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MPI_Win_shared_query(3)		      MPI	       MPI_Win_shared_query(3)

NAME
       MPI_Win_shared_query  -	Query the size and base	pointer	for a patch of
       a shared	memory window.

SYNOPSIS
       int MPI_Win_shared_query(MPI_Win	win, int rank, MPI_Aint	*size, int *disp_unit, void *baseptr)

       This function queries the process-local address for remote memory  seg-
       ments  created with MPI_Win_allocate_shared .  This function can	return
       different process-local addresses for the same physical memory on  dif-
       ferent processes.

       The  returned memory can	be used	for load/store accesses	subject	to the
       constraints defined in MPI 3.0, Section 11.7. This function can only be
       called with windows of type MPI_Win_flavor_shared .  If the passed win-
       dow is not of flavor MPI_Win_flavor_shared , the	error MPI_ERR_RMA_FLA-
       VOR is raised. When rank	is MPI_PROC_NULL , the pointer,	disp_unit, and
       size returned are the pointer, disp_unit, and size of the  memory  seg-
       ment  belonging	the  lowest  rank that specified size >	0. If all pro-
       cesses in the group attached to the window specified size = 0, then the
       call returns size = 0 and a baseptr as if MPI_Alloc_mem was called with
       size = 0.

INPUT PARAMETERS
       win    -	window object used for communication (handle)
       rank   -	target rank

OUTPUT PARAMETERS
       size   -	size of	the segment at the given rank
       disp_unit
	      -	local unit size	for displacements, in bytes (positive integer)
       baseptr
	      -	base pointer in	the calling  process'  address	space  of  the
	      shared segment belonging to the target rank.

THREAD AND INTERRUPT SAFETY
       This  routine  is  thread-safe.	 This  means  that this	routine	may be
       safely used by multiple threads without the need	for any	 user-provided
       thread  locks.  However,	the routine is not interrupt safe.  Typically,
       this is due to the use of memory	allocation routines such as malloc  or
       other  non-MPICH	 runtime  routines  that are themselves	not interrupt-
       safe.

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_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_WIN
	      -	Invalid	MPI window object

SEE ALSO
       MPI_Win_allocate_shared

				  11/10/2017	       MPI_Win_shared_query(3)

NAME | SYNOPSIS | INPUT PARAMETERS | OUTPUT PARAMETERS | THREAD AND INTERRUPT SAFETY | NOTES FOR FORTRAN | ERRORS | SEE ALSO

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