MPI_BSEND_INIT(3)

🎀 NAME 🎀

okay bestie, welcome to MPI_BSEND_INIT(3) from Open MPI — yes, the buffered-send-init one, and it is literally here to help. 💅

MPI_Bsend_init — Builds a handle for a buffered send.

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✨ SYNTAX ✨

no improv, bestie, copy the syntax exactly 🫶

💻 C Syntax

          #include <mpi.h>

          int MPI_Bsend_init(const void *buf, int count, MPI_Datatype datatype,
              int dest, int tag, MPI_Comm comm, MPI_Request *request)

🧡 Fortran Syntax

          USE MPI
          ! or the older form: INCLUDE 'mpif.h'

          MPI_BSEND_INIT(BUF, COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR)
              <type>  BUF(*)
              INTEGER COUNT, DATATYPE, DEST, TAG,
              INTEGER COMM, REQUEST, IERROR

🦋 Fortran 2008 Syntax

          USE mpi_f08

          MPI_Bsend_init(buf, count, datatype, dest, tag, comm, request, ierror)
              TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: buf
              INTEGER, INTENT(IN) :: count, dest, tag
              TYPE(MPI_Datatype), INTENT(IN) :: datatype
              TYPE(MPI_Comm), INTENT(IN) :: comm
              TYPE(MPI_Request), INTENT(OUT) :: request
              INTEGER, OPTIONAL, INTENT(OUT) :: ierror

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🌸 INPUT PARAMETERS 🌸

the little inputs that make the magic happen ✨

• buf — Initial address of send buffer (choice).
• count — Number of elements sent (integer).
• datatype — Type of each element (handle).
• dest — Rank of destination</dest> (integer).
• tag — Message tag (integer).
• comm — Communicator (handle).

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🎁 OUTPUT PARAMETERS 🎁

what comes back out, bestie 💖

• request — Communication request (handle).
• ierror — Fortran only: Error status (integer).

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💌 DESCRIPTION 💌

okay so what does it actually do? Creates a persistent communication request for a buffered mode send, and binds to it all the arguments of a send operation. that's the whole vibe, no cap. ✨

A communication (send or receive) that uses a persistent request is initiated by the function MPI_Start.

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🚨 ERRORS 🚨

error time, bestie — this part is long but do not skip it 😭

Almost all MPI routines return an error value; C routines as the return result of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI_COMM_SELF and will call the associated MPI error handler. When MPI_COMM_SELF is not initialized (i.e., before MPI_Init/MPI_Init_thread, after MPI_Finalize, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling MPI_Comm_set_errhandler on MPI_COMM_SELF when using the World model, or the mpi_initial_errhandler CLI argument to mpiexec or info key to MPI_Comm_spawn/MPI_Comm_spawn_multiple. If no other appropriate error handler has been set, then the MPI_ERRORS_RETURN error handler is called for MPI I/O functions and the MPI_ERRORS_ABORT error handler is called for all other MPI functions.

Open MPI includes three predefined error handlers that can be used:

• MPI_ERRORS_ARE_FATAL — Causes the program to abort all connected MPI processes.
• MPI_ERRORS_ABORT — An error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if MPI_Abort was called on that communicator. If called on a window or file, acts as if MPI_Abort was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process.
• MPI_ERRORS_RETURN — Returns an error code to the application.

MPI applications can also implement their own error handlers by calling:

• MPI_Comm_create_errhandler then MPI_Comm_set_errhandler
• MPI_File_create_errhandler then MPI_File_set_errhandler
• MPI_Session_create_errhandler then MPI_Session_set_errhandler or at MPI_Session_init
• MPI_Win_create_errhandler then MPI_Win_set_errhandler

Note that MPI does not guarantee that an MPI program can continue past an error. fr fr, this is serious.

See the MPI man page for a full list of MPI error codes.

See the Error Handling section of the MPI-3.1 standard for more information.

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👀 SEE ALSO 👀

the required references, periodt 💅

• MPI_Send_init
• MPI_Start

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📜 COPYRIGHT 📜

2003-2026, The Open MPI Community

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xoxo from Open MPI 💖 — source/version Open MPI, page dated Sep 11, 2026. that's the whole manual page, bestie, mwah 💋