SHMEM_PUTMEM(3)

💖 SHMEM_PUTMEM(3) — Open MPI 💖

okay bestie, welcome to the Open MPI manual page for shmem_putmem and its whole ✨extended family✨. This is the one that teaches you how to yeet data across the parallel universe to another PE. Let's go 🫶

This page covers all of these iconic functions:

shmem_character_put(3), shmem_complex_put(3), shmem_double_put(3), shmem_float_put(3), shmem_int_put(3), shmem_integer_put(3), shmem_logical_put(3), shmem_long_put(3), shmem_longdouble_put(3), shmem_longlong_put(3), shmem_put4(3), shmem_put8(3), shmem_put32(3), shmem_put64(3), shmem_put128(3), shmem_putmem(3), shmem_real_put(3), shmem_short_put(3)

🌸 NAME 🌸

Transfers data to a specified processing element (PE). literally that's the whole job, and it does it slayfully 💅

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✨ SYNOPSIS ✨

C or C++:

#include <mpp/shmem.h>

void shmem_double_put(double *target, const double *source,
  size_t len, int pe)

void shmem_float_put(float *target, const float *source,
  size_t len, int pe)

void shmem_int_put(int *target, const int *source, size_t len,
  int pe)

void shmem_long_put(long *target, const long *source,
  size_t len, int pe)

void shmem_longdouble_put(long double *target,
  const long double *source, size_t len, int pe)

void shmem_longlong_put(long long *target,
  const long long *source, size_t len, int pe)

void shmem_put32(void *target, const void *source, size_t len,
  int pe)

void shmem_put64(void *target, const void *source, size_t len,
  int pe)

void shmem_put128(void *target, const void *source, size_t len,
  int pe)

void shmem_putmem(void *target, const void *source, size_t len,
  int pe)

void shmem_short_put(short *target, const short *source,
  size_t len, int pe)

Fortran:

INCLUDE "mpp/shmem.fh"

INTEGER len, pe

CALL SHMEM_CHARACTER_PUT(target, source, len, pe)

CALL SHMEM_COMPLEX_PUT(target, source, len, pe)

CALL SHMEM_DOUBLE_PUT(target, source, len, pe)

CALL SHMEM_INTEGER_PUT(target, source, len, pe)

CALL SHMEM_LOGICAL_PUT(target, source, len, pe)

CALL SHMEM_PUT(target, source, len, pe)

CALL SHMEM_PUT4(target, source, len, pe)

CALL SHMEM_PUT8(target, source, len, pe)

CALL SHMEM_PUT32(target, source, len, pe)

CALL SHMEM_PUT64(target, source, len, pe)

CALL SHMEM_PUT128(target, source, len, pe)

CALL SHMEM_PUTMEM(target, source, len, pe)

CALL SHMEM_REAL_PUT(target, source, len, pe)

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🦋 DESCRIPTION 🦋

okay so here's the vibe: these routines transfer nelems elements of the data object at address source on the calling PE over to the data object at address target on the remote PE pe. 🚀

and here's the part u NEED to know: these routines start the remote transfer, and they may return before the data is actually delivered to the remote PE. it's giving "fire and forget", bestie 😭

The delivery of data into the data object on the destination PE from different put calls may occur in any order. Because of this, two successive put operations may deliver data out of order unless a call to shmem_fence(3) is introduced between the two calls. so if ordering matters to u, fence it up, no cap 🚧

🎀 The arguments (aka the cast of characters)

• target — the data object to be updated on the remote PE. This data object must be remotely accessible. non-negotiable, bestie 💅
• source — the data object containing the data to be copied. the original. the blueprint. the main character.
• len — number of elements in the target and source arrays. len must be of type integer. If you are using 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 are using Fortran, it must be a constant, variable, or array element of default integer type. 🌈

🧚 Typing constraints (the vibe check your data has to pass)

The target and source data objects must conform to certain typing constraints, which are as follows:

• shmem_putmem — Fortran: any noncharacter type. C: any data type. len is scaled in bytes.
• shmem_put4, shmem_put32 — any noncharacter type that has a storage size equal to 32 bits.
• shmem_put8, shmem_put64 — any noncharacter type that has a storage size equal to 64 bits.
• shmem_put128 — any noncharacter type that has a storage size equal to 128 bits.
• shmem_short_put — elements of type short.
• shmem_int_put — elements of type int.
• shmem_long_put — elements of type long.
• shmem_longlong_put — elements of type long long.
• shmem_float_put — elements of type float.
• shmem_double_put — elements of type double.
• shmem_longdouble_put — elements of type long double.
• SHMEM_CHARACTER_PUT — elements of type character. len is the number of characters to transfer. The actual character lengths of the source and target variables are ignored. 🙈
• SHMEM_COMPLEX_PUT — elements of type complex of default size.
• SHMEM_DOUBLE_PUT — (Fortran) elements of type double precision.
• SHMEM_INTEGER_PUT — elements of type integer.
• SHMEM_LOGICAL_PUT — elements of type logical.
• SHMEM_REAL_PUT — elements of type real.

⚠️ 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). do not come in here with your custom-sized nonsense, bestie 💀

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🍓 EXAMPLES 🍓

The following shmem_put example is for C/C++ programs:

#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(target, source, 10, 1);
  }
  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 look at PE 0 putting all ten words into PE 1's target and then everyone meeting up at the barrier so nobody's left on read 😭🫶 iconic behavior honestly.

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👑 SEE ALSO 👑

intro_shmem(3) shmem_iput(3) shmem_quiet(3)

go read those too, iykyk 📚✨

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💜 COPYRIGHT 💜

2003-2026, The Open MPI Community

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and that's the whole page, bestie! 🎀✨ this was brought to you by the Open MPI crew, copyright 2003-2026, The Open MPI Community, dated May 14, 2026 — go forth and put your memory, slay 💅💖🦋