plock(2)                                                           plock(2)

NAME
     plock - lock or unlock process, text, or data

SYNOPSIS
     #include <sys/lock.h>

     int plock(int op);

DESCRIPTION
     plock() allows the calling process to lock into memory or unlock 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 superuser to use this call. plock() 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.

     plock() fails and does not perform the requested operation if one or
     more of the following apply:

     EPERM     The effective user ID of the calling process is not
               superuser.

     EINVAL    op is equal to PROCLOCK and a process lock, a text lock, or
               a data lock already exists on the calling process.

     EINVAL    op is equal to TXTLOCK and a text lock, or a process lock
               already exists on the calling process.

     EINVAL    op is equal to DATLOCK and a data lock, or a process lock
               already exists on the calling process.

     EINVAL    op is equal to UNLOCK and no lock exists on the calling pro-
               cess.

     EAGAIN    Not enough memory.

RESULT
     Upon successful completion, a value of 0 is returned to the calling
     process. Otherwise, a value of -1 is returned and errno is set to
     indicate the error.

NOTES
     memcntl is the preferred interface to process locking.




Page 1                       Reliant UNIX 5.44                Printed 11/98

plock(2)                                                           plock(2)

SEE ALSO
     exec(2), exit(2), fork(2), memcntl(2).




















































Page 2                       Reliant UNIX 5.44                Printed 11/98