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<TITLE>MPI_Type_create_struct</TITLE>
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<H1 id="MPI_Type_create_struct">MPI_Type_create_struct</H1>
Create an MPI datatype from a general set of datatypes, displacements, and block sizes
<H2>Synopsis</H2>
<PRE>
int MPI_Type_create_struct(int count,
const int array_of_blocklengths[],
const MPI_Aint array_of_displacements[],
const MPI_Datatype array_of_types[], MPI_Datatype * newtype)
</PRE>
<H2>Input Parameters</H2>
<DL>
<DT><B>count </B> <DD> number of blocks (integer) --- also number of entries in arrays
array_of_types, array_of_displacements and array_of_blocklengths
<DT><B>array_of_blocklengths </B> <DD> number of elements in each block (array of integer)
<DT><B>array_of_displacements </B> <DD> byte displacement of each block (array of address integer)
<DT><B>array_of_types </B> <DD> type of elements in each block (array of handles to
datatype objects)
</DL>
<P>
<H2>Output Parameters</H2>
<DL>
<DT><B>newtype </B> <DD> new datatype (handle)
</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_ARG </B> <DD> Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., <tt>MPI_ERR_RANK</tt>).
</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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