GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  MPI_SENDRECV (3)

NAME

MPI_Sendrecv - Sends and receives a message.

CONTENTS

Syntax
C Syntax
Fortran Syntax
C++ Syntax
Input Parameters
Output Parameters
Description
Errors
See Also

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Sendrecv(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
        int dest, int sendtag, void *recvbuf, int recvcount,
        MPI_Datatype recvtype, int source, int recvtag,
        MPI_Comm comm, MPI_Status *status)

Fortran Syntax

INCLUDE ’mpif.h’
MPI_SENDRECV(SENDBUF, SENDCOUNT, SENDTYPE, DEST, SENDTAG,
                RECVBUF, RECVCOUNT, RECVTYPE, SOURCE, RECVTAG, COMM,
                STATUS, IERROR)
        <type>  SENDBUF(*), RECVBUF(*)
        INTEGER SENDCOUNT, SENDTYPE, DEST, SENDTAG
        INTEGER RECVCOUNT, RECVTYPE, SOURCE, RECVTAG, COMM
        INTEGER STATUS(MPI_STATUS_SIZE), IERROR

C++ Syntax

#include <mpi.h>
void Comm::Sendrecv(const void *sendbuf, int sendcount, const
        Datatype& sendtype, int dest, int sendtag, void *recvbuf,
        int recvcount, const Datatype& recvtype, int source,
        int recvtag, Status& status) const

void Comm::Sendrecv(const void *sendbuf, int sendcount, const         Datatype& sendtype, int dest, int sendtag, void *recvbuf,         int recvcount, const Datatype& recvtype, int source,         int recvtag) const

INPUT PARAMETERS

sendbuf Initial address of send buffer (choice).
sendcount Number of elements to send (integer).
sendtype Type of elements in send buffer (handle).
dest Rank of destination (integer).
sendtag Send tag (integer).
recvcount Maximum number of elements to receive (integer).
recvtype Type of elements in receive buffer (handle).
source Rank of source (integer).
recvtag Receive tag (integer).
comm Communicator (handle).

OUTPUT PARAMETERS

recvbuf Initial address of receive buffer (choice).
status Status object (status). This refers to the receive operation.
IERROR Fortran only: Error status (integer).

DESCRIPTION

The send-receive operations combine in one call the sending of a message to one destination and the receiving of another message, from another process. The two (source and destination) are possibly the same. A send-receive operation is useful for executing a shift operation across a chain of processes. If blocking sends and receives are used for such a shift, then one needs to order the sends and receives correctly (for example, even processes send, then receive; odd processes receive first, then send) in order to prevent cyclic dependencies that may lead to deadlock. When a send-receive operation is used, the communication subsystem takes care of these issues. The send-receive operation can be used in conjunction with the functions described in Chapter 6 of the MPI-1 Standard, "Process Topologies," in order to perform shifts on various logical topologies. Also, a send-receive operation is useful for implementing remote procedure calls.

A message sent by a send-receive operation can be received by a regular receive operation or probed by a probe operation; a send-receive operation can receive a message sent by a regular send operation.

MPI_Sendrecv executes a blocking send and receive operation. Both send and receive use the same communicator, but possibly different tags. The send buffer and receive buffers must be disjoint, and may have different lengths and datatypes.

If your application does not need to examine the status field, you can save resources by using the predefined constant MPI_STATUS_IGNORE as a special value for the status argument.

ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

SEE ALSO

MPI_Sendrecv_replace

Search for    or go to Top of page |  Section 3 |  Main Index


1.10.2 MPI_SENDRECV (3) Jan 21, 2016

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.