mlock(3C)                                                         mlock(3C)


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

   SYNOPSIS
         #include <sys/types.h>
         int mlock(caddrt addr, sizet len);
         int munlock(caddrt addr, sizet 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,
         MCLOCK, 0, 0, 0).

         munlock removes locks established with mlock.  The effect of
         munlock(addr, len) is equivalent to memcntl(addr, len, MCUNLOCK, 0,
         0, 0).

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

   RETURN VALUE
         Upon successful completion, the functions mlock and munlock return a
         value of 0; otherwise, they return a value of -1 and set errno to
         indicate an error.

   ERRORS
         See memcntl(2).

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

   SEE ALSO
         fork(2), memcntl(2), mmap(2), mlockall(3C), plock(2), sysconf(3C).


















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