Man Linux: Main Page and Category List

NAME

       MPI_Waitall -  Waits for all given communications to complete

SYNOPSIS

       #include <mpi.h>
       int MPI_Waitall(int count, MPI_Request *reqs,
                      MPI_Status *stats)

INPUT PARAMETERS

       count  - lists length (integer)
       reqs   - array of requests (array of handles)

OUTPUT PARAMETER

       stats  -  array  of  status objects (array of Status), which may be the
              MPI constant MPI_STATUSES_IGNORE

NOTE ON STATUS FOR SEND OPERATIONS

       For send operations, the only use of status is  for  MPI_Test_cancelled
       in  the  case that there is an error, in which case the MPI_ERROR field
       of status will be set.

NOTES FOR FORTRAN

       All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK )  have
       an  additional  argument ierr at the end of the argument list.  ierr 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 call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
       Fortran.

ERRORS

       If an error occurs in an MPI function, the current MPI error handler is
       called to handle it.  By default, this error  handler  aborts  the  MPI
       job.   The  error  handler may be changed with MPI_Errhandler_set ; the
       predefined error handler MPI_ERRORS_RETURN may be used to  cause  error
       values  to  be  returned  (in C and Fortran; this error handler is less
       useful in with the C++ MPI  bindings.   The  predefined  error  handler
       MPI::ERRORS_THROW_EXCEPTIONS  should  be used in C++ if the error value
       needs to be recovered).  Note that MPI does not guarantee that  an  MPI
       program can continue past an error.

       All  MPI  routines  (except  MPI_Wtime  and MPI_Wtick ) return an error
       value; C routines as the value of the function and Fortran routines  in
       the  last  argument.   The  C++  bindings  for  MPI do not return error
       values; instead, error values are communicated by  throwing  exceptions
       of  type  MPI::Exception  (but  not  by  default).  Exceptions are only
       thrown if the error value is not MPI::SUCCESS .

       Note that if the MPI::ERRORS_RETURN handler is set in  C++,  while  MPI
       functions  will  return  upon an error, there will be no way to recover
       what the actual error value was.
       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_REQUEST
              - Invalid MPI_Request ; either null or,  MPI_REQUEST_NULL  ,  in
              the  case  of  a  MPI_Start  or  MPI_Startall , not a persistent
              request.
       MPI_ERR_ARG
              - Invalid  argument.   Some  argument  is  invalid  and  is  not
              identified  by a specific error class.  This is typically a NULL
              pointer or other such error.
       MPI_ERR_COUNT
              - Invalid count argument.  Count arguments must be non-negative;
              a count of zero is often valid.

       MPI_ERR_IN_STATUS
              -  The  actual  error value is in the MPI_Status argument.  Note
              that   if   this   error   occurs   and   MPI_STATUS_IGNORE   or
              MPI_STATUSES_IGNORE  was used as the status argument, the actual
              error will be lost. This error class is returned only  from  the
              multiple-completion  routines  (  MPI_Testall  ,  MPI_Testany  ,
              MPI_Testsome , MPI_Waitall , MPI_Waitany , and  MPI_Waitsome  ).
              The  field  MPI_ERROR  in the status argument contains the error
              value or MPI_SUCCESS (no error and complete) or  MPI_ERR_PENDING
              to  indicate  that  the  request  has  not  completed.   The MPI
              Standard does not  specify  what  the  result  of  the  multiple
              completion routines is when an error occurs.  For example, in an
              MPI_WAITALL , does the routine wait for all requests  to  either
              fail  or  complete,  or does it return immediately (with the MPI
              definition of immediately, which means independent of actions of
              other  MPI  processes)?   LAM/MPI  has chosen to make the return
              immediate (alternately, local in MPI  terms),  and  to  use  the
              error  class MPI_ERR_PENDING (introduced in MPI 1.1) to indicate
              which requests have not completed.   In  most  cases,  only  one
              request  with  an  error will be detected in each call to an MPI
              routine that tests multiple requests.  The  requests  that  have
              not  been  processed  (because  an  error  occured in one of the
              requests)  will  have  their   MPI_ERROR   field   marked   with
              MPI_ERR_PENDING .

       MPI_ERR_PENDING
              - Pending request (not an error).  See MPI_ERR_IN_STATUS .  This
              value indicates that the request  is  not  complete  nor  has  a
              encountered a detected error.

MORE INFORMATION

       For more information, please see the official MPI Forum web site, which
       contains the text  of  both  the  MPI-1  and  MPI-2  standards.   These
       documents contain detailed information about each MPI function (most of
       which is not duplicated in these man pages).

       http://www.mpi-forum.org/

ACKNOWLEDGEMENTS

       The LAM Team would like the thank the MPICH Team for the handy  program
       to        generate        man        pages        ("doctext"       from
       ftp://ftp.mcs.anl.gov/pub/sowing/sowing.tar.gz    ),    the     initial
       formatting, and some initial text for most of the MPI-1 man pages.

LOCATION

       waitall.c