SHMEM_CHAR_PUT_NBI(3)

💖 SHMEM_CHAR_PUT_NBI(3) — the Open MPI girlies' nonblocking put page ✨

okay so bestie, this is the manual for a whole family of nonblocking put routines, and today's cover girl is shmem_char_put_nbi(3). she's part of a whole squad:

• 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)

and what do they all do? the nonblocking put routines provide a method for copying data from a contiguous local data object to a data object on a specified PE. periodt. 🫶

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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 besties, this one's for you:

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 after posting the operation. that's the whole "nonblocking" thing — they dip out immediately and let the network do its little thing behind the scenes. 💅

the operation is considered complete only after a subsequent call to shmem_quiet. once shmem_quiet finishes, the data has been copied into the dest array on the destination PE. simple as that.

lowkey important: the delivery of data words into the data object on the destination PE may occur in any order. not chaotic in a bad way, just... free-spirited. 🙈

and highkey important: two successive put routines may deliver data out of order unless a call to shmem_fence is introduced between the two calls. so if order matters to you, fence it up, bestie.

the arguments, explained 🎀

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

and for the Fortran girlies: 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 try to be cute with exotic kinds, she will not accept it. 💀

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📝 NOTES 📝

see intro_shmem(3) for a definition of the term remotely accessible. iykyk. 🧚

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🔥 EXAMPLES 🔥

consider this simple example for C. it's giving main character energy, honestly:

#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

and that's the whole page, bestie. this one was brought to you by the Open MPI girlies, dated Sep 10, 2026, filed under SHMEM_CHAR_PUT_NBI(3). slay, stay nonblocking, and always shmem_quiet before you read. 💖✨🦋