Red Bear OS
28 lines
873 B
Rust
28 lines
873 B
Rust
use std::{fs::File, io, mem, os::unix::io::AsRawFd, thread, time::Duration};
|
|
|
|
fn from_syscall_error(error: syscall::Error) -> io::Error {
|
|
io::Error::from_raw_os_error(error.errno as i32)
|
|
}
|
|
fn main() -> Result<(), io::Error> {
|
|
let file = File::open("shm:counter")?;
|
|
println!("Reading from map... ");
|
|
let counter = unsafe {
|
|
&mut *(syscall::fmap(
|
|
file.as_raw_fd() as usize,
|
|
&syscall::Map {
|
|
offset: 0,
|
|
address: 0,
|
|
size: mem::size_of::<usize>(),
|
|
flags: syscall::PROT_READ | syscall::PROT_WRITE | syscall::MAP_SHARED,
|
|
},
|
|
)
|
|
.map_err(from_syscall_error)? as *mut usize)
|
|
};
|
|
println!("Read value {}", counter);
|
|
*counter += 1;
|
|
println!("Increased value to {}", counter);
|
|
|
|
thread::sleep(Duration::from_secs(1));
|
|
Ok(())
|
|
}
|