56 lines
1.6 KiB
Rust
56 lines
1.6 KiB
Rust
use std::io;
|
|
use std::sync::Mutex;
|
|
|
|
use crossbeam_channel as chan;
|
|
|
|
/// Signal notifications are sent via this channel.
|
|
static NOTIFY: Mutex<Option<chan::Sender<()>>> = Mutex::new(None);
|
|
|
|
/// Install global signal handlers for `SIGTERM` and `SIGINT`.
|
|
pub fn install(notify: chan::Sender<()>) -> io::Result<()> {
|
|
if let Ok(mut channel) = NOTIFY.try_lock() {
|
|
if channel.is_some() {
|
|
return Err(io::Error::new(
|
|
io::ErrorKind::AlreadyExists,
|
|
"signal handler is already installed",
|
|
));
|
|
}
|
|
*channel = Some(notify);
|
|
|
|
unsafe { _install() }?;
|
|
} else {
|
|
return Err(io::Error::new(
|
|
io::ErrorKind::WouldBlock,
|
|
"unable to install signal handler",
|
|
));
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
/// Install global signal handlers for `SIGTERM` and `SIGINT`.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// Calls `libc` functions safely.
|
|
unsafe fn _install() -> io::Result<()> {
|
|
if libc::signal(libc::SIGTERM, handler as libc::sighandler_t) == libc::SIG_ERR {
|
|
return Err(io::Error::last_os_error());
|
|
}
|
|
if libc::signal(libc::SIGINT, handler as libc::sighandler_t) == libc::SIG_ERR {
|
|
return Err(io::Error::last_os_error());
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
/// Called by `libc` when a signal is received.
|
|
extern "C" fn handler(sig: libc::c_int, _info: *mut libc::siginfo_t, _data: *mut libc::c_void) {
|
|
if sig != libc::SIGTERM && sig != libc::SIGINT {
|
|
return;
|
|
}
|
|
if let Ok(guard) = NOTIFY.try_lock() {
|
|
if let Some(c) = &*guard {
|
|
c.try_send(()).ok();
|
|
}
|
|
}
|
|
}
|