plock(2)                         UNIX System V                         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).

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.




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plock(2)                         UNIX System V                         plock(2)


NOTES
      memcntl is the preferred interface to process locking.




















































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