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

LAM/MPI 7.1.4                                       6/24/2006                                     MPI_Waitall(3)