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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)

       This function compares one element of type datatype in the compare buf-
       fer compare_addr	with the buffer	at offset target_disp  in  the	target
       window  specified  by target_rank and win and replaces the value	at the
       target with the value in	the origin buffer origin_addr if  the  compare
       buffer  and  the	target buffer are identical. The original value	at the
       target is returned in the buffer	result_addr.

INPUT PARAMETERS
       origin_addr
	      -	initial	address	of buffer (choice)
       compare_addr
	      -	initial	address	of compare buffer (choice)
       result_addr
	      -	initial	address	of result buffer (choice)
       datatype
	      -	datatype of the	entry in origin, result,  and  target  buffers
	      (handle)
       target_rank
	      -	rank of	target (nonnegative integer)
       target_disp
	      -	 displacement from start of window to beginning	of target buf-
	      fer (non-negative	integer)
       win    -	window object (handle)

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 dis-
       joint.

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 com-
       municators), MPI_File_set_errhandler (for files),  and  MPI_Win_set_er-
       rhandler	 (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 guarentee	that an	MPI program can	continue  past
       an  error;  however, MPI	implementations	will attempt to	continue when-
       ever possible.

       MPI_SUCCESS
	      -	No error; MPI routine completed	successfully.
       MPI_ERR_ARG
	      -	Invalid	argument.  Some	argument is invalid and	is not identi-
	      fied by a	specific error class (e.g., MPI_ERR_RANK ).
       MPI_ERR_COUNT
	      -	Invalid	count argument.	 Count arguments must be non-negative;
	      a	count of zero is often valid.
       MPI_ERR_OP
	      -	Invalid	operation.  MPI	operations (objects of type  MPI_Op  )
	      must either be one of the	predefined operations (e.g., MPI_SUM )
	      or created with MPI_Op_create .

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

       MPI_ERR_TYPE
	      -	Invalid	datatype argument.  Additionally, this error can occur
	      if an uncommitted	MPI_Datatype (see MPI_Type_commit ) is used in
	      a	communication call.
       MPI_ERR_WIN
	      -	Invalid	MPI window object

				  11/10/2017	       MPI_Compare_and_swap(3)

NAME | SYNOPSIS | INPUT PARAMETERS | NOTES | NOTES FOR FORTRAN | ERRORS

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