plock(3C)

NAME

     plock - lock or unlock into memory process, text, or data

SYNOPSIS

     #include <sys/lock.h>

     int plock(int op);

DESCRIPTION

     The plock() function allows the calling process to  lock  or
     unlock  into  memory  its text segment (text lock), its data
     segment (data lock), or both  its  text  and  data  segments
     (process  lock).  Locked  segments are immune to all routine
     swapping. The effective user ID of the calling process  must
     be super-user to use this call.

     The plock() function performs the function specified by op:

     PROCLOCK
           Lock text  and  data  segments  into  memory  (process
           lock).

     TXTLOCK
           Lock text segment into memory (text lock).

     DATLOCK
           Lock data segment into memory (data lock).

     UNLOCK
           Remove locks.

RETURN VALUES

     Upon successful completion, 0 is returned. Otherwise, -1  is
     returned and errno is set to indicate the error.

ERRORS

     The  plock()  function  fails  and  does  not  perform   the
     requested operation if:

     EAGAIN
           Not enough memory.

     EINVAL
           The op argument is equal to  PROCLOCK  and  a  process
           lock,  a  text  lock, or a data lock already exists on
           the calling process;  the  op  argument  is  equal  to
           TXTLOCK  and  a  text  lock  or a process lock already
           exists on the calling  process;  the  op  argument  is
           equal  to  DATLOCK  and  a data lock or a process lock
           already exists on the calling process; or the op argu-
           ment is equal to UNLOCK and no lock exists on the cal-
           ling process.

     EPERM The effective user  of  the  calling  process  is  not
           super-user.

USAGE

     The mlock(3C) and mlockall(3C) functions are  the  preferred
     interfaces for process locking.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|

SEE ALSO

     exec(2),   exit(2),    fork(2),    memcntl(2),    mlock(3C),
     mlockall(3C), attributes(5)