plock(2)                  SYSTEM CALLS                   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)                  SYSTEM CALLS                   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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