plock(2)                                                           plock(2)


   NAME
         plock - lock into memory 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 super-user 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 are true:

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

         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 process.

         EAGAIN         Not enough memory.

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





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   plock(2)                                                           plock(2)


   DIAGNOSTICS
         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.














































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