PLOCK(3C) Standard C Library Functions PLOCK(3C)
NAME
plock - lock or unlock into memory process, text, or data
SYNOPSIS
#include <sys/lock.h>
int plock(
int op);
DESCRIPTION
The
plock() function allows the calling process to lock or unlock into
memory 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.
The
plock() function 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.
RETURN VALUES
Upon successful completion,
0 is returned. Otherwise,
-1 is returned and
errno is set to indicate the error.
ERRORS
The
plock() function fails and does not perform the requested operation
if:
EAGAIN Not enough memory.
EINVAL The
op argument is equal to
PROCLOCK and a process lock, a text
lock, or a data lock already exists on the calling process; the
op argument is equal to
TXTLOCK and a text lock or a process
lock already exists on the calling process; the
op argument is
equal to
DATLOCK and a data lock or a process lock already
exists on the calling process; or the
op argument is equal to
UNLOCK and no lock exists on the calling process.
EPERM The {
PRIV_PROC_LOCK_MEMORY} privilege is not asserted in the
effective set of the calling process.
USAGE
The
mlock(3C) and
mlockall(3C) functions are the preferred interfaces for
process locking.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | MT-Safe |
+---------------+-----------------+
SEE ALSO
exec(2),
exit(2),
fork(2),
memcntl(2),
mlock(3C),
mlockall(3C),
attributes(7) March 22, 2004
PLOCK(3C)