Originální popis anglicky:
mlock, munlock - lock or unlock a range of process address space (
REALTIME)
Návod, kniha: POSIX Programmer's Manual
#include <sys/mman.h>
int mlock(const void *
addr, size_t
len );
int munlock(const void *
addr, size_t
len );
The
mlock() function shall cause those whole pages containing any part of
the address space of the process starting at address
addr and
continuing for
len bytes to be memory-resident until unlocked or until
the process exits or
execs another process image. The implementation
may require that
addr be a multiple of {PAGESIZE}.
The
munlock() function shall unlock those whole pages containing any part
of the address space of the process starting at address
addr and
continuing for
len bytes, regardless of how many times
mlock()
has been called by the process for any of the pages in the specified range.
The implementation may require that
addr be a multiple of {PAGESIZE}.
If any of the pages in the range specified to a call to
munlock() are
also mapped into the address spaces of other processes, any locks established
on those pages by another process are unaffected by the call of this process
to
munlock(). If any of the pages in the range specified by a call to
munlock() are also mapped into other portions of the address space of
the calling process outside the range specified, any locks established on
those pages via the other mappings are also unaffected by this call.
Upon successful return from
mlock(), pages in the specified range shall
be locked and memory-resident. Upon successful return from
munlock(),
pages in the specified range shall be unlocked with respect to the address
space of the process. Memory residency of unlocked pages is unspecified.
The appropriate privilege is required to lock process memory with
mlock().
Upon successful completion, the
mlock() and
munlock() functions
shall return a value of zero. Otherwise, no change is made to any locks in the
address space of the process, and the function shall return a value of -1 and
set
errno to indicate the error.
The
mlock() and
munlock() functions shall fail if:
- ENOMEM
- Some or all of the address range specified by the
addr and len arguments does not correspond to valid mapped
pages in the address space of the process.
The
mlock() function shall fail if:
- EAGAIN
- Some or all of the memory identified by the operation could
not be locked when the call was made.
The
mlock() and
munlock() functions may fail if:
- EINVAL
- The addr argument is not a multiple of {PAGESIZE}.
The
mlock() function may fail if:
- ENOMEM
- Locking the pages mapped by the specified range would
exceed an implementation-defined limit on the amount of memory that the
process may lock.
- EPERM
- The calling process does not have the appropriate privilege
to perform the requested operation.
The following sections are informative.
None.
None.
None.
None.
exec() ,
exit() ,
fork() ,
mlockall() ,
munmap() , the Base Definitions volume of
IEEE Std 1003.1-2001,
<sys/mman.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
