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Mmap ​

Creates a virtual-memory mapping.

Module: Illumos

Signature ​

rux
func Mmap(addr: *opaque, length: uint, prot: int32,
    flags: int32, fd: int32, offset: uint64) -> int64;

Parameters ​

NameTypeDescription
addr*opaqueRequested address hint, or null.
lengthuintMapping length in bytes.
protint32Page protections, such as PROT_READ.
flagsint32Mapping behavior, such as MAP_PRIVATE.
fdint32Backing descriptor, or -1 for anonymous memory.
offsetuint64Page-aligned offset in the backing object.

Returns ​

int64 - the mapped address encoded as an integer on success, or the thunk's raw error result on failure.

For a private anonymous mapping, combine MAP_PRIVATE | MAP_ANONYMOUS, pass -1i32 for fd, and use an offset of 0u64.

DANGER

Check the result before casting it to a pointer. Release every successful mapping with Munmap using the correct base address and length.

Example ​

rux
import Illumos::{ IsError, Mmap, Munmap, MAP_ANONYMOUS, MAP_PRIVATE, PROT_READ, PROT_WRITE };

let result = Mmap(null, 4096u, PROT_READ | PROT_WRITE,
    MAP_PRIVATE | MAP_ANONYMOUS, -1i32, 0u64);
if IsError(result) {
    return 1i32;
}
let memory = result as *opaque;
Munmap(memory, 4096u);

See also ​