specfem::MPI

specfem::MPI is a static class that provides an interface to MPI functionality within SPECFEM++. It manages MPI initialization and finalization, and provides static access to the rank and size of the MPI communicator.

class MPI

Static MPI wrapper for SPECFEM++.

This class provides a static interface to MPI functionality, eliminating the need to pass MPI pointers throughout the codebase.

Key features:

  • Static rank and size members accessible globally

  • Context-managed lifecycle (only Context can initialize/finalize)

  • Safety checks to prevent use outside Context scope

  • Minimal API focused on essential MPI operations

Usage: 

// After Context is initialized
int my_rank = specfem::MPI::get_rank();
int world_size = specfem::MPI::get_size();
specfem::MPI::sync();

Note

This class cannot be instantiated. All members are static.

Note

Only specfem::program::Context can initialize/finalize this class.

Public Static Functions

static inline void sync()

Synchronize all MPI processes (MPI_Barrier)

Throws:

Exits – with error code 1 if called outside Context scope

static inline void sync_all()

Synchronize all MPI processes (alias for sync())

Throws:

Exits – with error code 1 if called outside Context scope

static inline int get_rank()

Get MPI rank.

Throws:

Exits – with error code 1 if called outside Context scope

Returns:

int Current MPI rank

static inline int get_size()

Get MPI world size.

Throws:

Exits – with error code 1 if called outside Context scope

Returns:

int Total number of MPI processes

static inline bool main_proc()

Check if current process is the main process (rank 0)

Throws:

Exits – with error code 1 if called outside Context scope

Returns:

bool True if rank == 0

static inline int reduce(int lvalue, specfem::reduce_type reduce_op)

MPI reduce operation.

Parameters:

  • lvalue – Local value to reduce

  • reduce_op – Reduction operation (specfem::sum, specfem::min, specfem::max)

Throws:

Exits – with error code 1 if called outside Context scope

Returns:

Reduced value (only valid on root process)

static inline float reduce(float lvalue, specfem::reduce_type reduce_op)

MPI reduce operation for float.

Parameters:

  • lvalue – Local value to reduce

  • reduce_op – Reduction operation

Throws:

Exits – with error code 1 if called outside Context scope

Returns:

Reduced value (only valid on root process)

static inline double reduce(double lvalue, specfem::reduce_type reduce_op)

MPI reduce operation for double.

Parameters:

  • lvalue – Local value to reduce

  • reduce_op – Reduction operation

Throws:

Exits – with error code 1 if called outside Context scope

Returns:

Reduced value (only valid on root process)