sdgetv(2)                 SYSTEM CALLS                  sdgetv(2)



NAME
     sdgetv - synchronizes shared data access.

SYNOPSIS
     cc [flag ...] file ... -lx
     #include <sys/sd.h>

     int sdgetv(addr)
     int sdwaitv(char *addr, int vnum);

DESCRIPTION
     sdgetv and sdwaitv may be used  to  synchronize  cooperating
     processes  that  are using shared data segments.  The return
     value of both routines is the version number of  the  shared
     data  segment  attached to the process at address addr.  The
     version number of a segment changes  whenever  some  process
     does an sdleave for that segment.  sdgetv simply returns the
     version number of the indicated segment.  sdwaitv forces the
     current  process  to  sleep until the version number for the
     indicated segment is no longer equal to vnum.

DIAGNOSTICS
     Upon successful completion, both sdgetv and sdwaitv return a
     positive  integer that is the current version number for the
     indicated shared data segment.  Otherwise, a value of -1  is
     returned, and errno is set to indicate the error.

SEE ALSO
     sdenter(2), sdget(2).


























            Last change: XENIX Compatibility Package            1