MLOCKALL(3C) Standard C Library Functions MLOCKALL(3C)
NAME
mlockall, munlockall - lock or unlock address space
SYNOPSIS
#include <sys/mman.h>
int mlockall(
int flags);
int munlockall(
void);
DESCRIPTION
The
mlockall() function locks in memory all pages mapped by an
address space.
The value of
flags determines whether the pages to be locked are
those currently mapped by the address space, those that will be
mapped in the future, or both:
MCL_CURRENT Lock current mappings
MCL_FUTURE Lock future mappings
If
MCL_FUTURE is specified for
mlockall(), mappings are locked as
they are added to the address space (or replace existing mappings),
provided sufficient memory is available. Locking in this manner is
not persistent across the
exec family of functions (see
exec(2)).
Mappings locked using
mlockall() with any option may be explicitly
unlocked with a
munlock() call (see
mlock(3C)).
The
munlockall() function removes address space locks and locks on
mappings in the address space.
All conditions and constraints on the use of locked memory that apply
to
mlock(3C) also apply to
mlockall().
Locks established with
mlockall() are not inherited by a child
process after a
fork(2) call, and are not nested.
RETURN VALUES
Upon successful completion, the
mlockall() and
munlockall() functions return
0. Otherwise, they return
-1 and set
errno to
indicate the error.
ERRORS
The
mlockall() and
munlockall() functions will fail if:
EAGAIN Some or all of the memory in the address space could not be
locked due to sufficient resources. This error condition
applies to
mlockall() only.
EINVAL The
flags argument contains values other than
MCL_CURRENT and
MCL_FUTURE.
EPERM The {
PRIV_PROC_LOCK_MEMORY} privilege is not asserted in
the effective set of the calling process.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
exec(2),
fork(2),
memcntl(2),
mmap(2),
mlock(3C),
plock(3C),
sysconf(3C),
attributes(7),
standards(7) March 22, 2004 MLOCKALL(3C)
