SHMEM_PUTMEM_NBI(3)

💖 SHMEM_PUTMEM_NBI(3) 💖

okay bestie, gather round, because today we're talking about shmem_putmem_nbi(3) and its whole gorgeous extended family: 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), and shmem_put128_nbi(3). ✨

These are the nonblocking put routines, and the way that they work is: they give you a whole method for copying data from a contiguous local data object over to a data object on a PE you specify. no cap. 🫶

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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)

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 here's the vibe: these routines return right after posting the operation. that's the whole point, they don't wait around. 💅

the operation is considered complete only after a subsequent call to shmem_quiet. and like, at the completion of shmem_quiet, the data has been copied into the dest array on the destination PE. periodt. 👑

but ngl, there's a little chaos in the mix: the delivery of data words into the data object on the destination PE may occur in any order. and on top of that, two successive put routines may deliver data out of order unless you sneak a call to shmem_fence in between the two calls. so if ordering matters to you, bestie, fence it. 🙈

the arguments are as follows:

• dest — the data object to be updated on the remote PE. this one must be remotely accessible.
• source — the data object containing the data to be copied.
• nelems — the number of elements in the dest and source arrays. for C, nelems must be of type size_t. if you're in Fortran land, it must be a constant, variable, or array element of default integer type.
• pe — the PE number of the remote PE. pe must be of type integer. if you're using 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 get cute with it. 🎀

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💜 NOTES 💜

for the definition of the term remotely accessible, go read intro_shmem(3). it's giving essential reading, fr fr. 📚

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🌈 EXAMPLES 🌈

okay so consider this simple example for C. she's little but she eats. 🔥

#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]);
}

See also:

intro_shmem(3) shmem_quiet(3)

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👑 Copyright 👑

2003-2026, The Open MPI Community

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and that's the whole page, bestie!! slay 💖✨ this was brought to you by the Open MPI girlies, dated Sep 10, 2026, and it lives in section 3 of the manual — SHMEM_PUTMEM_NBI(3) forever and always. go forth and put your data nonblockingly, but remember to shmem_quiet before you trust that it landed. 🎀🦋💅