MPI_Waitall(3)                     Open MPI                     MPI_Waitall(3)



NAME
       MPI_Waitall - Waits for all given communications to complete.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Waitall(int count, MPI_Request *array_of_requests,
            MPI_Status *array_of_statuses)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_WAITALL(COUNT, ARRAY_OF_REQUESTS, ARRAY_OF_STATUSES, IERROR)
            INTEGER   COUNT, ARRAY_OF_REQUESTS(*)
            INTEGER   ARRAY_OF_STATUSES(MPI_STATUS_SIZE,*), IERROR


C++ Syntax
       #include <mpi.h>
       static void Request::Waitall(int count, Request array_of_requests[],
            Status array_of_statuses[])

       static void Request::Waitall(int count, Request array_of_requests[])


INPUT PARAMETERS
       count     Lists length (integer).

       array_of_requests
                 Array of requests (array of handles).


OUTPUT PARAMETERS
       array_of_statuses
                 Array of status objects (array of status).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       Blocks until all communication operations associated with active
       handles in the list complete, and returns the status of all these
       operations (this includes the case where no handle in the list is
       active). Both arrays have the same number of valid entries. The ith
       entry in array_of_statuses is set to the return status of the ith
       operation. Requests that were created by nonblocking communication
       operations are deallocated, and the corresponding handles in the array
       are set to MPI_REQUEST_NULL. The list may contain null or inactive
       handles. The call sets to empty the status of each such entry.

       The error-free execution of MPI_Waitall(count, array_of_requests,
       array_of_statuses) has the same effect as the execution of
       MPI_Wait(&array_of_request[i], &array_of_statuses[i]), for
       i=0,...,count-1, in some arbitrary order. MPI_Waitall with an array of
       length 1 is equivalent to MPI_Wait.

       When one or more of the communications completed by a call to
       MPI_Waitall fail, it is desirable to return specific information on
       each communication. The function MPI_Waitall will return in such case
       the error code MPI_ERR_IN_STATUS and will set the error field of each
       status to a specific error code. This code will be MPI_SUCCESS if the
       specific communication completed; it will be another specific error
       code if it failed; or it can be MPI_ERR_PENDING if it has neither
       failed nor completed. The function MPI_Waitall will return MPI_SUCCESS
       if no request had an error, or will return another error code if it
       failed for other reasons (such as invalid arguments). In such cases, it
       will not update the error fields of the statuses.

       If your application does not need to examine the array_of_statuses
       field, you can save resources by using the predefined constant
       MPI_STATUSES_IGNORE can be used as a special value for the
       array_of_statuses argument.


ERRORS
       For each invocation of MPI_Waitall, if one or more requests generate an
       MPI exception, only the first MPI request that caused an exception will
       be passed to its corresponding error handler.  No other error handlers
       will be invoked (even if multiple requests generated exceptions).
       However, all requests that generate an exception will have a relevant
       error code set in the corresponding status.MPI_ERROR field (unless
       MPI_IGNORE_STATUSES was used).

       The default error handler aborts the MPI job, except for I/O function
       errors. The error handler may be changed with MPI_Comm_set_errhandler,
       MPI_File_set_errhandler, or MPI_Win_set_errhandler (depending on the
       type of MPI handle that generated the MPI request); the predefined
       error handler MPI_ERRORS_RETURN may be used to cause error values to be
       returned. Note that MPI does not guarantee that an MPI program can
       continue past an error.

       If the invoked error handler allows MPI_Waitall to return to the
       caller, the value MPI_ERR_IN_STATUS will be returned in the C and
       Fortran bindings.  In C++, if the predefined error handler
       MPI::ERRORS_THROW_EXCEPTIONS is used, the value MPI::ERR_IN_STATUS will
       be contained in the MPI::Exception object.  The MPI_ERROR field can
       then be examined in the array of returned statuses to determine exactly
       which request(s) generated an exception.


SEE ALSO
       MPI_Comm_set_errhandler
       MPI_File_set_errhandler
       MPI_Test
       MPI_Testall
       MPI_Testany
       MPI_Testsome
       MPI_Wait
       MPI_Waitany
       MPI_Waitsome
       MPI_Win_set_errhandler




1.4.1                            Jan 14, 2010                   MPI_Waitall(3)
