locktick provides the means to measure things like the average guard duration and wait time for different kinds of locks, just by substituting the applicable locks' imports.
use std::{thread, time::Duration};
use locktick::lock_snapshots;
fn print_active_guards() {
thread::spawn(|| {
loop {
let mut locks = lock_snapshots();
locks.sort_unstable_by(|l1, l2| l1.location.cmp(&l2.location));
// Check if any of the known guards are currently active.
if locks.iter().flat_map(|lock| lock.known_guards.values()).all(|g| g.num_active_uses() == 0) {
// It's possible that the program is halted for reasons different than a deadlock; print
// something in order to ensure that the lock accounting thread is operational at all times.
println!("there are no active guards");
} else {
println!("\nthere are active guards:");
// Traverse all the known locks.
for lock in locks {
// Collec the data on all the known guards of the given lock.
let mut active_guards = lock.known_guards.values().filter(|g| g.num_active_uses() != 0).collect::<Vec<_>>();
// Skip a lock if none of its known guards are currently active.
if active_guards.is_empty() {
continue;
}
active_guards.sort_unstable_by(|g1, g2| g1.location.cmp(&g2.location));
println!("{}:", lock.location);
// Traverse the known guards of the given lock.
for guard in &active_guards {
let location = &guard.location;
let kind = guard.kind;
let num_uses = guard.num_uses;
let avg_duration = guard.avg_duration();
let avg_wait_time = guard.avg_wait_time();
// Log the desired details.
println!(
"- {location} ({:?}): used {num_uses} time(s) so far; avg duration: {:?}; avg wait: {:?}",
kind, avg_duration, avg_wait_time
);
}
}
}
// Check for active guards every 1 second.
thread::sleep(Duration::from_secs(1));
}
});
}- the basic functionalities are complete
- API breakage can still happen
- some of the TODOs include additional tests, examples, and improvements to documentation