PLOCK(2) PLOCK(2)
NAME
plock - lock process, text, or data in memory
SYNOPSIS
#include <sys/lock.h>
int plock (op)
int op;
DESCRIPTION
plock allows the calling process to lock its text segment
(text lock), its data segment (data lock), or both its text
and data segments (process lock) into memory. Locked
segments are immune to all routine swapping. plock also
allows these segments to be unlocked. The effective user ID
of the calling process must be super-user to use this call.
Op specifies the following:
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 will fail and 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
Page 1 May 1989
PLOCK(2) PLOCK(2)
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 type of lock
exists on the calling process.
[EAGAIN] Not enough memory.
SEE ALSO
exec(2), exit(2), fork(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.
Page 2 May 1989