plock(2)

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plock(2)
NAME
  plock - Lock the text and/or data segments of a process in memory

SYNOPSIS
  #include <sys/lock.h>

  int plock(
	  int opr );

PARAMETERS
  opr Specifies one of the following operations:

      PROCLOCK
	  Locks the text and data segments into memory.

      TXTLOCK
	  Locks the text segment into memory.

      DATLOCK
	  Locks the data segment into memory.

      UNLOCK
	  Removes locks.

DESCRIPTION
  The plock() function locks or unlocks a process's text segments, data
  segments, or both in physical memory. When locked, the physical pages
  containing the text or data segment will not be paged out.  It is an error
  to lock a segment that is already locked.

  The caller must have superuser privilege to use the plock() function.

  Note that memory acquired subsequent to a plock() call may or may not be
  locked in memory, depending on the specific acquisition method. Memory
  acquired by using the brk() or sbrk() function will be locked if the data
  segment was locked. Memory acquired by means of the mmap() or vm_allocate()
  function will not be locked.

RETURN VALUES
  Upon successful completion, a value of 0 (zero) is returned to the calling
  process. Otherwise, a value of -1 is returned and errno is set to indicate
  the error.

ERRORS
  If the plock() function fails, errno may be set to one of the following
  values:

  [EAGAIN]
      There are insufficient resources to perform the operation.

  [EINVAL]
      One of the following occurred:

	·  The opr parameter is PROCLOCK, but the text segment or the data
	   segment is already locked.

	·  The opr parameter is TXTLOCK, but the text segment is already
	   locked.

	·  The opr parameter is DATLOCK, but the data segment is already
	   locked.

	·  The opr parameter is UNLOCK, but neither the text segment nor the
	   data segment is locked.

  [EPERM]
      The caller does not have appropriate privilege.

SEE ALSO
  Functions: brk(2), mmap(2)
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