Porting from 1.x to 2.x

This guide helps you to upgrade from preCICE 1.x to preCICE 2.x.

Tip: Reviving that old adapter? Good opportunity to learn about some best practices and make it easier to reuse and maintain! There are guidelines for adapters and guidelines for application cases .

Tip: Also have a look at the API documentation and minimal reference implementations .

preCICE API

Single-step setup

This is described in detail in #614 and was done to simplify the setup. Change:

-  SolverInterface interface(solverName, commRank, commSize);
-  interface.configure(configFileName);
+  SolverInterface interface(solverName, configFileName, commRank, commSize);

Typical error message that should lead you here:

error: no matching function for call to ‘precice::SolverInterface::SolverInterface(std::__cxx11::string&, int, Foam::label)’
         precice_ = new precice::SolverInterface(participantName_, Pstream::myProcNo(), Pstream::nProcs());

and

note: candidate: precice::SolverInterface::SolverInterface(const string&, const string&, int, int)
   SolverInterface(
   ^
.../SolverInterface.hpp:52:3: note:   candidate expects 4 arguments, 3 provided

Sorted out duplicate meaning of time step

Renamed API function isTimestepComplete to isTimeWindowComplete (#619 )

Clarified `fulfilledAction`

fulfilledAction was renamed to markActionFulfilled (#631 )

Language bindings

C

Moved to extras/bindings/c.
Separated into include (header) and src (implementation).
Renamed precicec_isCouplingTimestepComplete to precicec_isTimeWindowComplete.

Fortran

Moved the intrinsic Fortran bindings to extras/bindings/fortran.
Renamed the “Fortran 2003 bindings” to “Fortran module” and Precice_solver_if_module to precice. Moved them to precice/fortran-module .

Python

python bindings migration guide

preCICE configuration file

Renamed mapping:petrbf to mapping:rbf (see #572 ).
Remove master:mpi-single tags. preCICE defaults to master:mpi-single for parallel participants (see #572 ).
Remove distribution-type="..." from m2n tags. It now defaults to point-to-point, use the attribute enforce-gather-scatter=1 if this is not desired (see #572 ).
Renamed coupling-scheme configuration option timestep-length to time-window-size
Renamed coupling-scheme configuration option max-timesteps to max-time-windows
Renamed post-processing to acceleration
Renamed acceleration configuration option timesteps-reused to time-windows-reused
Renamed acceleration configuration option reused-timesteps-at-restart to reused-time-windows-at-restart
Renamed export configuration option timestep-interval to every-n-time-windows
Renamed action configuration option on-timestep-complete-post to on-time-window-complete-post

Building

Renamed CMake variables (#609 )
- MPI to PRECICE_MPICommunication
- PETSC to PRECICE_PETScMapping
- PYTHON to PRECICE_PythonActions
CMake CMAKE_BUILD_TYPE is automatically set to Debug, if empty
CMake variables for enabling C and Fortran
Removed SCons completely. You can do everything and much more with CMake .

Side-changes

All the tutorials are adapted for preCICE v2. You can still find a version compatible with preCICE v1.6.1 here .

Most of the adapters (all apart from the “under initial development” ones) are only supporting the latest version of preCICE. Make sure also that you are using the correct branch: an adapter’s develop is supposed to work with preCICE develop, and similar for master.

At the same time as preCICE v2, we also changed the configuration format of the OpenFOAM adapter: Instead of a yaml file, it is now an OpenFOAM dictionary, making installation even easier. Please refer to the Configuration page for more details.