|MPI_IBARRIER(comm , request)|
|IN comm||communicator (handle)|
|OUT request||communication request (handle)|
int MPI_Ibarrier(MPI_Comm comm, MPI_Request *request)
MPI_Ibarrier(comm, request, ierror)
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPI_IBARRIER(COMM, REQUEST, IERROR)
INTEGER COMM, REQUEST, IERROR
MPI_IBARRIER is a nonblocking version of MPI_BARRIER. By calling MPI_IBARRIER, a process notifies that it has reached the barrier. The call returns immediately, independent of whether other processes have called MPI_IBARRIER. The usual barrier semantics are enforced at the corresponding completion operation (test or wait), which in the intracommunicator case will complete only after all other processes in the communicator have called MPI_IBARRIER. In the intercommunicator case, it will complete when all processes in the remote group have called MPI_IBARRIER.
Advice to users.
A nonblocking barrier can be used to hide latency. Moving
independent computations between the MPI_IBARRIER and the
subsequent completion call can overlap the barrier latency and therefore
shorten possible waiting times. The semantic properties are also useful
when mixing collective operations and point-to-point messages.
( End of advice to users.)