NAME¶

MPI_T_event_get_num - Query the number of MPI_T event types

MPI_T_event_get_num — Query the number of MPI_T event types

OUTPUT PARAMETERS¶

DESCRIPTION¶

MPI_T_event_get_num can be used to query the current number of MPI_T event types.

The number of available event types can be queried with a call to MPI_T_event_get_num. An MPI implementation is allowed to increase the number of event types during the execution of an MPI process. However, MPI implementations are not allowed to change the index of an event type or to delete an event type once it has been made visible to the user.

Note:

DISCOVERING AVAILABLE EVENTS¶

Open MPI registers a set of event types and sources, such as communicator and session lifecycle, error-handler invocations, and (where the OS supports it) memory releases. To list the registered sources and event types from the command line, use:

ompi_info --event

To enumerate them programmatically, query the count and then each event's metadata with MPI_T_event_get_info <#mpi-t-event-get-info>:

#include <mpi.h>
#include <stdio.h>
int main(void) {


    int provided, i, num = 0;


    MPI_T_init_thread(MPI_THREAD_SINGLE, &provided);


    MPI_T_event_get_num(&num);


    for (i = 0; i < num; ++i) {


        char name[256];


        int name_len = sizeof(name), num_elements = 0, verbosity, bind;


        MPI_T_event_get_info(i, name, &name_len, &verbosity, NULL, NULL,


                             &num_elements, NULL, NULL, NULL, NULL, &bind);


        printf("event %d: %s (%d elements)\n", i, name, num_elements);


    }


    MPI_T_finalize();


    return 0;
}

ERRORS¶

MPI_T_event_get_num will fail if:

See also:

Author¶

The Open MPI community

Copyright¶

2003-2026, The Open MPI Community