mas_snap(3mas)                                        mas_snap(3mas)


       NAME
             mas_snap - take a snapshot of the metric segments for consumer
             use

       SYNOPSIS
             cc [options] file -lmas
             #include <mas.h>
             int mas_snap(int md);

       DESCRIPTION
             The function mas_snap takes a snapshot of the metric data
             segments.  The md argument is a metric descriptor returned
             from mas_open.

             If read access is being used, (mas_open was called with acc
             set to MAS_READ_ACCESS), the metric data segments are read
             into the snapshot buffer with the read system call.

             If memory mapped access is being used, (mas_open was called
             with acc set to MAS_MMAP_ACCESS), the metric data segments are
             copied from their memory mapped pages into the snapshot buffer
             with the memcpy library call.

             When read access is being used, mas_get_met and
             mas_get_met_snap both return the address of a metric instance
             within the snapshot buffer.  When memory mapped access is
             being used, mas_get_met returns the address of a metric
             instance within the memory mapped pages, and mas_get_met_snap
             returns the address to which the instance is copied within the
             snapshot buffer.

          Return Values
             On success, mas_snap returns 0.

             On failure, mas_snap returns -1 and sets mas_errno to identify
             the error.

          Errors
             MAS_INVALID_ARG - invalid metric descriptor
                   The metric descriptor, md does not correspond to a
                   metric registration file previously opened by mas_open.

             MAS_SYSERR - can't seek on metric segment
                   Read access was in use and the lseek system called
                   failed.



                           Copyright 1994 Novell, Inc.               Page 1

      mas_snap(3mas)                                        mas_snap(3mas)


            MAS_SYSERR - cannot read metric segment
                  Read access was in use and the read system called
                  failed.

      REFERENCES
            mas(3mas)










































                          Copyright 1994 Novell, Inc.               Page 2