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MPI_Compare_and_swap(3) MPI MPI_Compare_and_swap(3)

NAME

MPI_Compare_and_swap - Perform one-sided atomic compare-and-swap.

SYNOPSIS



int MPI_Compare_and_swap(const void *origin_addr, const void *compare_addr,
void *result_addr, MPI_Datatype datatype,
int target_rank, MPI_Aint target_disp, MPI_Win win)










INPUT PARAMETERS



  

  
- initial address of buffer (choice)

  

  
- initial address of compare buffer (choice)

  

  
- datatype of the element in all buffers (handle)

  

  
- rank of target (non-negative integer)

  

  
- displacement from start of window to beginning of target buffer
      (non-negative integer)

  

  
- window object (handle)
    

  








OUTPUT PARAMETERS



  

  
- initial address of result buffer (choice)
    

  








NOTES


This operation is atomic with respect to other
    "accumulate" operations.


The parameter datatype must belong to one of the following
    categories of predefined datatypes: C integer, Fortran integer, Logical,
    Multi-language types, or Byte as specified in Section 5.9.2 on page 176. The
    origin and result buffers (origin_addr and result_addr) must be
  disjoint.








NOTES FOR FORTRAN


All MPI routines in Fortran (except for MPI_WTIME and
    MPI_WTICK ) have an additional argument ierr at the end of the
    argument list. ierr is an integer and has the same meaning as the
    return value of the routine in C. In Fortran, MPI routines are subroutines,
    and are invoked with the call statement.


All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are
    of type INTEGER in Fortran.








ERRORS


All MPI routines (except MPI_Wtime and MPI_Wtick )
    return an error value; C routines as the value of the function and Fortran
    routines in the last argument. Before the value is returned, the current MPI
    error handler is called. By default, this error handler aborts the MPI job.
    The error handler may be changed with MPI_Comm_set_errhandler (for
    communicators), MPI_File_set_errhandler (for files), and
    MPI_Win_set_errhandler (for RMA windows). The MPI-1 routine
    MPI_Errhandler_set may be used but its use is deprecated. 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; however, MPI implementations will
    attempt to continue whenever possible.





  

  
- No error; MPI routine completed successfully.

  

  
- Invalid argument. Some argument is invalid and is not identified by a
      specific error class (e.g., MPI_ERR_RANK ).

  

  
-

  

  
- Invalid source or destination rank. Ranks must be between zero and the
      size of the communicator minus one; ranks in a receive ( MPI_Recv ,
      MPI_Irecv , MPI_Sendrecv , etc.) may also be
      MPI_ANY_SOURCE .
    

  

  

  
- Invalid MPI window object

  

  
- Other error; use MPI_Error_string to get more information about
      this error code.
    

  









  

    2/9/2024