shmem_quiet.openmpi(3)

Waits for completion of all outstanding remote writes issued by a

Section 3 openmpi-doc bookworm source

Description

SHMEM_QUIET

NAME

shmem_quiet(3) - Waits for completion of all outstanding remote writes issued by a processing element (PE).

SYNOPSIS

C or C++:
#include <mpp/shmem.h>

void shmem_quiet(void);

Fortran:
CALL SHMEM_QUIET

DESCRIPTION

shmem_quiet ensures ordering of put (remote write) operations. All put operations issued to any processing element (PE) prior to the call to shmem_quiet are guaranteed to be visible to all other PEs no later than any subsequent memory load or store, remote put or get, or synchronization operations that follow the call to shmem_quiet.

NOTES

shmem_quiet is most useful as a way of ensuring ordering of delivery of several put operations. For example, you might use shmem_quiet to await delivery of a block of data before issuing another put, which sets a completion flag on another PE.
shmem_quiet is not usually needed if shmem_barrier_all(3) or shmem_barrier(3) are called. The barrier routines all wait for the completion of outstanding remote writes (puts).

EXAMPLES

PROGRAM COMPFLAG
INCLUDE "mpp/shmem.fh"

INTEGER FLAG_VAR, ARRAY(100), RECEIVER, SENDER
COMMON/FLAG/FLAG_VAR
COMMON/DATA/ARRAY
INTRINSIC MY_PE

FLAG_VAR = 0
CALL SHMEM_BARRIER_ALL ! wait for FLAG_VAR to be initialized
SENDER = 0 ! PE 0 sends the data
RECEIVER = 1 ! PE 1 receives the data

IF (MY_PE() .EQ. 0) THEN
ARRAY = 33
CALL SHMEM_PUT(ARRAY, ARRAY, 100, RECEIVER) ! start sending data
CALL SHMEM_QUIET ! wait for delivery
CALL SHMEM_PUT(FLAG_VAR, 1, 1, RECEIVER) ! send completion flag
ELSE IF (MY_PE() .EQ. RECEIVER) THEN
CALL SHMEM_UDCFLUSH
CALL SHMEM_WAIT(FLAG_VAR, 0)
PRINT *,ARRAY ! ARRAY has been delivered
ENDIF
END