_ Git - rust-lightning/blob - lightning/src/sync/mod.rs

   1 #[allow(dead_code)] // Depending on the compilation flags some variants are never used
   2 #[derive(Debug, PartialEq, Eq)]
   3 pub(crate) enum LockHeldState {
   4         HeldByThread,
   5         NotHeldByThread,
   6         #[cfg(any(feature = "_bench_unstable", not(test)))]
   7         Unsupported,
   8 }
   9
  10 pub(crate) trait LockTestExt<'a> {
  11         fn held_by_thread(&self) -> LockHeldState;
  12         type ExclLock;
  13         /// If two instances of the same mutex are being taken at the same time, it's very easy to have
  14         /// a lockorder inversion and risk deadlock. Thus, we default to disabling such locks.
  15         ///
  16         /// However, sometimes they cannot be avoided. In such cases, this method exists to take a
  17         /// mutex while avoiding a test failure. It is deliberately verbose and includes the term
  18         /// "unsafe" to indicate that special care needs to be taken to ensure no deadlocks are
  19         /// possible.
  20         fn unsafe_well_ordered_double_lock_self(&'a self) -> Self::ExclLock;
  21 }
  22
  23 #[cfg(all(feature = "std", not(feature = "_bench_unstable"), test))]
  24 mod debug_sync;
  25 #[cfg(all(feature = "std", not(feature = "_bench_unstable"), test))]
  26 pub use debug_sync::*;
  27 #[cfg(all(feature = "std", not(feature = "_bench_unstable"), test))]
  28 // Note that to make debug_sync's regex work this must not contain `debug_string` in the module name
  29 mod test_lockorder_checks;
  30
  31 #[cfg(all(feature = "std", any(feature = "_bench_unstable", not(test))))]
  32 pub(crate) mod fairrwlock;
  33 #[cfg(all(feature = "std", any(feature = "_bench_unstable", not(test))))]
  34 pub use {std::sync::{Arc, Mutex, Condvar, MutexGuard, RwLock, RwLockReadGuard, RwLockWriteGuard}, fairrwlock::FairRwLock};
  35
  36 #[cfg(all(feature = "std", any(feature = "_bench_unstable", not(test))))]
  37 mod ext_impl {
  38         use super::*;
  39         impl<'a, T: 'a> LockTestExt<'a> for Mutex<T> {
  40                 #[inline]
  41                 fn held_by_thread(&self) -> LockHeldState { LockHeldState::Unsupported }
  42                 type ExclLock = MutexGuard<'a, T>;
  43                 #[inline]
  44                 fn unsafe_well_ordered_double_lock_self(&'a self) -> MutexGuard<T> { self.lock().unwrap() }
  45         }
  46         impl<'a, T: 'a> LockTestExt<'a> for RwLock<T> {
  47                 #[inline]
  48                 fn held_by_thread(&self) -> LockHeldState { LockHeldState::Unsupported }
  49                 type ExclLock = RwLockWriteGuard<'a, T>;
  50                 #[inline]
  51                 fn unsafe_well_ordered_double_lock_self(&'a self) -> RwLockWriteGuard<T> { self.write().unwrap() }
  52         }
  53 }
  54
  55 #[cfg(not(feature = "std"))]
  56 mod nostd_sync;
  57 #[cfg(not(feature = "std"))]
  58 pub use nostd_sync::*;