заблокировать или разблокировать диапазон адресного пространства процесса (РЕАЛЬНОЕ ВРЕМЯ) (lock or unlock a range of process address space (REALTIME))
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
mlock, munlock — lock or unlock a range of process address space
(REALTIME)
Синопсис (Synopsis)
#include <sys/mman.h>
int mlock(const void *addr, size_t len);
int munlock(const void *addr, size_t len);
Описание (Description)
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.
Appropriate privileges are required to lock process memory with
mlock().
Возвращаемое значение (Return value)
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.
Ошибки (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 appropriate privileges
to perform the requested operation.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
exec(1p), exit(3p), fork(3p), mlockall(3p), munmap(3p)
The Base Definitions volume of POSIX.1‐2017, sys_mman.h(0p)
