mlock(3C)                                                  mlock(3C)


       NAME
             mlock, munlock - lock (or unlock) pages in memory

       SYNOPSIS
             #include <sys/types.h>
             #include <sys/mman.h>
             int mlock(caddr_t addr, size_t len);
             int munlock(caddr_t addr, size_t len);

       DESCRIPTION
             The function mlock uses the mappings established for the
             address range

                   [addr, addr + len)

             to identify pages to be locked in memory.  The effect of
                   mlock(addr, len)

             is equivalent to

                   memcntl(addr, len, MC_LOCK, 0, 0, 0)

             munlock removes locks established with mlock.  The effect of
                   munlock(addr, len)

             is equivalent to

                   memcntl(addr, len, MC_UNLOCK, 0, 0, 0)

             Locks established with mlock are not inherited by a child
             process after a fork and are not nested.

          Return Values
             Upon successful completion, the functions mlock and munlock
             return 0; otherwise, they return -1 and set errno to indicate
             the error.

       REFERENCES
             fork(2), memcntl(2), mlockall(3C), mmap(2), plock(2),
             sysconf(3C)

       NOTICES
             Use of mlock and munlock requires that the user have
             appropriate privileges.




                           Copyright 1994 Novell, Inc.               Page 1