82081118d6
Signed-off-by: Fangcong Yin (fyin2@nd.edu) Convert MPI_File_write_ordered.3in - MPI_Free_mem.3in to md Signed-off-by: Fangcong Yin (fyin2@nd.edu) Convert MPI_File_write_ordered.3in - MPI_Free_mem.3in to md Signed-off_by: Fangcong Yin (fyin2@nd.edu)
104 строки
3.8 KiB
Markdown
104 строки
3.8 KiB
Markdown
# Name
|
|
|
|
`MPI_Finalize` - Terminates MPI execution environment.
|
|
|
|
# Syntax
|
|
|
|
## C Syntax
|
|
|
|
```c
|
|
#include <mpi.h>
|
|
|
|
int MPI_Finalize()
|
|
```
|
|
|
|
## Fortran Syntax
|
|
|
|
```fortran
|
|
USE MPI
|
|
! or the older form: INCLUDE 'mpif.h'
|
|
|
|
MPI_FINALIZE(IERROR)
|
|
INTEGER IERROR
|
|
```
|
|
|
|
## Fortran 2008 Syntax
|
|
|
|
```fortran
|
|
USE mpi_f08
|
|
|
|
MPI_Finalize(ierror)
|
|
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
|
|
```
|
|
|
|
# Output Parameter
|
|
|
|
* `IERROR` : Fortran only: Error status (integer).
|
|
|
|
# Description
|
|
|
|
This routine cleans up all MPI states. Once this routine is called, no
|
|
MPI routine (not even `MPI_Init`) may be called, except for
|
|
`MPI_Get_version`, `MPI_Initialized`, and `MPI_Finalized`. Unless there has
|
|
been a call to `MPI_Abort`, you must ensure that all pending
|
|
communications involving a process are complete before the process calls
|
|
`MPI_Finalize`. If the call returns, each process may either continue
|
|
local computations or exit without participating in further
|
|
communication with other processes. At the moment when the last process
|
|
calls `MPI_Finalize`, all pending sends must be matched by a receive, and
|
|
all pending receives must be matched by a send.
|
|
|
|
`MPI_Finalize` is collective over all connected processes. If no processes
|
|
were spawned, accepted, or connected, then this means it is collective
|
|
over `MPI_COMM_WORLD`. Otherwise, it is collective over the union of all
|
|
processes that have been and continue to be connected.
|
|
|
|
# Notes
|
|
|
|
All processes must call this routine before exiting. All processes will
|
|
still exist but may not make any further MPI calls. `MPI_Finalize`
|
|
guarantees that all local actions required by communications the user
|
|
has completed will, in fact, occur before it returns. However,
|
|
`MPI_Finalize` guarantees nothing about pending communications that have
|
|
not been completed; completion is ensured only by `MPI_Wait`, `MPI_Test,`
|
|
or `MPI_Request_free` combined with some other verification of completion.
|
|
|
|
For example, a successful return from a blocking communication operation
|
|
or from `MPI_Wait` or `MPI_Test` means that the communication is completed
|
|
by the user and the buffer can be reused, but does not guarantee that
|
|
the local process has no more work to do. Similarly, a successful return
|
|
from `MPI_Request_free` with a request handle generated by an `MPI_Isend`
|
|
nullifies the handle but does not guarantee that the operation has
|
|
completed. The `MPI_Isend` is complete only when a matching receive has
|
|
completed.
|
|
|
|
If you would like to cause actions to happen when a process finishes,
|
|
attach an attribute to `MPI_COMM_SELF` with a callback function. Then,
|
|
when `MPI_Finalize` is called, it will first execute the equivalent of an
|
|
`MPI_Comm_free` on `MPI_COMM_SELF`. This will cause the delete callback
|
|
function to be executed on all keys associated with `MPI_COMM_SELF` in an
|
|
arbitrary order. If no key has been attached to `MPI_COMM_SELF`, then no
|
|
callback is invoked. This freeing of `MPI_COMM_SELF` happens before any
|
|
other parts of MPI are affected. Calling `MPI_Finalized` will thus return
|
|
"false" in any of these callback functions. Once you have done this
|
|
with `MPI_COMM_SELF`, the results of `MPI_Finalize` are not specified.
|
|
|
|
# Errors
|
|
|
|
Almost all MPI routines return an error value; C routines as the value
|
|
of the function and Fortran routines in the last argument.
|
|
|
|
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_Init`(3)](MPI_Init.html)
|
|
[`MPI_Init_thread`(3)](MPI_Init_thread.html)
|
|
[`MPI_Initialized`(3)](MPI_Initialized.html)
|
|
[`MPI_Finalized`(3)](MPI_Finalized.html)
|