ENH: have MUST_READ_IF_MODIFIED on IOdictionary construction

2025-11-28 03:28:01 +00:00 · 2010-06-02 09:48:07 +01:00
parent dd475e3c6b
commit c51a2b0f63
192 changed files with 779 additions and 411 deletions
--- a/117
+++ b/117
@ -1,100 +1,23 @@
- allocate/free tags.
-Not tested.
-
-OK - test blockMesh with cyclics
-unitTestCases/singleCyclic/
-
-OK - test cyclics sequential running.
-unitTestCases/singleCyclic/
-
-OK - test decomposePar
-tested channel395
-
-OK - FaceCellWave
-    unitTestCases/twoCavityCyclicForWallDistance/
-
-OK - non-parallel finite volume : channelFoam
-    unitTestCases/channel395-splitCyclic vs. channel395-dev
-
-OK - parallel finite volume with processorCyclic: channelFoam
-    unitTestCases/channel395-splitCyclic vs. channel395-dev
-
-OK - preProcessing/foamUpgradeCyclics
-
-OK - gamg - sequential.
-Tested on channel395-splitCyclic with GAMG.
-OK - gamg parallel.
-Tested on channel395-splitCyclic with GAMG.
-
- initTransfer in GAMGprocessorInterfaces using nonblocking+tags
-untested.
-
-OK - cyclic baffles.
-Tested on t-junction-with-fan
-
-OK. - jumpCyclics/fanFvPatchField. All usages of jump() now need to account
-for being owner() or not.
-Tested on t-junction-with-fan.
-
-OK - regionSplit
-tested on singleCyclic
-
-OK - pointFields on cyclics. volPointInterpolation.
-tested on channel395-splitCyclic
-
-OK - fvMeshSubset
-tested on singleCyclic
-
-OK - pointEdgeWave (maybe test through inversePointDistanceDiffusivity?)
-tested on twoCavityCyclicForWallDistance
-
-OK - scotchDecomp
-tested with testCalcCSR on twoCavityCyclicForWallDistance
-
-NOT WORKING - fvMeshDistribute to split cyclic patches into ones
-  with different separation.
-tested on singleCyclic
-
-OK - test createPatch pointSync
-note: only works if face-centre position of 0th faces is ok since uses
-this for separation. Should in fact make cyclic planar using patch centre and
-normal?
-test on twoCavityCyclicForWallDistance with point (0 1 0) set to (0 1.001 0)
-
-NO PROBLEM - renumberMesh
-It doesn't do renumbering through cyclics.
-
-OK - rotational cyclics.
-Tested on movingCone-with-cyclics
-
-OK - LUscalarMatrix::convert still expects interfaces to be cyclic
-tested on channel395 with 'directSolveCoarsest true;' 
-
-OK - grep for size()/2
-
- all tutorials with cyclics:
-    OK - incompressible/DNS/dnsFoam/boxTurb16
-    OK - incompressible/channelFoam/channel395
-    slight differences due to divergence. combustion/XiFoam/les/pitzDaily3D
-    OK - no cyclics. combustion/fireFoam/les/smallPoolFire2D
-    discreteMethods/dsmcFoam/freeSpacePeriodic
-    discreteMethods/dsmcFoam/wedge15Ma5
-    discreteMethods/molecularDynamics/mdEquilibrationFoam/periodicCubeArgon
-    OK - incompressible/boundaryFoam/boundaryLaunderSharma
-    OK - incompressible/boundaryFoam/boundaryWallFunctions
-    OK - incompressible/boundaryFoam/boundaryWallFunctionsProfile
-    OK - needs createBaffles. incompressible/pimpleFoam/t-junction-with-fan
-    OK - incompressible/simpleSRFFoam/mixer
-    OK - needs createBaffles. lagrangian/porousExplicitSourceReactingParcelFoam/filter
-    needs special coupledbcs. lagrangian/reactingParcelFilmFoam/multipleBoxes
+- check 
+    new fvMesh
+    new fvMeshSubset
+for consistency with createMesh.H
+
+
+
+- Check the following:
+
+doc/changes/inotify.txt
+ 
+
+
+
+
+
+
+
+
+


-OK - createBaffles

- have foamUpgradeCyclics split 'value' field
- activeBaffleVelocity
- kivaToFoam/readKivaGrid.H sorts cyclics (but in incorrect order?)
- isoSurface.C
- referredCellList.C
- work out scheduled communication?
-OK - add neighbourPatch checking to 16x.
--- a/applications/solvers/DNS/dnsFoam/readTransportProperties.H
+++ b/applications/solvers/DNS/dnsFoam/readTransportProperties.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/DNS/dnsFoam/readTurbulenceProperties.H
+++ b/applications/solvers/DNS/dnsFoam/readTurbulenceProperties.H
@ -7,7 +7,7 @@
            "turbulenceProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/basic/laplacianFoam/createFields.H
+++ b/applications/solvers/basic/laplacianFoam/createFields.H
@ -23,7 +23,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/basic/scalarTransportFoam/createFields.H
+++ b/applications/solvers/basic/scalarTransportFoam/createFields.H
@ -39,7 +39,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/combustion/PDRFoam/XiModels/XiEqModels/SCOPEXiEq/SCOPEXiEq.C
+++ b/applications/solvers/combustion/PDRFoam/XiModels/XiEqModels/SCOPEXiEq/SCOPEXiEq.C
@ -62,7 +62,7 @@ Foam::XiEqModels::SCOPEXiEq::SCOPEXiEq
                "combustionProperties",
                Su.mesh().time().constant(),
                Su.mesh(),
-                IOobject::MUST_READ
+                IOobject::MUST_READ_IF_MODIFIED
            )
        ),
        thermo
--- a/applications/solvers/combustion/PDRFoam/createFields.H
+++ b/applications/solvers/combustion/PDRFoam/createFields.H
@ -110,7 +110,7 @@
            "PDRProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/combustion/PDRFoam/readCombustionProperties.H
+++ b/applications/solvers/combustion/PDRFoam/readCombustionProperties.H
@ -7,7 +7,7 @@
            "combustionProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/combustion/XiFoam/readCombustionProperties.H
+++ b/applications/solvers/combustion/XiFoam/readCombustionProperties.H
@ -7,7 +7,7 @@
            "combustionProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/combustion/dieselEngineFoam/readCombustionProperties.H
+++ b/applications/solvers/combustion/dieselEngineFoam/readCombustionProperties.H
@ -7,7 +7,7 @@ IOdictionary combustionProperties
        "combustionProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/solvers/combustion/fireFoam/createFields.H
+++ b/applications/solvers/combustion/fireFoam/createFields.H
@ -65,7 +65,7 @@ IOdictionary combustionProperties
        "combustionProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/solvers/combustion/reactingFoam/readChemistryProperties.H
+++ b/applications/solvers/combustion/reactingFoam/readChemistryProperties.H
@ -7,7 +7,7 @@ IOdictionary chemistryProperties
        "chemistryProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE,
        false
    )
--- a/applications/solvers/combustion/rhoReactingFoam/readChemistryProperties.H
+++ b/applications/solvers/combustion/rhoReactingFoam/readChemistryProperties.H
@ -7,7 +7,7 @@ IOdictionary chemistryProperties
        "chemistryProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE,
        false
    )
--- a/applications/solvers/compressible/rhoCentralFoam/readThermophysicalProperties.H
+++ b/applications/solvers/compressible/rhoCentralFoam/readThermophysicalProperties.H
@ -9,7 +9,7 @@ IOdictionary thermophysicalProperties
        "thermophysicalProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/solvers/compressible/rhoSonicFoam/readThermodynamicProperties.H
+++ b/applications/solvers/compressible/rhoSonicFoam/readThermodynamicProperties.H
@ -7,7 +7,7 @@
            "thermodynamicProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/compressible/rhopSonicFoam/readThermodynamicProperties.H
+++ b/applications/solvers/compressible/rhopSonicFoam/readThermodynamicProperties.H
@ -7,7 +7,7 @@
            "thermodynamicProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/compressible/sonicDyMFoam/readThermodynamicProperties.H
+++ b/applications/solvers/compressible/sonicDyMFoam/readThermodynamicProperties.H
@ -7,7 +7,7 @@
            "thermodynamicProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/compressible/sonicDyMFoam/readTransportProperties.H
+++ b/applications/solvers/compressible/sonicDyMFoam/readTransportProperties.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/compressible/sonicLiquidFoam/readThermodynamicProperties.H
+++ b/applications/solvers/compressible/sonicLiquidFoam/readThermodynamicProperties.H
@ -7,7 +7,7 @@
            "thermodynamicProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/compressible/sonicLiquidFoam/readTransportProperties.H
+++ b/applications/solvers/compressible/sonicLiquidFoam/readTransportProperties.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/discreteMethods/molecularDynamics/mdEquilibrationFoam/readmdEquilibrationDict.H
+++ b/applications/solvers/discreteMethods/molecularDynamics/mdEquilibrationFoam/readmdEquilibrationDict.H
@ -7,7 +7,7 @@ IOdictionary mdEquilibrationDict
        "mdEquilibrationDict",
        runTime.system(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/solvers/electromagnetics/electrostaticFoam/createFields.H
+++ b/applications/solvers/electromagnetics/electrostaticFoam/createFields.H
@ -7,7 +7,7 @@
            "physicalProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/electromagnetics/magneticFoam/createFields.H
+++ b/applications/solvers/electromagnetics/magneticFoam/createFields.H
@ -21,7 +21,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/electromagnetics/mhdFoam/createFields.H
+++ b/applications/solvers/electromagnetics/mhdFoam/createFields.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/financial/financialFoam/createFields.H
+++ b/applications/solvers/financial/financialFoam/createFields.H
@ -7,7 +7,7 @@
            "financialProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/heatTransfer/chtMultiRegionFoam/regionProperties/regionProperties.C
+++ b/applications/solvers/heatTransfer/chtMultiRegionFoam/regionProperties/regionProperties.C
@ -36,7 +36,7 @@ Foam::regionProperties::regionProperties(const Time& runTime)
            "regionProperties",
            runTime.time().constant(),
            runTime.db(),
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    ),
--- a/applications/solvers/incompressible/boundaryFoam/createFields.H
+++ b/applications/solvers/incompressible/boundaryFoam/createFields.H
@ -44,7 +44,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/incompressible/channelFoam/readTransportProperties.H
+++ b/applications/solvers/incompressible/channelFoam/readTransportProperties.H
@ -6,7 +6,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/applications/solvers/incompressible/icoFoam/createFields.H
+++ b/applications/solvers/incompressible/icoFoam/createFields.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/incompressible/shallowWaterFoam/readGravitationalAcceleration.H
+++ b/applications/solvers/incompressible/shallowWaterFoam/readGravitationalAcceleration.H
@ -7,7 +7,7 @@ IOdictionary gravitationalProperties
        "gravitationalProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/solvers/lagrangian/coalChemistryFoam/readChemistryProperties.H
+++ b/applications/solvers/lagrangian/coalChemistryFoam/readChemistryProperties.H
@ -7,7 +7,7 @@ IOdictionary chemistryProperties
        "chemistryProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE,
        false
    )
--- a/applications/solvers/lagrangian/incompressibleUncoupledKinematicParcelFoam/createFields.H
+++ b/applications/solvers/lagrangian/incompressibleUncoupledKinematicParcelFoam/createFields.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/lagrangian/porousExplicitSourceReactingParcelFoam/readChemistryProperties.H
+++ b/applications/solvers/lagrangian/porousExplicitSourceReactingParcelFoam/readChemistryProperties.H
@ -7,7 +7,7 @@ IOdictionary chemistryProperties
        "chemistryProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE,
        false
    )
--- a/applications/solvers/lagrangian/reactingParcelFilmFoam/createFields.H
+++ b/applications/solvers/lagrangian/reactingParcelFilmFoam/createFields.H
@ -97,7 +97,7 @@
            "additionalControls",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/lagrangian/reactingParcelFilmFoam/readChemistryProperties.H
+++ b/applications/solvers/lagrangian/reactingParcelFilmFoam/readChemistryProperties.H
@ -7,7 +7,7 @@ IOdictionary chemistryProperties
        "chemistryProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE,
        false
    )
--- a/applications/solvers/lagrangian/reactingParcelFoam/readChemistryProperties.H
+++ b/applications/solvers/lagrangian/reactingParcelFoam/readChemistryProperties.H
@ -7,7 +7,7 @@ IOdictionary chemistryProperties
        "chemistryProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE,
        false
    )
--- a/applications/solvers/multiphase/bubbleFoam/createFields.H
+++ b/applications/solvers/multiphase/bubbleFoam/createFields.H
@ -91,7 +91,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/multiphase/bubbleFoam/createRASTurbulence.H
+++ b/applications/solvers/multiphase/bubbleFoam/createRASTurbulence.H
@ -5,7 +5,7 @@
            "RASProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/multiphase/cavitatingFoam/readThermodynamicProperties.H
+++ b/applications/solvers/multiphase/cavitatingFoam/readThermodynamicProperties.H
@ -7,7 +7,7 @@
            "thermodynamicProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/multiphase/interPhaseChangeFoam/phaseChangeTwoPhaseMixtures/phaseChangeTwoPhaseMixture/phaseChangeTwoPhaseMixtureNew.C
+++ b/applications/solvers/multiphase/interPhaseChangeFoam/phaseChangeTwoPhaseMixtures/phaseChangeTwoPhaseMixture/phaseChangeTwoPhaseMixtureNew.C
@ -46,7 +46,7 @@ Foam::phaseChangeTwoPhaseMixture::New
                "transportProperties",
                U.time().constant(),
                U.db(),
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE,
                false
            )
--- a/applications/solvers/multiphase/settlingFoam/createFields.H
+++ b/applications/solvers/multiphase/settlingFoam/createFields.H
@ -50,7 +50,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
@ -184,7 +184,7 @@
            "RASProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/multiphase/twoPhaseEulerFoam/createFields.H
+++ b/applications/solvers/multiphase/twoPhaseEulerFoam/createFields.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
@ -153,7 +153,7 @@
            "interfacialProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/multiphase/twoPhaseEulerFoam/kineticTheoryModels/kineticTheoryModel/kineticTheoryModel.C
+++ b/applications/solvers/multiphase/twoPhaseEulerFoam/kineticTheoryModels/kineticTheoryModel/kineticTheoryModel.C
@ -56,7 +56,7 @@ Foam::kineticTheoryModel::kineticTheoryModel
            "kineticTheoryProperties",
            Ua_.time().constant(),
            Ua_.mesh(),
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    ),
--- a/applications/solvers/multiphase/twoPhaseEulerFoam/readPPProperties.H
+++ b/applications/solvers/multiphase/twoPhaseEulerFoam/readPPProperties.H
@ -5,7 +5,7 @@
            "ppProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/stressAnalysis/solidDisplacementFoam/readMechanicalProperties.H
+++ b/applications/solvers/stressAnalysis/solidDisplacementFoam/readMechanicalProperties.H
@ -7,7 +7,7 @@
            "mechanicalProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/solvers/stressAnalysis/solidDisplacementFoam/readThermalProperties.H
+++ b/applications/solvers/stressAnalysis/solidDisplacementFoam/readThermalProperties.H
@ -7,7 +7,7 @@
            "thermalProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/test/LduMatrix/createFields.H
+++ b/applications/test/LduMatrix/createFields.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/test/dataEntry/testDataEntry.C
+++ b/applications/test/dataEntry/testDataEntry.C
@ -48,7 +48,7 @@ int main(int argc, char *argv[])
            "dataEntryProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/test/fvSolutionCombine/fvSolutionCombine.C
+++ b/applications/test/fvSolutionCombine/fvSolutionCombine.C
@ -116,7 +116,7 @@ int main(int argc, char *argv[])
            dictName,
            "system",
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/applications/utilities/errorEstimation/estimateScalarError/estimateScalarError.C
+++ b/applications/utilities/errorEstimation/estimateScalarError/estimateScalarError.C
@ -57,7 +57,7 @@ int main(int argc, char *argv[])
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/errorEstimation/icoErrorEstimate/icoErrorEstimate.C
+++ b/applications/utilities/errorEstimation/icoErrorEstimate/icoErrorEstimate.C
@ -56,7 +56,7 @@ int main(int argc, char *argv[])
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/errorEstimation/icoMomentError/icoMomentError.C
+++ b/applications/utilities/errorEstimation/icoMomentError/icoMomentError.C
@ -57,7 +57,7 @@ int main(int argc, char *argv[])
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/errorEstimation/momentScalarError/momentScalarError.C
+++ b/applications/utilities/errorEstimation/momentScalarError/momentScalarError.C
@ -58,7 +58,7 @@ int main(int argc, char *argv[])
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/mesh/advanced/autoRefineMesh/autoRefineMesh.C
+++ b/applications/utilities/mesh/advanced/autoRefineMesh/autoRefineMesh.C
@ -639,7 +639,7 @@ int main(int argc, char *argv[])
        "motionProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    );

@ -669,7 +669,7 @@ int main(int argc, char *argv[])
            "autoRefineMeshDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/mesh/advanced/combinePatchFaces/combinePatchFaces.C
+++ b/applications/utilities/mesh/advanced/combinePatchFaces/combinePatchFaces.C
@ -74,7 +74,7 @@ void checkSnapMesh
            "snapMeshDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/mesh/advanced/modifyMesh/modifyMesh.C
+++ b/applications/utilities/mesh/advanced/modifyMesh/modifyMesh.C
@ -346,7 +346,7 @@ int main(int argc, char *argv[])
            "modifyMeshDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/mesh/advanced/selectCells/edgeStats.C
+++ b/applications/utilities/mesh/advanced/selectCells/edgeStats.C
@ -78,7 +78,7 @@ Foam::edgeStats::edgeStats(const polyMesh& mesh)
        "motionProperties",
        mesh.time().constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    );

--- a/applications/utilities/mesh/advanced/selectCells/selectCells.C
+++ b/applications/utilities/mesh/advanced/selectCells/selectCells.C
@ -346,7 +346,7 @@ int main(int argc, char *argv[])
            "selectCellsDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/mesh/conversion/foamToStarMesh/getTimeIndex.H
+++ b/applications/utilities/mesh/conversion/foamToStarMesh/getTimeIndex.H
@ -29,7 +29,7 @@
                    runTime.timeName(),
                    "uniform",
                    runTime,
-                    IOobject::MUST_READ,
+                    IOobject::MUST_READ_IF_MODIFIED,
                    IOobject::NO_WRITE,
                    false
                )
--- a/applications/utilities/mesh/conversion/foamToSurface/getTimeIndex.H
+++ b/applications/utilities/mesh/conversion/foamToSurface/getTimeIndex.H
@ -29,7 +29,7 @@
                    runTime.timeName(),
                    "uniform",
                    runTime,
-                    IOobject::MUST_READ,
+                    IOobject::MUST_READ_IF_MODIFIED,
                    IOobject::NO_WRITE,
                    false
                )
--- a/applications/utilities/mesh/generation/blockMesh/blockMeshApp.C
+++ b/applications/utilities/mesh/generation/blockMesh/blockMeshApp.C
@ -121,7 +121,7 @@ int main(int argc, char *argv[])
                  : dictPath
                ),
                runTime,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE,
                false
            )
@ -137,7 +137,7 @@ int main(int argc, char *argv[])
                runTime.constant(),
                polyMeshDir,
                runTime,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE,
                false
            )
--- a/applications/utilities/mesh/generation/extrudeMesh/extrudeMesh.C
+++ b/applications/utilities/mesh/generation/extrudeMesh/extrudeMesh.C
@ -218,7 +218,7 @@ int main(int argc, char *argv[])
            runTimeExtruded.constant(),
            regionDir,
            runTimeExtruded,
-            IOobject::MUST_READ
+            IOobject::MUST_READ_IF_MODIFIED
        )
    );

--- a/applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C
+++ b/applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C
@ -144,7 +144,7 @@ int main(int argc, char *argv[])
            "decomposeParDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
@ -157,7 +157,7 @@ int main(int argc, char *argv[])
            "snappyHexMeshDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
       )
    );
--- a/applications/utilities/mesh/manipulation/createPatch/createPatch.C
+++ b/applications/utilities/mesh/manipulation/createPatch/createPatch.C
@ -532,7 +532,7 @@ int main(int argc, char *argv[])
              : word::null
            ),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/applications/utilities/mesh/manipulation/mirrorMesh/mirrorFvMesh.C
+++ b/applications/utilities/mesh/manipulation/mirrorMesh/mirrorFvMesh.C
@ -39,7 +39,7 @@ Foam::mirrorFvMesh::mirrorFvMesh(const IOobject& io)
            "mirrorMeshDict",
            time().system(),
            *this,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    ),
--- a/applications/utilities/mesh/manipulation/mirrorMesh/readMirrorDict.H
+++ b/applications/utilities/mesh/manipulation/mirrorMesh/readMirrorDict.H
@ -7,7 +7,7 @@
            "mirrorMeshDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/mesh/manipulation/refineMesh/refineMesh.C
+++ b/applications/utilities/mesh/manipulation/refineMesh/refineMesh.C
@ -334,7 +334,7 @@ int main(int argc, char *argv[])
                "refineMeshDict",
                runTime.system(),
                mesh,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
--- a/applications/utilities/mesh/manipulation/renumberMesh/renumberMesh.C
+++ b/applications/utilities/mesh/manipulation/renumberMesh/renumberMesh.C
@ -483,7 +483,7 @@ int main(int argc, char *argv[])
                "decomposeParDict",
                runTime.system(),
                mesh,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
--- a/applications/utilities/mesh/manipulation/stitchMesh/stitchMesh.C
+++ b/applications/utilities/mesh/manipulation/stitchMesh/stitchMesh.C
@ -298,7 +298,7 @@ int main(int argc, char *argv[])
                args.options()["toleranceDict"],
                runTime.constant(),
                mesh,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
--- a/applications/utilities/mesh/manipulation/topoSet/topoSet.C
+++ b/applications/utilities/mesh/manipulation/topoSet/topoSet.C
@ -83,7 +83,7 @@ int main(int argc, char *argv[])
            (
                dictPath,
                mesh,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
          : IOobject
@ -91,7 +91,7 @@ int main(int argc, char *argv[])
                dictName,
                runTime.system(),
                mesh,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        ) 
--- a/applications/utilities/parallelProcessing/decomposePar/decomposePar.C
+++ b/applications/utilities/parallelProcessing/decomposePar/decomposePar.C
@ -163,7 +163,7 @@ int main(int argc, char *argv[])
                runTime.time().system(),
                regionDir,          // use region if non-standard
                runTime,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE,
                false
            )
--- a/applications/utilities/parallelProcessing/decomposePar/domainDecomposition.C
+++ b/applications/utilities/parallelProcessing/decomposePar/domainDecomposition.C
@ -94,7 +94,7 @@ Foam::domainDecomposition::domainDecomposition(const IOobject& io)
            "decomposeParDict",
            time().system(),
            *this,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    ),
--- a/applications/utilities/parallelProcessing/redistributeMeshPar/redistributeMeshPar.C
+++ b/applications/utilities/parallelProcessing/redistributeMeshPar/redistributeMeshPar.C
@ -581,7 +581,7 @@ int main(int argc, char *argv[])
            "decomposeParDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/postProcessing/dataConversion/foamDataToFluent/foamDataToFluent.C
+++ b/applications/utilities/postProcessing/dataConversion/foamDataToFluent/foamDataToFluent.C
@ -94,7 +94,7 @@ int main(int argc, char *argv[])
                "foamDataToFluentDict",
                runTime.system(),
                mesh,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
--- a/applications/utilities/postProcessing/dataConversion/foamToEnsightParts/getTimeIndex.H
+++ b/applications/utilities/postProcessing/dataConversion/foamToEnsightParts/getTimeIndex.H
@ -26,7 +26,7 @@

        if (io.headerOk())
        {
-            io.readOpt() = IOobject::MUST_READ;
+            io.readOpt() = IOobject::MUST_READ_IF_MODIFIED;
            IOdictionary timeObject(io);

            timeObject.lookup("index") >> timeIndex;
--- a/applications/utilities/postProcessing/dataConversion/foamToGMV/readConversionProperties.H
+++ b/applications/utilities/postProcessing/dataConversion/foamToGMV/readConversionProperties.H
@ -5,7 +5,7 @@ IOdictionary conversionProperties
        "conversionProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/utilities/postProcessing/graphics/PV3Readers/PV3FoamReader/vtkPV3Foam/vtkPV3Foam.C
+++ b/applications/utilities/postProcessing/graphics/PV3Readers/PV3FoamReader/vtkPV3Foam/vtkPV3Foam.C
@ -444,7 +444,7 @@ void Foam::vtkPV3Foam::updateFoamMesh()
                meshRegion_,
                dbPtr_().timeName(),
                dbPtr_(),
-                IOobject::MUST_READ
+                IOobject::MUST_READ_IF_MODIFIED
            )
        );

--- a/applications/utilities/postProcessing/graphics/PV3Readers/PV3blockMeshReader/vtkPV3blockMesh/vtkPV3blockMesh.C
+++ b/applications/utilities/postProcessing/graphics/PV3Readers/PV3blockMeshReader/vtkPV3blockMesh/vtkPV3blockMesh.C
@ -315,7 +315,7 @@ void Foam::vtkPV3blockMesh::updateFoamMesh()
                dbPtr_().constant(),
                polyMesh::meshSubDir,
                dbPtr_(),
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE,
                false
            )
--- a/applications/utilities/postProcessing/graphics/fieldview9Reader/readerDatabase.C
+++ b/applications/utilities/postProcessing/graphics/fieldview9Reader/readerDatabase.C
@ -260,7 +260,7 @@ void Foam::readerDatabase::loadMesh()
    meshPtr_ = new fvMeshSubset
    (
        *runTimePtr_,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::AUTO_WRITE
    );

--- a/applications/utilities/postProcessing/lagrangian/particleTracks/createFields.H
+++ b/applications/utilities/postProcessing/lagrangian/particleTracks/createFields.H
@ -5,7 +5,7 @@ IOdictionary propsDict
        "particleTrackProperties",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ
+        IOobject::MUST_READ_IF_MODIFIED
    )
 );

--- a/applications/utilities/postProcessing/miscellaneous/execFlowFunctionObjects/execFlowFunctionObjects.C
+++ b/applications/utilities/postProcessing/miscellaneous/execFlowFunctionObjects/execFlowFunctionObjects.C
@ -62,7 +62,7 @@ namespace Foam
                    args["dict"],
                    runTime.system(),
                    runTime,
-                    IOobject::MUST_READ
+                    IOobject::MUST_READ_IF_MODIFIED
                )
            );

@ -130,7 +130,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
            "RASProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        );
@ -140,7 +140,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
            "LESProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        );
@ -184,7 +184,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
                    "transportProperties",
                    runTime.constant(),
                    mesh,
-                    IOobject::MUST_READ,
+                    IOobject::MUST_READ_IF_MODIFIED,
                    IOobject::NO_WRITE
                )
            );
@ -214,7 +214,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
            "RASProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        );
@ -224,7 +224,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
            "LESProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        );
@ -266,7 +266,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
                    "transportProperties",
                    runTime.constant(),
                    mesh,
-                    IOobject::MUST_READ,
+                    IOobject::MUST_READ_IF_MODIFIED,
                    IOobject::NO_WRITE
                )
            );
--- a/applications/utilities/postProcessing/miscellaneous/pdfPlot/createFields.H
+++ b/applications/utilities/postProcessing/miscellaneous/pdfPlot/createFields.H
@ -5,7 +5,7 @@
            "pdfDict",
            runTime.constant(),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/postProcessing/miscellaneous/postChannel/postChannel.C
+++ b/applications/utilities/postProcessing/miscellaneous/postChannel/postChannel.C
@ -69,7 +69,7 @@ int main(int argc, char *argv[])
            "postChannelDict",
            mesh.time().constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/postProcessing/miscellaneous/postChannel/readTransportProperties.H
+++ b/applications/utilities/postProcessing/miscellaneous/postChannel/readTransportProperties.H
@ -7,7 +7,7 @@
            "transportProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/postProcessing/velocityField/Mach/Mach.C
+++ b/applications/utilities/postProcessing/velocityField/Mach/Mach.C
@ -98,7 +98,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
                    "thermodynamicProperties",
                    runTime.constant(),
                    mesh,
-                    IOobject::MUST_READ,
+                    IOobject::MUST_READ_IF_MODIFIED,
                    IOobject::NO_WRITE
                )
            );
--- a/applications/utilities/postProcessing/velocityField/Mach/readThermodynamicProperties.H
+++ b/applications/utilities/postProcessing/velocityField/Mach/readThermodynamicProperties.H
@ -7,7 +7,7 @@
            "thermodynamicProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/postProcessing/velocityField/Pe/Pe.C
+++ b/applications/utilities/postProcessing/velocityField/Pe/Pe.C
@ -81,7 +81,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
            "RASProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        );

@ -90,7 +90,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
            "LESProperties",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        );

@ -174,7 +174,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
                        "transportProperties",
                        runTime.constant(),
                        mesh,
-                        IOobject::MUST_READ,
+                        IOobject::MUST_READ_IF_MODIFIED,
                        IOobject::NO_WRITE
                    )
                );
@ -299,7 +299,7 @@ void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh)
                        "transportProperties",
                        runTime.constant(),
                        mesh,
-                        IOobject::MUST_READ,
+                        IOobject::MUST_READ_IF_MODIFIED,
                        IOobject::NO_WRITE
                    )
                );
--- a/applications/utilities/preProcessing/boxTurb/readBoxTurbDict.H
+++ b/applications/utilities/preProcessing/boxTurb/readBoxTurbDict.H
@ -7,7 +7,7 @@
            "boxTurbDict",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/preProcessing/changeDictionary/changeDictionary.C
+++ b/applications/utilities/preProcessing/changeDictionary/changeDictionary.C
@ -292,7 +292,7 @@ int main(int argc, char *argv[])
            "changeDictionaryDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
@ -405,7 +405,7 @@ int main(int argc, char *argv[])
                    fieldName,
                    instance,
                    mesh,
-                    IOobject::MUST_READ,
+                    IOobject::MUST_READ_IF_MODIFIED,
                    IOobject::NO_WRITE,
                    false
                )
--- a/applications/utilities/preProcessing/dsmcInitialise/dsmcInitialise.C
+++ b/applications/utilities/preProcessing/dsmcInitialise/dsmcInitialise.C
@ -50,7 +50,7 @@ int main(int argc, char *argv[])
            "dsmcInitialiseDict",
            mesh.time().system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/preProcessing/engineSwirl/createFields.H
+++ b/applications/utilities/preProcessing/engineSwirl/createFields.H
@ -7,7 +7,7 @@ IOdictionary engineGeometry
        "engineGeometry",
        runTime.constant(),
        mesh,
-        IOobject::MUST_READ,
+        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
 );
--- a/applications/utilities/preProcessing/foamUpgradeCyclics/foamUpgradeCyclics.C
+++ b/applications/utilities/preProcessing/foamUpgradeCyclics/foamUpgradeCyclics.C
@ -279,7 +279,7 @@ void rewriteField
            fieldName,
            runTime.timeName(),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/applications/utilities/preProcessing/foamUpgradeFvSolution/foamUpgradeFvSolution.C
+++ b/applications/utilities/preProcessing/foamUpgradeFvSolution/foamUpgradeFvSolution.C
@ -70,7 +70,7 @@ int main(int argc, char *argv[])
            "fvSolution",
            runTime.system(),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/applications/utilities/preProcessing/mapFields/mapFields.C
+++ b/applications/utilities/preProcessing/mapFields/mapFields.C
@ -291,7 +291,7 @@ int main(int argc, char *argv[])
                "mapFieldsDict",
                runTimeTarget.system(),
                runTimeTarget,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE,
                false
            )
@ -310,7 +310,7 @@ int main(int argc, char *argv[])
                "decomposeParDict",
                runTimeSource.system(),
                runTimeSource,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
@ -375,7 +375,7 @@ int main(int argc, char *argv[])
                "decomposeParDict",
                runTimeTarget.system(),
                runTimeTarget,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
@ -446,7 +446,7 @@ int main(int argc, char *argv[])
                "decomposeParDict",
                runTimeSource.system(),
                runTimeSource,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
@ -464,7 +464,7 @@ int main(int argc, char *argv[])
                "decomposeParDict",
                runTimeTarget.system(),
                runTimeTarget,
-                IOobject::MUST_READ,
+                IOobject::MUST_READ_IF_MODIFIED,
                IOobject::NO_WRITE
            )
        );
--- a/applications/utilities/preProcessing/mdInitialise/mdInitialise.C
+++ b/applications/utilities/preProcessing/mdInitialise/mdInitialise.C
@ -44,7 +44,7 @@ int main(int argc, char *argv[])
            "mdInitialiseDict",
            runTime.system(),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/applications/utilities/preProcessing/setFields/setFields.C
+++ b/applications/utilities/preProcessing/setFields/setFields.C
@ -186,7 +186,7 @@ int main(int argc, char *argv[])
            "setFieldsDict",
            runTime.system(),
            mesh,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/preProcessing/wallFunctionTable/wallFunctionTableApp.C
+++ b/applications/utilities/preProcessing/wallFunctionTable/wallFunctionTableApp.C
@ -47,7 +47,7 @@ int main(int argc, char *argv[])
            "wallFunctionDict",
            runTime.constant(),
            mesh,
-            IOobject::MUST_READ
+            IOobject::MUST_READ_IF_MODIFIED
        )
    );

--- a/applications/utilities/surface/surfaceMeshExport/surfaceMeshExport.C
+++ b/applications/utilities/surface/surfaceMeshExport/surfaceMeshExport.C
@ -241,7 +241,7 @@ int main(int argc, char *argv[])
            importName,
            runTime.constant(),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
--- a/applications/utilities/thermophysical/equilibriumCO/equilibriumCO.C
+++ b/applications/utilities/thermophysical/equilibriumCO/equilibriumCO.C
@ -62,7 +62,7 @@ int main(int argc, char *argv[])
            "BurcatCpData",
            runTime.constant(),
            runTime,
-            IOobject::MUST_READ,
+            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE,
            false
        )
--- a/src/OSspecific/POSIX/fileMonitor.C
+++ b/src/OSspecific/POSIX/fileMonitor.C
@ -30,6 +30,7 @@ Class
 #include "IOstreams.H"
 #include "Pstream.H"
 #include "PackedList.H"
+#include "PstreamReduceOps.H"

 #ifdef FOAM_USE_STAT
 #   include "OSspecific.H"
@ -57,12 +58,14 @@ const Foam::NamedEnum<Foam::fileMonitor::fileState, 3>

 namespace Foam
 {
-    class fileStateEqOp
+    // Reduction operator for PackedList of fileState
+    class reduceFileStates
    {
        public:
-        void operator()(unsigned int& x, const unsigned int& y) const
+        unsigned int operator()(const unsigned int x, const unsigned int y)
+        const
        {
-            // x,y are list of 2bits representing fileState
+            // x,y are sets of 2bits representing fileState

            unsigned int mask = 3u;
            unsigned int shift = 0;
@ -82,7 +85,17 @@ namespace Foam
                shift += 2;
                mask <<= 2;
            }
-            x = result;
+            return result;
+        }
+    };
+
+    // Combine operator for PackedList of fileState
+    class combineReduceFileStates
+    {
+        public:
+        void operator()(unsigned int& x, const unsigned int y) const
+        {
+            x = reduceFileStates()(x, y);
        }
    };
 }
@ -323,7 +336,19 @@ void Foam::fileMonitor::updateStates(const bool syncPar) const
        // Save local state for warning message below
        PackedList<2> thisProcStats(stats);

-        Pstream::listCombineGather(stats.storage(), fileStateEqOp());
+        if (stats.storage().size() == 1)
+        {
+            // Optimisation valid for most cases.
+            reduce(stats.storage()[0], reduceFileStates());
+        }
+        else
+        {
+            Pstream::listCombineGather
+            (
+                stats.storage(),
+                combineReduceFileStates()
+            );
+        }

        i = 0;
        forAllIter(Map<fileState>, state_, iter)
--- a/Show More
+++ b/Show More