MPI_WIN_FREE(3) Open MPI MPI_WIN_FREE(3)

MPI_Win_free — Frees the window object and returns a null handle.

#include <mpi.h>
int MPI_Win_free(MPI_Win *win)

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_WIN_FREE(WIN, IERROR)
     INTEGER WIN, IERROR

USE mpi_f08
MPI_Win_free(win, ierror)
     TYPE(MPI_Win), INTENT(INOUT) :: win
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

•
win: Window object (handle).

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

MPI_Win_free frees the window object win and returns a null handle (equal to MPI_WIN_NULL). This collective call is executed by all processes in the group associated with win. It can be invoked by a process only after it has completed its involvement in RMA communications on window win, that is, the process has called MPI_Win_fence, or called MPI_Win_unlock to match a previous call to MPI_Win_lock. When the call returns, the window memory can be freed.

If the window was created through MPI_Win_allocate or MPI_Win_allocate_shared then the memory buffer allocated in that call will be freed when calling MPI_Win_free.

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:

  • MPI_Win_create
  • MPI_Win_allocate
  • MPI_Win_allocate_shared

2003-2024, The Open MPI Community

February 6, 2024