mlock()
QNX SDP8.0C Library ReferenceAPIDeveloper
Lock a range of process address space in physical memory
Synopsis:
#include <sys/mman.h>
int mlock(const void * addr,
size_t len);
Arguments:
- addr
- The starting address for the range of process address space.
- len
- The amount of the memory to lock, in bytes. There's no limit on the amount of memory that a process may lock, other than the amount of physical memory in the system.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
Note:
In this QNX OS release, all memory is locked
for the entire duration of the process, so this function does nothing
other than checking that the provided range is fully mapped and backed (see below).
The mlock() function causes the whole pages containing any part of the calling process's address space starting at address addr and continuing for len bytes to be memory-resident until unlocked or until the process exits or is replaced by an exec*() call.
Memory-resident is a term used to indicate that the addresses always reside in physical memory.
For more information, see
Memory management
in the Process Manager chapter of the System Architecture guide.
Returns:
0 on success, -1 on failure (errno is set).
Errors:
- ENOMEM
- The provided range is not fully mapped and backed.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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