---
name: "MPIX_Comm_revoke.openmpi"
section: "3"
platform: "linux"
package: "openmpi-doc"
version: "5.0.7-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/MPIX_Comm_revoke.openmpi"
---

# MPIX\_Comm\_revoke.openmpi(3)

*MPIX\_Comm\_revoke* - Revoke a communicator, causing errors to be raised, at all ranks, for non-local operations on the communicator.

This is part of the User Level Fault Mitigation *ULFM extension*.

## SYNTAX

### C Syntax

```
#include <mpi.h>
#include <mpi-ext.h>
int MPIX_Comm_revoke(MPI_Comm comm)
```

### Fortran Syntax

```
USE MPI
USE MPI_EXT
! or the older form: INCLUDE 'mpif.h'
MPIX_COMM_REVOKE(COMM, IERROR)
     INTEGER COMM, IERROR
```

### Fortran 2008 Syntax

```
USE mpi_f08
USE mpi_ext_f08
MPIX_Comm_revoke(comm, ierror)
     TYPE(MPI_Comm), INTENT(IN) :: comm
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror
```

## INPUT PARAMETERS

- •

  **comm**: Communicator (handle).

## OUTPUT PARAMETERS

- •

  **ierror**: Fortran only: Error status (integer).

## DESCRIPTION

This function marks the communicator *comm* as revoked at all MPI processes in the groups (local and remote) associated with the communicator *comm*. This function is not collective and therefore does not have a matching call on remote MPI processes.

The documentation for *MPIX\_Comm\_is\_revoked* details the conditions for when a communicator becomes revoked locally, and what semantics apply on a revoked communicator. In summary, when a communicator is revoked, non-local operation raise an exception of class MPIX\_ERR\_REVOKED, except for select fault-tolerant operations.

## PROPAGATION OF THE REVOKED STATE AND ORDERING

The implementation propagates the revoked state in a fault-tolerant manner; thus, the communicator becomes revoked at all non-failed MPI processes belonging to *comm* despite failed processes.

There is no particular ordering between the revocation call at another process and the completion of operations at a local process, for example, a receive operation can raise an error of class MPIX\_ERR\_REVOKED, even if the send operation procedure is called before the revoke procedure at the sender.

## ERRORS

Almost all MPI routines return an error value; C routines as the return result of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI\_COMM\_SELF and will call the associated MPI error handler. When MPI\_COMM\_SELF is not initialized (i.e., before *MPI\_Init*/*MPI\_Init\_thread*, after *MPI\_Finalize*, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling *MPI\_Comm\_set\_errhandler* on MPI\_COMM\_SELF when using the World model, or the mpi\_initial\_errhandler CLI argument to mpiexec or info key to *MPI\_Comm\_spawn*/*MPI\_Comm\_spawn\_multiple*. If no other appropriate error handler has been set, then the MPI\_ERRORS\_RETURN error handler is called for MPI I/O functions and the MPI\_ERRORS\_ABORT error handler is called for all other MPI functions.

Open MPI includes three predefined error handlers that can be used:

- •

  **MPI\_ERRORS\_ARE\_FATAL** Causes the program to abort all connected MPI processes.

- •

  **MPI\_ERRORS\_ABORT** An error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if *MPI\_Abort* was called on that communicator. If called on a window or file, acts as if *MPI\_Abort* was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process.

- •

  **MPI\_ERRORS\_RETURN** Returns an error code to the application.

MPI applications can also implement their own error handlers by calling:

- •

  *MPI\_Comm\_create\_errhandler* then *MPI\_Comm\_set\_errhandler*

- •

  *MPI\_File\_create\_errhandler* then *MPI\_File\_set\_errhandler*

- •

  *MPI\_Session\_create\_errhandler* then *MPI\_Session\_set\_errhandler* or at *MPI\_Session\_init*

- •

  *MPI\_Win\_create\_errhandler* then *MPI\_Win\_set\_errhandler*

Note that MPI does not guarantee that an MPI program can continue past an error.

See the *MPI man page* for a full list of *MPI error codes*.

See the Error Handling section of the MPI-3.1 standard for more information.

**SEE ALSO:**

- •

  *MPIX\_Comm\_is\_revoked*

- •

  *MPIX\_Comm\_agree*

- •

  *MPIX\_Comm\_shrink*

## COPYRIGHT

2003-2025, The Open MPI Community