiteArea/lnGradSchemes/uncorrectedLnGrad/uncorrectedLnGrad.C

@@ -49,7 +49,7 @@ uncorrectedLnGrad<Type>::correction
 ) const
 {
     NotImplemented;
-    return tmp<GeometricField<Type, faePatchField, edgeMesh>>(nullptr);
+    return nullptr;
 }
 
 

src/finiteVolume/cfdTools/general/constrainHbyA/constrainHbyA.C

@@ -40,18 +40,18 @@ Foam::tmp<Foam::volVectorField> Foam::constrainHbyA
 {
     tmp<volVectorField> tHbyANew;
 
-    if (tHbyA.isTmp())
+    if (tHbyA.movable())
     {
         tHbyANew = tHbyA;
         tHbyANew.ref().rename("HbyA");
     }
     else
     {
-        tHbyANew = new volVectorField("HbyA", tHbyA);
+        // Clone and use given name
+        tHbyANew.reset(new volVectorField("HbyA", tHbyA));
     }
 
-    volVectorField& HbyA = tHbyANew.ref();
+    auto& HbyAbf = tHbyANew.ref().boundaryFieldRef();
-    volVectorField::Boundary& HbyAbf = HbyA.boundaryFieldRef();
 
     forAll(U.boundaryField(), patchi)
     {

src/finiteVolume/finiteVolume/snGradSchemes/orthogonalSnGrad/orthogonalSnGrad.C

@@ -50,7 +50,7 @@ orthogonalSnGrad<Type>::correction
 ) const
 {
     NotImplemented;
-    return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>(nullptr);
+    return nullptr;
 }
 
 

src/finiteVolume/finiteVolume/snGradSchemes/snGradScheme/snGradScheme.H

@@ -172,15 +172,11 @@ public:
             return false;
         }
 
-        //- Return the explicit correction to the snGrad
+        //- Return the explicit correction to the snGrad for the given field
-        //- for the given field
         virtual tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
         correction(const GeometricField<Type, fvPatchField, volMesh>&) const
         {
-            return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+            return nullptr;
-            (
-                nullptr
-            );
         }
 
         //- Return the snGrad of the given cell field

src/finiteVolume/finiteVolume/snGradSchemes/uncorrectedSnGrad/uncorrectedSnGrad.C

@@ -50,7 +50,7 @@ uncorrectedSnGrad<Type>::correction
 ) const
 {
     NotImplemented;
-    return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>(nullptr);
+    return nullptr;
 }
 
 

src/finiteVolume/interpolation/surfaceInterpolation/schemes/CoBlended/CoBlended.H

@@ -315,10 +315,7 @@ public:
             }
             else
             {
-                return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+                return nullptr;
-                (
-                    nullptr
-                );
             }
         }
 };

src/finiteVolume/interpolation/surfaceInterpolation/schemes/cellCoBlended/cellCoBlended.H

@@ -342,10 +342,7 @@ public:
             }
             else
             {
-                return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+                return nullptr;
-                (
-                    nullptr
-                );
             }
         }
 };

src/finiteVolume/interpolation/surfaceInterpolation/schemes/fixedBlended/fixedBlended.H

@@ -242,10 +242,7 @@ public:
             }
             else
             {
-                return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+                return nullptr;
-                (
-                    nullptr
-                );
             }
         }
 

src/finiteVolume/interpolation/surfaceInterpolation/schemes/limiterBlended/limiterBlended.H

@@ -222,10 +222,7 @@ public:
             }
             else
             {
-                return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+                return nullptr;
-                (
-                    nullptr
-                );
             }
         }
 };

src/finiteVolume/interpolation/surfaceInterpolation/schemes/localBlended/localBlended.H

@@ -234,10 +234,7 @@ public:
             }
             else
             {
-                return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+                return nullptr;
-                (
-                    nullptr
-                );
             }
         }
 };

src/finiteVolume/interpolation/surfaceInterpolation/schemes/outletStabilised/outletStabilised.H

@@ -238,10 +238,7 @@ public:
             }
             else
             {
-                return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+                return nullptr;
-                (
-                    nullptr
-                );
             }
         }
 };

src/finiteVolume/interpolation/surfaceInterpolation/surfaceInterpolationScheme/surfaceInterpolationScheme.H

@@ -203,10 +203,7 @@ public:
         virtual tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
         correction(const GeometricField<Type, fvPatchField, volMesh>&) const
         {
-            return tmp<GeometricField<Type, fvsPatchField, surfaceMesh>>
+            return nullptr;
-            (
-                nullptr
-            );
         }
 
         //- Return the face-interpolate of the given cell field

src/lagrangian/turbulence/submodels/Kinematic/DispersionModel/DispersionRASModel/DispersionRASModel.C

@@ -98,8 +98,8 @@ Foam::DispersionRASModel<CloudType>::DispersionRASModel
 :
     DispersionModel<CloudType>(owner),
     kPtr_(nullptr),
-    ownK_(false),
     epsilonPtr_(nullptr),
+    ownK_(false),
     ownEpsilon_(false)
 {}
 
@@ -112,8 +112,8 @@ Foam::DispersionRASModel<CloudType>::DispersionRASModel
 :
     DispersionModel<CloudType>(dm),
     kPtr_(dm.kPtr_),
-    ownK_(dm.ownK_),
     epsilonPtr_(dm.epsilonPtr_),
+    ownK_(dm.ownK_),
     ownEpsilon_(dm.ownEpsilon_)
 {
     dm.ownK_ = false;
@@ -138,20 +138,22 @@ void Foam::DispersionRASModel<CloudType>::cacheFields(const bool store)
     if (store)
     {
         tmp<volScalarField> tk = this->kModel();
-        if (tk.isTmp())
+        if (tk.movable())
         {
+            // Take ownership
             kPtr_ = tk.ptr();
             ownK_ = true;
         }
         else
         {
-            kPtr_ = &tk();
+            kPtr_ = &tk.cref();
             ownK_ = false;
         }
 
         tmp<volScalarField> tepsilon = this->epsilonModel();
-        if (tepsilon.isTmp())
+        if (tepsilon.movable())
         {
+            // Take ownership
             epsilonPtr_ = tepsilon.ptr();
             ownEpsilon_ = true;
         }
@@ -163,12 +165,12 @@ void Foam::DispersionRASModel<CloudType>::cacheFields(const bool store)
     }
     else
     {
-        if (ownK_ && kPtr_)
+        if (ownK_)
         {
             deleteDemandDrivenData(kPtr_);
             ownK_ = false;
         }
-        if (ownEpsilon_ && epsilonPtr_)
+        if (ownEpsilon_)
         {
             deleteDemandDrivenData(epsilonPtr_);
             ownEpsilon_ = false;

src/lagrangian/turbulence/submodels/Kinematic/DispersionModel/DispersionRASModel/DispersionRASModel.H

@@ -60,13 +60,13 @@ protected:
             //- Turbulence k
             const volScalarField* kPtr_;
 
-            //- Take ownership of the k field
-            mutable bool ownK_;
-
             //- Turbulence epsilon
             const volScalarField* epsilonPtr_;
 
-            //- Take ownership of the epsilon field
+            //- Local ownership of the k field
+            mutable bool ownK_;
+
+            //- Local ownership of the epsilon field
             mutable bool ownEpsilon_;
 
 

src/lagrangian/turbulence/submodels/Thermodynamic/ParticleForces/BrownianMotion/BrownianMotionForce.C

@@ -77,8 +77,8 @@ Foam::BrownianMotionForce<CloudType>::BrownianMotionForce
     ParticleForce<CloudType>(owner, mesh, dict, typeName, true),
     rndGen_(owner.rndGen()),
     lambda_(this->coeffs().getScalar("lambda")),
-    turbulence_(this->coeffs().getBool("turbulence")),
     kPtr_(nullptr),
+    turbulence_(this->coeffs().getBool("turbulence")),
     ownK_(false)
 {}
 
@@ -92,8 +92,8 @@ Foam::BrownianMotionForce<CloudType>::BrownianMotionForce
     ParticleForce<CloudType>(bmf),
     rndGen_(bmf.rndGen_),
     lambda_(bmf.lambda_),
-    turbulence_(bmf.turbulence_),
     kPtr_(nullptr),
+    turbulence_(bmf.turbulence_),
     ownK_(false)
 {}
 
@@ -102,7 +102,9 @@ Foam::BrownianMotionForce<CloudType>::BrownianMotionForce
 
 template<class CloudType>
 Foam::BrownianMotionForce<CloudType>::~BrownianMotionForce()
-{}
+{
+    cacheFields(false);
+}
 
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
@@ -115,20 +117,21 @@ void Foam::BrownianMotionForce<CloudType>::cacheFields(const bool store)
         if (store)
         {
             tmp<volScalarField> tk = kModel();
-            if (tk.isTmp())
+            if (tk.movable())
             {
+                // Take ownership
                 kPtr_ = tk.ptr();
                 ownK_ = true;
             }
             else
             {
-                kPtr_ = &tk();
+                kPtr_ = &tk.cref();
                 ownK_ = false;
             }
         }
         else
         {
-            if (ownK_ && kPtr_)
+            if (ownK_)
             {
                 deleteDemandDrivenData(kPtr_);
                 ownK_ = false;

src/lagrangian/turbulence/submodels/Thermodynamic/ParticleForces/BrownianMotion/BrownianMotionForce.H

@@ -65,7 +65,7 @@ class BrownianMotionForce
 :
     public ParticleForce<CloudType>
 {
-    // Private data
+    // Private Data
 
         //- Reference to the cloud random number generator
         Random& rndGen_;
@@ -73,13 +73,13 @@ class BrownianMotionForce
         //- Molecular free path length [m]
         const scalar lambda_;
 
-        //- Turbulence flag
-        bool turbulence_;
-
         //- Pointer to the turbulence kinetic energy field
         const volScalarField* kPtr_;
 
-        //- Flag that indicates ownership of turbulence k field
+        //- Turbulence flag
+        bool turbulence_;
+
+        //- Local ownership of the turbulence k field
         bool ownK_;