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NAME

       MPI_Testall -  Tests for the completion of all previously initiated requests

SYNOPSIS

       int MPI_Testall(int count, MPI_Request array_of_requests[], int *flag,
                      MPI_Status array_of_statuses[])

INPUT PARAMETERS

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

OUTPUT PARAMETERS

       flag   - True if all requests have completed; false otherwise (logical)
       array_of_statuses
              - array of status objects (array of Status).  May be MPI_STATUSES_IGNORE .

NOTES

       flag  is  true  only if all requests have completed.  Otherwise, flag is false and neither
       the array_of_requests nor the array_of_statuses is modified.

       If one or more of the requests completes with an error, MPI_ERR_IN_STATUS is returned.  An
       error  value  will be present is elements of array_of_status associated with the requests.
       Likewise, the MPI_ERROR field in the status elements associated with  requests  that  have
       successfully  completed  will  be  MPI_SUCCESS  .   Finally,  those requests that have not
       completed will have a value of MPI_ERR_PENDING .

       While it is possible to list a request handle more than once in  the  array_of_requests  ,
       such  an  action  is  considered  erroneous  and  may  cause the program to unexecpectedly
       terminate or produce incorrect results.

THREAD AND INTERRUPT SAFETY

       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
       malloc or other non-MPICH runtime routines that are themselves not interrupt-safe.

NOTES ON THE MPI_STATUS ARGUMENT

       The MPI_ERROR field of the status return is only set if the return from the MPI routine is
       MPI_ERR_IN_STATUS .  That error class is only returned by the routines that take an  array
       of  status  arguments ( MPI_Testall , MPI_Testsome , MPI_Waitall , and MPI_Waitsome ).  In
       all other cases, the value of the MPI_ERROR field in the status is unchanged.  See section
       3.2.5 in the MPI-1.1 specification for the exact text.

       For  send operations, the only use of status is for MPI_Test_cancelled or in the case that
       there is an  error  in  one  of  the  four  routines  that  may  return  the  error  class
       MPI_ERR_IN_STATUS  ,  in  which  case  the MPI_ERROR field of status will be set.  In that
       case, the value will be set  to  MPI_SUCCESS  for  any  send  or  receive  operation  that
       completed  successfully, or MPI_ERR_PENDING for any operation which has neither failed nor
       completed.

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

       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.  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  MPI_Comm_set_errhandler  (for
       communicators),  MPI_File_set_errhandler  (for files), and MPI_Win_set_errhandler (for RMA
       windows).  The MPI-1 routine MPI_Errhandler_set may be used but  its  use  is  deprecated.
       The  predefined  error  handler  MPI_ERRORS_RETURN may be used to cause error values to be
       returned.  Note that MPI does not guarentee that an  MPI  program  can  continue  past  an
       error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_IN_STATUS
              -  The  actual  error  value  is  in  the MPI_Status argument.  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)?  MPICH 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_REQUEST
              - Invalid MPI_Request .  Either null or, 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 (e.g., MPI_ERR_RANK ).

                                            11/12/2016                             MPI_Testall(3)