X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fsync%2Fmod.rs;h=348bd90274ae1632b1cec63cf98e9249d9ac7425;hb=7c9463668a4f71663746e57bdb09ee6b91797d5a;hp=50ef40e295f50d0a0d9095a0f3dfe4c73916a340;hpb=d0b8f455fe86d3e55231d35d35dd96693abe2049;p=rust-lightning

diff --git a/lightning/src/sync/mod.rs b/lightning/src/sync/mod.rs
index 50ef40e2..348bd902 100644
--- a/lightning/src/sync/mod.rs
+++ b/lightning/src/sync/mod.rs
@@ -3,37 +3,52 @@
 pub(crate) enum LockHeldState {
 	HeldByThread,
 	NotHeldByThread,
-	#[cfg(any(feature = "_bench_unstable", not(test)))]
+	#[cfg(any(ldk_bench, not(test)))]
 	Unsupported,
 }
 
-pub(crate) trait LockTestExt {
+pub(crate) trait LockTestExt<'a> {
 	fn held_by_thread(&self) -> LockHeldState;
+	type ExclLock;
+	/// If two instances of the same mutex are being taken at the same time, it's very easy to have
+	/// a lockorder inversion and risk deadlock. Thus, we default to disabling such locks.
+	///
+	/// However, sometimes they cannot be avoided. In such cases, this method exists to take a
+	/// mutex while avoiding a test failure. It is deliberately verbose and includes the term
+	/// "unsafe" to indicate that special care needs to be taken to ensure no deadlocks are
+	/// possible.
+	fn unsafe_well_ordered_double_lock_self(&'a self) -> Self::ExclLock;
 }
 
-#[cfg(all(feature = "std", not(feature = "_bench_unstable"), test))]
+#[cfg(all(feature = "std", not(ldk_bench), test))]
 mod debug_sync;
-#[cfg(all(feature = "std", not(feature = "_bench_unstable"), test))]
+#[cfg(all(feature = "std", not(ldk_bench), test))]
 pub use debug_sync::*;
-#[cfg(all(feature = "std", not(feature = "_bench_unstable"), test))]
+#[cfg(all(feature = "std", not(ldk_bench), test))]
 // Note that to make debug_sync's regex work this must not contain `debug_string` in the module name
 mod test_lockorder_checks;
 
-#[cfg(all(feature = "std", any(feature = "_bench_unstable", not(test))))]
+#[cfg(all(feature = "std", any(ldk_bench, not(test))))]
 pub(crate) mod fairrwlock;
-#[cfg(all(feature = "std", any(feature = "_bench_unstable", not(test))))]
+#[cfg(all(feature = "std", any(ldk_bench, not(test))))]
 pub use {std::sync::{Arc, Mutex, Condvar, MutexGuard, RwLock, RwLockReadGuard, RwLockWriteGuard}, fairrwlock::FairRwLock};
 
-#[cfg(all(feature = "std", any(feature = "_bench_unstable", not(test))))]
+#[cfg(all(feature = "std", any(ldk_bench, not(test))))]
 mod ext_impl {
 	use super::*;
-	impl<T> LockTestExt for Mutex<T> {
+	impl<'a, T: 'a> LockTestExt<'a> for Mutex<T> {
 		#[inline]
 		fn held_by_thread(&self) -> LockHeldState { LockHeldState::Unsupported }
+		type ExclLock = MutexGuard<'a, T>;
+		#[inline]
+		fn unsafe_well_ordered_double_lock_self(&'a self) -> MutexGuard<T> { self.lock().unwrap() }
 	}
-	impl<T> LockTestExt for RwLock<T> {
+	impl<'a, T: 'a> LockTestExt<'a> for RwLock<T> {
 		#[inline]
 		fn held_by_thread(&self) -> LockHeldState { LockHeldState::Unsupported }
+		type ExclLock = RwLockWriteGuard<'a, T>;
+		#[inline]
+		fn unsafe_well_ordered_double_lock_self(&'a self) -> RwLockWriteGuard<T> { self.write().unwrap() }
 	}
 }