Provided by: lam-mpidoc_7.1.4-6build1_all bug


       MPI_Testsome -  Tests for some given communications to complete


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


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


              - number of completed requests (integer)
              - array of indices of operations that completed (array of integers)
       stats  -  array  of status objects for operations that completed (array of Status), or the
              MPI constant MPI_STATUSES_IGNORE


       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.


       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.


       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.
              - No error; MPI routine completed successfully.
              - Invalid count argument.  Count arguments must be non-negative; a count of zero is
              often valid.
              - 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.

              -  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 .


       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).


       The  LAM  Team  would  like the thank the MPICH Team for the handy program to generate man
       pages  ("doctext"  from  ),  the   initial
       formatting, and some initial text for most of the MPI-1 man pages.