Interaction with other POSIX APIs
QNX SDP8.0Programmer's GuideDeveloper
Typed memory can interact with other POSIX APIs.
- rlimits
- The POSIX
setrlimit()
APIs provide the ability to set limits
on the virtual and physical memory that a process can consume.
Since typed memory operations may operate on normal RAM
(
sysram
) and will create mappings in the process's address space, they need to be taken into account when doing therlimit
accounting. In particular, the following rules apply:- Any mapping created by mmap() for typed memory objects is counted in the process's RLIMIT_VMEM or RLIMIT_AS limit.
- Typed memory never counts against RLIMIT_DATA.
- POSIX file-descriptor functions
- You can use the file descriptor that posix_typed_memory_open()
returns with selected POSIX fd-based calls, as follows:
- fstat(fd,..), which fills in the stat structure as it does for a shared memory object. The st_size field holds the size of the typed memory object. In earlier releases, it was used internally by the OS.
- close(fd) closes the file descriptor.
- dup() and dup2() duplicate the file handle.
- posix_mem_offset() behaves as documented in the POSIX specification.
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