MPI_Startall(3) Open MPI MPI_Startall(3)NAMEMPI_Startall - Starts a collection of requests.
SYNTAXC Syntax
#include <mpi.h>
int MPI_Startall(int count, MPI_Request array_of_requests[])
Fortran Syntax
INCLUDE 'mpif.h'
MPI_STARTALL(COUNT, ARRAY_OF_REQUESTS, IERROR)
INTEGER COUNT, ARRAY_OF_REQUESTS(*), IERROR
C++ Syntax
#include <mpi.h>
static void Prequest::Startall(int count, Prequest array_of_requests[])
INPUT PARAMETER
count List length (integer).
INPUT/OUTPUT PARAMETER
array_of_requests
Array of requests (array of handle).
OUTPUT PARAMETER
IERROR Fortran only: Error status (integer).
DESCRIPTION
Starts all communications associated with requests in
array_of_requests. A call to MPI_Startall(count, array_of_requests)
has the same effect as calls to MPI_Start (&array_of_requests[i]), exe‐
cuted for i=0 ,..., count-1, in some arbitrary order.
A communication started with a call to MPI_Start or MPI_Startall is
completed by a call to MPI_Wait, MPI_Test, or one of the derived func‐
tions MPI_Waitany, MPI_Testany, MPI_Waitall, MPI_Testall, MPI_Waitsome,
MPI_Testsome (these are described in Section 3.7.5 of the MPI-1 Stan‐
dard, "Multiple Completions"). The request becomes inactive after suc‐
cessful completion by such a call. The request is not deallocated, and
it can be activated anew by another MPI_Start or MPI_Startall call.
A persistent request is deallocated by a call to MPI_Request_free (see
Section 3.7.3 of the MPI-1 Standard, "Communication Completion").
The call to MPI_Request_free can occur at any point in the program
after the persistent request was created. However, the request will be
deallocated only after it becomes inactive. Active receive requests
should not be freed. Otherwise, it will not be possible to check that
the receive has completed. It is preferable, in general, to free
requests when they are inactive. If this rule is followed, then the
persistent communication request functions will be invoked in a
sequence of the form,
Create (Start Complete)* Free
where * indicates zero or more repetitions. If the same communication
object is used in several concurrent threads, it is the user's respon‐
sibility to coordinate calls so that the correct sequence is obeyed.
A send operation initiated with MPI_Start can be matched with any
receive operation and, likewise, a receive operation initiated with
MPI_Start can receive messages generated by any send operation.
ERRORS
Almost all MPI routines return an error value; C routines as the value
of the function and Fortran routines in the last argument. C++ func‐
tions do not return errors. If the default error handler is set to
MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
will be used to throw an MPI::Exception object.
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for
I/O function errors. The error handler may be changed with
MPI_Comm_set_errhandler; 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.
SEE ALSO
MPI_Bsend_init
MPI_Rsend_init
MPI_Send_init
MPI_Ssend_init
MPI_Recv_init
MPI_Start
MPI_Request_free
1.7.4 Feb 04, 2014 MPI_Startall(3)
