<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN"> <HTML> <HEAD> <META NAME="GENERATOR" CONTENT="DOCTEXT"> <TITLE>MPI_Scatterv</TITLE> </HEAD> <BODY BGCOLOR="FFFFFF"> <A NAME="MPI_Scatterv"><H1>MPI_Scatterv</H1></A> Scatters a buffer in parts to all processes in a communicator <H2>Synopsis</H2> <PRE> int MPI_Scatterv( void *sendbuf, int *sendcnts, int *displs, MPI_Datatype sendtype, void *recvbuf, int recvcnt, MPI_Datatype recvtype, int root, MPI_Comm comm) </PRE> <H2>Input Parameters</H2> <DL> <DT><B>sendbuf </B><DD>address of send buffer (choice, significant only at <TT>root</TT>) <DT><B>sendcounts </B><DD>integer array (of length group size) specifying the number of elements to send to each processor <DT><B>displs </B><DD>integer array (of length group size). Entry <TT>i</TT> specifies the displacement (relative to sendbuf from which to take the outgoing data to process <TT>i</TT> <DT><B>sendtype </B><DD>data type of send buffer elements (handle) <DT><B>recvcount </B><DD>number of elements in receive buffer (integer) <DT><B>recvtype </B><DD>data type of receive buffer elements (handle) <DT><B>root </B><DD>rank of sending process (integer) <DT><B>comm </B><DD>communicator (handle) </DL> <P> <H2>Output Parameter</H2> <DL><DT><B>recvbuf </B> <DD> address of receive buffer (choice) </DL> <P> <H2>Thread and Interrupt Safety</H2> <P> This routine is thread-safe. This means that this routine may be safely used by multiple threads without the need for any user-provided thread locks. However, the routine is not interrupt safe. Typically, this is due to the use of memory allocation routines such as <TT>malloc </TT>or other non-MPICH runtime routines that are themselves not interrupt-safe. <P> <H2>Notes for Fortran</H2> All MPI routines in Fortran (except for <TT>MPI_WTIME</TT> and <TT>MPI_WTICK</TT>) have an additional argument <TT>ierr</TT> at the end of the argument list. <TT>ierr </TT>is an integer and has the same meaning as the return value of the routine in C. In Fortran, MPI routines are subroutines, and are invoked with the <TT>call</TT> statement. <P> All MPI objects (e.g., <TT>MPI_Datatype</TT>, <TT>MPI_Comm</TT>) are of type <TT>INTEGER </TT>in Fortran. <P> <H2>Errors</H2> <P> All MPI routines (except <TT>MPI_Wtime</TT> and <TT>MPI_Wtick</TT>) return an error value; C routines as the value of the function and Fortran routines in the last argument. Before the value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job. The error handler may be changed with <TT>MPI_Comm_set_errhandler</TT> (for communicators), <TT>MPI_File_set_errhandler</TT> (for files), and <TT>MPI_Win_set_errhandler</TT> (for RMA windows). The MPI-1 routine <TT>MPI_Errhandler_set</TT> may be used but its use is deprecated. The predefined error handler <TT>MPI_ERRORS_RETURN</TT> may be used to cause error values to be returned. Note that MPI does <EM>not</EM> guarentee that an MPI program can continue past an error; however, MPI implementations will attempt to continue whenever possible. <P> <DL><DT><B>MPI_SUCCESS </B> <DD> No error; MPI routine completed successfully. </DL> <DL><DT><B>MPI_ERR_COMM </B> <DD> Invalid communicator. A common error is to use a null communicator in a call (not even allowed in <TT>MPI_Comm_rank</TT>). </DL> <DL><DT><B>MPI_ERR_COUNT </B> <DD> Invalid count argument. Count arguments must be non-negative; a count of zero is often valid. </DL> <DL><DT><B>MPI_ERR_TYPE </B> <DD> Invalid datatype argument. May be an uncommitted MPI_Datatype (see <TT>MPI_Type_commit</TT>). </DL> <DL><DT><B>MPI_ERR_BUFFER </B> <DD> Invalid buffer pointer. Usually a null buffer where one is not valid. </DL> <P><B>Location:</B>scatterv.c<P> </BODY></HTML>