sdgetv(2)      UNIX System V(Application Compatibility Package)       sdgetv(2)


NAME
      sdgetv - synchronize 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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