mctl(3UCB) SunOS/BSD Compatibility Library Functions mctl(3UCB)NAMEmctl - memory management control
SYNOPSIS
/usr/ucb/cc [ flag ... ] file ...
#include <sys/types.h>
#include <sys/mman.h>
int mctl(addr, len, function, arg)
caddr_t addr;
size_t len;
int function;
int arg;
DESCRIPTIONmctl() applies a variety of control functions over pages identified by
the mappings established for the address range [addr, addr + len). The
function to be performed is identified by the argument function. Valid
functions are defined in mman.h as follows:
MC_LOCK Lock the pages in the range in memory. This function is
used to support mlock(). See mlock(3C) for semantics and
usage. arg is ignored.
MC_LOCKAS Lock the pages in the address space in memory. This
function is used to support mlockall(). See mlockall(3C)
for semantics and usage. addr and len are ignored. arg
is an integer built from the flags:
MCL_CURRENT Lock current mappings
MCL_FUTURE Lock future mappings
MC_SYNC Synchronize the pages in the range with their backing
storage. Optionally invalidate cache copies. This func‐
tion is used to support msync(). See msync(3C) for
semantics and usage. arg is used to represent the flags
argument to msync(). It is constructed from an OR of
the following values:
MS_SYNC Synchronized write
MS_ASYNC Return immediately
MS_INVALIDATE Invalidate mappings
MS_ASYNC returns after all I/O operations are scheduled.
MS_SYNC does not return until all I/O operations are
complete. Specify exactly one of MS_ASYNC or MS_SYNC.
MS_INVALIDATE invalidates all cached copies of data from
memory, requiring them to be re-obtained from the
object's permanent storage location upon the next refer‐
ence.
MC_UNLOCK Unlock the pages in the range. This function is used to
support munlock(). arg is ignored.
MC_UNLOCKAS Remove address space memory lock, and locks on all cur‐
rent mappings. This function is used to support
munlockall(). addr and len must have the value 0. arg is
ignored.
RETURN VALUESmctl() returns 0 on success, −1 on failure.
ERRORSmctl() fails if:
EAGAIN Some or all of the memory identified by the operation could
not be locked due to insufficient system resources.
EBUSY MS_INVALIDATE was specified and one or more of the pages is
locked in memory.
EINVAL addr is not a multiple of the page size as returned by getpa‐
gesize().
EINVAL addr and/or len do not have the value 0 when MC_LOCKAS or
MC_UNLOCKAS are specified.
EINVAL arg is not valid for the function specified.
EIO An I/O error occurred while reading from or writing to the
file system.
ENOMEM Addresses in the range [addr, addr + len) are invalid for the
address space of a process, or specify one or more pages
which are not mapped.
EPERM The process's effective user ID is not superuser and one of
MC_LOCK MC_LOCKAS, MC_UNLOCK, or MC_UNLOCKAS was specified.
SEE ALSOcc(1B), mmap(2), memcntl(2), getpagesize(3C), mlock(3C), mlockall(3C),
msync(3C)NOTES
Use of these interfaces should be restricted to only applications writ‐
ten on BSD platforms. Use of these interfaces with any of the system
libraries or in multi-thread applications is unsupported.
SunOS 5.10 30 Oct 2007 mctl(3UCB)
