sdgetv(2)              (XENIX Compatibility Package)              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).























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