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<H1 id="MPI_Get_count">MPI_Get_count</H1>
Gets the number of "top level" elements
<H2>Synopsis</H2>
<PRE>
int MPI_Get_count(const MPI_Status * status, MPI_Datatype datatype, int *count)
</PRE>
<H2>Input Parameters</H2>
<DL>
<DT><B>status </B> <DD> return status of receive operation (Status)
<DT><B>datatype </B> <DD> datatype of each receive buffer element (handle)
</DL>
<P>
<H2>Output Parameters</H2>
<DL>
<DT><B>count </B> <DD> number of received elements (integer)
Notes:
If the size of the datatype is zero, this routine will return a count of
zero. If the amount of data in <tt>status</tt> is not an exact multiple of the
size of <tt>datatype</tt> (so that <tt>count</tt> would not be integral), a <tt>count</tt> of
<tt>MPI_UNDEFINED</tt> is returned instead.
</DL>
<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_TYPE </B> <DD> Invalid datatype argument. Additionally, this error can
occur if an uncommitted MPI_Datatype (see <tt>MPI_Type_commit</tt>) is used
in a communication call.
</DL>
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