SHMEM_INT_PUT_NBI(3)

💅 SHMEM_INT_PUT_NBI — Open MPI, bestie ✨

okay so real talk: this is the Open MPI manual, and today we're talking about the nonblocking put squad 🫶

Here's the whole fam — every single one of these has its own page, and they're all serving the same vibe:

• shmem_putmem_nbi(3)
• shmem_char_put_nbi(3)
• shmem_short_put_nbi(3)
• shmem_int_put_nbi(3)
• shmem_long_put_nbi(3)
• shmem_longlong_put_nbi(3)
• shmem_float_put_nbi(3)
• shmem_double_put_nbi(3)
• shmem_longdouble_put_nbi(3)
• shmem_put8_nbi(3)
• shmem_put16_nbi(3)
• shmem_put32_nbi(3)
• shmem_put64_nbi(3)
• shmem_put128_nbi(3)

Those are the nonblocking put routines, and what they do is literally this: they give you a way to copy data from a contiguous local data object over to a data object on a specified PE. that's it, that's the whole job 💖

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✨ SYNOPSIS ✨

C or C++:

#include <mpp/shmem.h>

void shmem_putmem_nbi(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_char_put(char *dest, const char *source,
  size_t nelems, int pe)

void shmem_short_put(short *dest, const short *source,
  size_t nelems, int pe)

void shmem_int_put(int *dest, const int *source,
  size_t nelems, int pe)

void shmem_long_put(long *dest, const long *source,
  size_t nelems, int pe)

void shmem_longlong_put(long long *dest, const long long *source,
  size_t nelems, int pe)

void shmem_float_put(float *dest, const float *source,
  size_t nelems, int pe)

void shmem_double_put(double *dest, const double *source,
  size_t nelems, int pe)

void shmem_longdouble_put(long double *dest, const long double *source,
  size_t nelems, int pe)

void shmem_put8(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_put16(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_put32(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_put64(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_put128(void *dest, const void *source,
  size_t nelems, int pe)

(nope, I am not editing a single character of those, that's verbatim, periodt 💅)

Fortran:

INCLUDE "mpp/shmem.fh"

INTEGER nelems, pe

CALL SHMEM_PUTMEM_NBI(dest, source, nelems, pe)

CALL SHMEM_CHARACTER_PUT_NBI(dest, source, nelems, pe)

CALL SHMEM_COMPLEX_PUT_NBI(dest, source, nelems, pe)

CALL SHMEM_DOUBLE_PUT_NBI(dest, source, nelems, pe)

CALL SHMEM_INTEGER_PUT_NBI(dest, source, nelems, pe)

CALL SHMEM_LOGICAL_PUT_NBI(dest, source, nelems, pe)

CALL SHMEM_REAL_PUT_NBI(dest, source, nelems, pe)

CALL SHMEM_PUT4_NBI(dest, source, nelems, pe)

CALL SHMEM_PUT8_NBI(dest, source, nelems, pe)

CALL SHMEM_PUT32_NBI(dest, source, nelems, pe)

CALL SHMEM_PUT64_NBI(dest, source, nelems, pe)

CALL SHMEM_PUT128_NBI(dest, source, nelems, pe)

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🌸 DESCRIPTION 🌸

so the way these work: the routines return right after posting the operation. they don't wait around, they're booked and busy. the operation is only considered complete after a subsequent call to shmem_quiet. and at the completion of shmem_quiet, the data has been copied into the dest array on the destination PE. 🫡

here's the spicy part, lowkey: the delivery of data words into the data object on the destination PE may occur in any order. and worse (derogatory) — two successive put routines may deliver data out of order unless a call to shmem_fence is introduced between the two calls. so if ordering matters to you, bestie, shmem_fence is not optional, it's the whole plot 🙈

The arguments are as follows:

• dest — the data object to be updated on the remote PE. This data object must be remotely accessible. no exceptions ✋
• source — the data object containing the data to be copied.
• nelems — number of elements in the dest and source arrays. nelems must be of type size_t for C. If you're in Fortran, it has to be a constant, variable, or array element of default integer type.
• pe — PE number of the remote PE. pe must be of type integer. If you're in Fortran, it must be a constant, variable, or array element of default integer type.

If you are using Fortran, data types must be of default size. For example, a real variable must be declared as REAL, REAL*4, or REAL(KIND=4). don't be out here getting creative with kinds, it's giving chaos 🌈

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🎀 NOTES 🎀

See intro_shmem(3) for a definition of the term remotely accessible. iykyk, but if you don't, go read that one 💜

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🦋 EXAMPLES 🦋

Consider this simple example for C.

#include <stdio.h>
#include <mpp/shmem.h>

main()
{
  long source[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
  static long target[10];
  shmem_init();

  if (shmem_my_pe() == 0) {
    /* put 10 words into target on PE 1 */
    shmem_long_put_nbi(target, source, 10, 1);
    shmem_quiet();
  }
  shmem_barrier_all();  /* sync sender and receiver */
  if (shmem_my_pe() == 1)
    shmem_udcflush();  /* not required on Altix systems */
  printf("target[0] on PE %d is %d\n", shmem_my_pe(), target[0]);
}

like… shmem_quiet() after the put? that's the moment. that's the main character moment 🫶

See also: intro_shmem(3) shmem_quiet(3)

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ngl bestie, bookmark shmem_quiet(3) and intro_shmem(3), you're gonna need both 😭

and that's the page!! copyright 2003-2026, The Open MPI Community — dated Sep 10, 2026, from your friends over at Open MPI. slay, go put some bytes on a remote PE responsibly 💖✨👑