jD91mZM2
31 lines
810 B
Rust
31 lines
810 B
Rust
use std::{
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fs::File,
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io,
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mem,
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os::unix::io::AsRawFd,
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thread,
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time::Duration
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};
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fn from_syscall_error(error: syscall::Error) -> io::Error {
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io::Error::from_raw_os_error(error.errno as i32)
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}
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fn main() -> Result<(), io::Error> {
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let file = File::open("shm:counter")?;
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println!("Reading from map... ");
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let counter = unsafe {
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&mut *(syscall::fmap(file.as_raw_fd() as usize, &syscall::Map {
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offset: 0,
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size: mem::size_of::<usize>(),
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flags: syscall::PROT_READ | syscall::PROT_WRITE
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}).map_err(from_syscall_error)? as *mut usize)
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};
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println!("Read value {}", counter);
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*counter += 1;
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println!("Increased value to {}", counter);
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loop {
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thread::sleep(Duration::from_secs(std::u64::MAX));
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}
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}
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