RFIO_LOCKF(3)						      Rfio Library Functions						     RFIO_LOCKF(3)

NAME

       rfio_lockf - provide record locking on files

SYNOPSIS

       #include <sys/types.h>
       #include "rfio_api.h"

       int rfio_lockf (int sd, int op, long siz);

       Under Linux, for large files:
       #define _LARGEFILE64_SOURCE
       #include <sys/types.h>
       #include "rfio_api.h"

       int rfio_lockf64 (int sd, int op, off64_t siz);

       For large files, under other systems:
       #include <sys/types.h>
       #include "rfio_api.h"

       int rfio_lockf64 (int sd, int op, off64_t siz);

DESCRIPTION

       rfio_lockf restricts access to regions of files to the calling process.

       sd is the file descriptor returned by a previous rfio_open.

       op specifies the action to be taken:

	      F_ULOCK	   unlock a region.

	      F_LOCK	   lock a region.

	      F_TLOCK	   test and lock a region.

	      F_TEST	   test a region for other locks.

       siz gives the size of the region to be locked, starting at the current file offset.

       rfio_lockf64 must be used for large files and uses an off64_t instead of a long to specify the size of the region to be locked.

RETURN VALUE

       This routine returns 0 if the operation was successful or -1 if the operation failed. In the latter case, serrno is set appropriately.

ERRORS

       EBADF	    sd is not a valid descriptor.

       EACCES	    The file region is locked and F_TEST or F_TLOCK was specified.

       EINVAL	    incorrect value for op or siz.

       SENOSHOST    Host unknown.

       SENOSSERV    Service unknown.

       SETIMEDOUT   Timed out.

       SECONNDROP   Connection closed by remote end.

       SECOMERR     Communication error.

SEE ALSO

       rfio_open(3)

AUTHOR

       LCG Grid Deployment Team

LCG
							   $Date: 2005/03/31 13:13:03 $ 					     RFIO_LOCKF(3)