SHMEM_DOUBLE_GET_NBI(3)

💖 NAME 💖

okay bestie, gather round, because this is a whole family of functions and they all do the same adorable thing: they're the nonblocking get routines ✨ and they give you a method for copying data from a contiguous remote data object on the specified PE to the local data object 🌸

the whole girl gang is:

• shmem_getmem_nbi(3)
• shmem_char_get_nbi(3)
• shmem_short_get_nbi(3)
• shmem_int_get_nbi(3)
• shmem_long_get_nbi(3)
• shmem_longlong_get_nbi(3)
• shmem_float_get_nbi(3)
• shmem_double_get_nbi(3)
• shmem_longdouble_get_nbi(3)
• shmem_get8_nbi(3)
• shmem_get16_nbi(3)
• shmem_get32_nbi(3)
• shmem_get64_nbi(3)
• shmem_get128_nbi(3)

and yes, they are so iconic for it 💅

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✨ SYNOPSIS ✨

🩷 C or C++

#include <mpp/shmem.h>

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

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

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

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

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

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

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

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

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

void shmem_get8(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_get16(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_get32(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_get64(void *dest, const void *source,
  size_t nelems, int pe)

void shmem_get128(void *dest, const void *source,
  size_t nelems, int pe)

🦋 Fortran

INCLUDE "mpp/shmem.fh"

INTEGER nelems, pe

CALL SHMEM_GETMEM_NBI(dest, source, nelems, pe)

CALL SHMEM_CHARACTER_GET_NBI(dest, source, nelems, pe)

CALL SHMEM_COMPLEX_GET_NBI(dest, source, nelems, pe)

CALL SHMEM_DOUBLE_GET_NBI(dest, source, nelems, pe)

CALL SHMEM_INTEGER_GET_NBI(dest, source, nelems, pe)

CALL SHMEM_LOGICAL_GET_NBI(dest, source, nelems, pe)

CALL SHMEM_REAL_GET_NBI(dest, source, nelems, pe)

CALL SHMEM_GET4_NBI(dest, source, nelems, pe)

CALL SHMEM_GET8_NBI(dest, source, nelems, pe)

CALL SHMEM_GET32_NBI(dest, source, nelems, pe)

CALL SHMEM_GET64_NBI(dest, source, nelems, pe)

CALL SHMEM_GET128_NBI(dest, source, nelems, pe)

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🌸 DESCRIPTION 🌸

so like, the get routines give you a method for copying a contiguous symmetric data object from a different PE over to a contiguous data object on the local PE 🫶

the plot twist (affectionate): these routines return right after posting the operation. not after it's done. like, they said "im on it" and walked away, main character energy 💅

the operation is considered complete only after a subsequent call to shmem_quiet. and at the completion of shmem_quiet, the data has been delivered to the dest array on the local PE. so shmem_quiet is literally the responsible friend who makes sure everyone actually showed up 🎀

🌈 the arguments, bestie

• dest — the local data object that's gonna get updated ✨
• source — the data object on the PE identified by pe that holds the data to be copied. this data object must be remotely accessible (iykyk, more on that in NOTES)
• nelems — number of elements in the target and source arrays. len must be of type integer. if you're in 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 in Fortran, it must be a constant, variable, or array element of default integer type 👑

heads up bestie 💀 if you're 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). no sneaky custom kinds, okay?

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📝 NOTES 📝

for a definition of the term remotely accessible, go check out intro_shmem(3). it's giving required reading fr fr 📚

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🍓 EXAMPLES 🍓

okay consider this simple example, but for Fortran 💜

PROGRAM REDUCTION
  REAL VALUES, SUM
  COMMON /C/ VALUES
  REAL WORK

  CALL START_PES(0) ! ALLOW ANY NUMBER OF PES
  VALUES = MY_PE() ! INITIALIZE IT TO SOMETHING
  CALL SHMEM_BARRIER_ALL
  SUM = 0.0
  DO I = 0,NUM_PES()-1
    CALL SHMEM_REAL_GET_NBI(WORK, VALUES, 1, I)
    CALL SHMEM_QUIET                ! wait for delivery
    SUM = SUM + WORK
  ENDDO
  PRINT *, 'PE ', MY_PE(), ' COMPUTED SUM=', SUM
  CALL SHMEM_BARRIER_ALL
END

look at that CALL SHMEM_QUIET just sitting there being the whole point of the example. the way that it waits for delivery 😭✨

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🎀 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 a wrap, bestie 🫶 this was the Open MPI edition of the SHMEM_DOUBLE_GET_NBI(3) page, dated Sep 10, 2026. go post some nonblocking gets and remember to shmem_quiet afterwards or it literally never counts 🌟💅