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RedHat 9 (Linux i386) - man page for mpi_waitall (redhat section 3)

MPI_Waitall(3)				     LAM/MPI				   MPI_Waitall(3)

       MPI_Waitall -  Waits for all given communications to complete

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

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

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

       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 argu-
       ment 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  excep-
       tions  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  MPI_Request  ;  either  null	or,  MPI_REQUEST_NULL  , in the case of a
	      MPI_Start or MPI_Startall , not a persistent request.
	      - 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.
	      - Invalid count argument.  Count arguments must be non-negative; a count of zero is
	      often valid.

	      - 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 argu-
	      ment, the actual error will be lost. This error class is	returned  only	from  the
	      multiple-completion routines ( MPI_Testall , MPI_Testany , MPI_Testsome , MPI_Wait-
	      all , 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
	      - 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.

       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 ftp://ftp.mcs.anl.gov/pub/sowing/sowing.tar.gz ), the  initial  for-
       matting, and some initial text for most of the MPI-1 man pages.


LAM/MPI 6.5.8				    11/10/2002				   MPI_Waitall(3)

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