diff options
Diffstat (limited to 'third_party/rust/parking_lot/src/deadlock.rs')
| -rw-r--r-- | third_party/rust/parking_lot/src/deadlock.rs | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/third_party/rust/parking_lot/src/deadlock.rs b/third_party/rust/parking_lot/src/deadlock.rs new file mode 100644 index 0000000000..0fab7228c9 --- /dev/null +++ b/third_party/rust/parking_lot/src/deadlock.rs @@ -0,0 +1,232 @@ +//! \[Experimental\] Deadlock detection +//! +//! This feature is optional and can be enabled via the `deadlock_detection` feature flag. +//! +//! # Example +//! +//! ``` +//! #[cfg(feature = "deadlock_detection")] +//! { // only for #[cfg] +//! use std::thread; +//! use std::time::Duration; +//! use parking_lot::deadlock; +//! +//! // Create a background thread which checks for deadlocks every 10s +//! thread::spawn(move || { +//! loop { +//! thread::sleep(Duration::from_secs(10)); +//! let deadlocks = deadlock::check_deadlock(); +//! if deadlocks.is_empty() { +//! continue; +//! } +//! +//! println!("{} deadlocks detected", deadlocks.len()); +//! for (i, threads) in deadlocks.iter().enumerate() { +//! println!("Deadlock #{}", i); +//! for t in threads { +//! println!("Thread Id {:#?}", t.thread_id()); +//! println!("{:#?}", t.backtrace()); +//! } +//! } +//! } +//! }); +//! } // only for #[cfg] +//! ``` + +#[cfg(feature = "deadlock_detection")] +pub use parking_lot_core::deadlock::check_deadlock; +pub(crate) use parking_lot_core::deadlock::{acquire_resource, release_resource}; + +#[cfg(test)] +#[cfg(feature = "deadlock_detection")] +mod tests { + use crate::{Mutex, ReentrantMutex, RwLock}; + use std::sync::{Arc, Barrier}; + use std::thread::{self, sleep}; + use std::time::Duration; + + // We need to serialize these tests since deadlock detection uses global state + static DEADLOCK_DETECTION_LOCK: Mutex<()> = crate::const_mutex(()); + + fn check_deadlock() -> bool { + use parking_lot_core::deadlock::check_deadlock; + !check_deadlock().is_empty() + } + + #[test] + fn test_mutex_deadlock() { + let _guard = DEADLOCK_DETECTION_LOCK.lock(); + + let m1: Arc<Mutex<()>> = Default::default(); + let m2: Arc<Mutex<()>> = Default::default(); + let m3: Arc<Mutex<()>> = Default::default(); + let b = Arc::new(Barrier::new(4)); + + let m1_ = m1.clone(); + let m2_ = m2.clone(); + let m3_ = m3.clone(); + let b1 = b.clone(); + let b2 = b.clone(); + let b3 = b.clone(); + + assert!(!check_deadlock()); + + let _t1 = thread::spawn(move || { + let _g = m1.lock(); + b1.wait(); + let _ = m2_.lock(); + }); + + let _t2 = thread::spawn(move || { + let _g = m2.lock(); + b2.wait(); + let _ = m3_.lock(); + }); + + let _t3 = thread::spawn(move || { + let _g = m3.lock(); + b3.wait(); + let _ = m1_.lock(); + }); + + assert!(!check_deadlock()); + + b.wait(); + sleep(Duration::from_millis(50)); + assert!(check_deadlock()); + + assert!(!check_deadlock()); + } + + #[test] + fn test_mutex_deadlock_reentrant() { + let _guard = DEADLOCK_DETECTION_LOCK.lock(); + + let m1: Arc<Mutex<()>> = Default::default(); + + assert!(!check_deadlock()); + + let _t1 = thread::spawn(move || { + let _g = m1.lock(); + let _ = m1.lock(); + }); + + sleep(Duration::from_millis(50)); + assert!(check_deadlock()); + + assert!(!check_deadlock()); + } + + #[test] + fn test_remutex_deadlock() { + let _guard = DEADLOCK_DETECTION_LOCK.lock(); + + let m1: Arc<ReentrantMutex<()>> = Default::default(); + let m2: Arc<ReentrantMutex<()>> = Default::default(); + let m3: Arc<ReentrantMutex<()>> = Default::default(); + let b = Arc::new(Barrier::new(4)); + + let m1_ = m1.clone(); + let m2_ = m2.clone(); + let m3_ = m3.clone(); + let b1 = b.clone(); + let b2 = b.clone(); + let b3 = b.clone(); + + assert!(!check_deadlock()); + + let _t1 = thread::spawn(move || { + let _g = m1.lock(); + let _g = m1.lock(); + b1.wait(); + let _ = m2_.lock(); + }); + + let _t2 = thread::spawn(move || { + let _g = m2.lock(); + let _g = m2.lock(); + b2.wait(); + let _ = m3_.lock(); + }); + + let _t3 = thread::spawn(move || { + let _g = m3.lock(); + let _g = m3.lock(); + b3.wait(); + let _ = m1_.lock(); + }); + + assert!(!check_deadlock()); + + b.wait(); + sleep(Duration::from_millis(50)); + assert!(check_deadlock()); + + assert!(!check_deadlock()); + } + + #[test] + fn test_rwlock_deadlock() { + let _guard = DEADLOCK_DETECTION_LOCK.lock(); + + let m1: Arc<RwLock<()>> = Default::default(); + let m2: Arc<RwLock<()>> = Default::default(); + let m3: Arc<RwLock<()>> = Default::default(); + let b = Arc::new(Barrier::new(4)); + + let m1_ = m1.clone(); + let m2_ = m2.clone(); + let m3_ = m3.clone(); + let b1 = b.clone(); + let b2 = b.clone(); + let b3 = b.clone(); + + assert!(!check_deadlock()); + + let _t1 = thread::spawn(move || { + let _g = m1.read(); + b1.wait(); + let _g = m2_.write(); + }); + + let _t2 = thread::spawn(move || { + let _g = m2.read(); + b2.wait(); + let _g = m3_.write(); + }); + + let _t3 = thread::spawn(move || { + let _g = m3.read(); + b3.wait(); + let _ = m1_.write(); + }); + + assert!(!check_deadlock()); + + b.wait(); + sleep(Duration::from_millis(50)); + assert!(check_deadlock()); + + assert!(!check_deadlock()); + } + + #[cfg(rwlock_deadlock_detection_not_supported)] + #[test] + fn test_rwlock_deadlock_reentrant() { + let _guard = DEADLOCK_DETECTION_LOCK.lock(); + + let m1: Arc<RwLock<()>> = Default::default(); + + assert!(!check_deadlock()); + + let _t1 = thread::spawn(move || { + let _g = m1.read(); + let _ = m1.write(); + }); + + sleep(Duration::from_millis(50)); + assert!(check_deadlock()); + + assert!(!check_deadlock()); + } +} |