tracing_appender/
sync.rs

1//! Abstracts over sync primitive implementations.
2//!
3//! Optionally, we allow the Rust standard library's `RwLock` to be replaced
4//! with the `parking_lot` crate's implementation. This may provide improved
5//! performance in some cases. However, the `parking_lot` dependency is an
6//! opt-in feature flag. Because `parking_lot::RwLock` has a slightly different
7//! API than `std::sync::RwLock` (it does not support poisoning on panics), we
8//! wrap the `std::sync` version to ignore poisoning.
9
10#[allow(unused_imports)] // may be used later;
11#[cfg(feature = "parking_lot")]
12pub(crate) use parking_lot::{RwLock, RwLockReadGuard, RwLockWriteGuard};
13
14#[cfg(not(feature = "parking_lot"))]
15pub(crate) use self::std_impl::*;
16
17#[cfg(not(feature = "parking_lot"))]
18mod std_impl {
19    use std::sync::{self, PoisonError, TryLockError};
20    pub(crate) use std::sync::{RwLockReadGuard, RwLockWriteGuard};
21
22    #[derive(Debug)]
23    pub(crate) struct RwLock<T> {
24        inner: sync::RwLock<T>,
25    }
26
27    impl<T> RwLock<T> {
28        pub(crate) fn new(val: T) -> Self {
29            Self {
30                inner: sync::RwLock::new(val),
31            }
32        }
33
34        #[inline]
35        pub(crate) fn get_mut(&mut self) -> &mut T {
36            self.inner.get_mut().unwrap_or_else(PoisonError::into_inner)
37        }
38
39        #[inline]
40        pub(crate) fn read(&self) -> RwLockReadGuard<'_, T> {
41            self.inner.read().unwrap_or_else(PoisonError::into_inner)
42        }
43
44        #[inline]
45        #[allow(dead_code)] // may be used later;
46        pub(crate) fn try_read(&self) -> Option<RwLockReadGuard<'_, T>> {
47            match self.inner.try_read() {
48                Ok(guard) => Some(guard),
49                Err(TryLockError::Poisoned(e)) => Some(e.into_inner()),
50                Err(TryLockError::WouldBlock) => None,
51            }
52        }
53
54        #[inline]
55        pub(crate) fn write(&self) -> RwLockWriteGuard<'_, T> {
56            self.inner.write().unwrap_or_else(PoisonError::into_inner)
57        }
58
59        #[inline]
60        #[allow(dead_code)] // may be used later;
61        pub(crate) fn try_write(&self) -> Option<RwLockWriteGuard<'_, T>> {
62            match self.inner.try_write() {
63                Ok(guard) => Some(guard),
64                Err(TryLockError::Poisoned(e)) => Some(e.into_inner()),
65                Err(TryLockError::WouldBlock) => None,
66            }
67        }
68    }
69}
tracing_appender/sync.rs

tracing_appender/
sync.rs
