1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126

//! Helper module that wraps some Mutex types with different implementations.

// ----------------------------------------------------------------------------

#[cfg(feature = "multi_threaded")]
pub use parking_lot::MutexGuard;

#[cfg(feature = "multi_threaded")]
#[derive(Default)]
pub struct Mutex<T>(parking_lot::Mutex<T>);

#[cfg(feature = "multi_threaded")]
impl<T> Mutex<T> {
    #[inline(always)]
    pub fn new(val: T) -> Self {
        Self(parking_lot::Mutex::new(val))
    }

    #[cfg(debug_assertions)]
    pub fn lock(&self) -> MutexGuard<'_, T> {
        // TODO: detect if we are trying to lock the same mutex from the same thread (bad)
        // vs locking it from another thread (fine).
        // At the moment we just panic on any double-locking of a mutex (so no multithreaded support in debug builds)
        self.0
            .try_lock()
            .expect("The Mutex is already locked. Probably a bug")
    }

    #[inline(always)]
    #[cfg(not(debug_assertions))]
    pub fn lock(&self) -> MutexGuard<'_, T> {
        self.0.lock()
    }
}

// ---------------------

#[cfg(feature = "multi_threaded")]
pub use parking_lot::{RwLockReadGuard, RwLockWriteGuard};

#[cfg(feature = "multi_threaded")]
#[derive(Default)]
pub struct RwLock<T>(parking_lot::RwLock<T>);

#[cfg(feature = "multi_threaded")]
impl<T> RwLock<T> {
    #[inline(always)]
    pub fn new(val: T) -> Self {
        Self(parking_lot::RwLock::new(val))
    }

    #[inline(always)]
    pub fn read(&self) -> RwLockReadGuard<'_, T> {
        self.0.read()
    }

    #[inline(always)]
    pub fn write(&self) -> RwLockWriteGuard<'_, T> {
        self.0.write()
    }
}

// ----------------------------------------------------------------------------
// `atomic_refcell` will panic if multiple threads try to access the same value

#[cfg(not(feature = "multi_threaded"))]
pub use atomic_refcell::AtomicRefMut as MutexGuard;

#[cfg(not(feature = "multi_threaded"))]
#[derive(Default)]
pub struct Mutex<T>(atomic_refcell::AtomicRefCell<T>);

#[cfg(not(feature = "multi_threaded"))]
impl<T> Mutex<T> {
    #[inline(always)]
    pub fn new(val: T) -> Self {
        Self(atomic_refcell::AtomicRefCell::new(val))
    }

    /// Panics if already locked.
    #[inline(always)]
    pub fn lock(&self) -> MutexGuard<'_, T> {
        self.0.borrow_mut()
    }
}

// ---------------------

#[cfg(not(feature = "multi_threaded"))]
pub use {
    atomic_refcell::AtomicRef as RwLockReadGuard, atomic_refcell::AtomicRefMut as RwLockWriteGuard,
};

#[cfg(not(feature = "multi_threaded"))]
#[derive(Default)]
pub struct RwLock<T>(atomic_refcell::AtomicRefCell<T>);

#[cfg(not(feature = "multi_threaded"))]
impl<T> RwLock<T> {
    #[inline(always)]
    pub fn new(val: T) -> Self {
        Self(atomic_refcell::AtomicRefCell::new(val))
    }

    #[inline(always)]
    pub fn read(&self) -> RwLockReadGuard<'_, T> {
        self.0.borrow()
    }

    /// Panics if already locked.
    #[inline(always)]
    pub fn write(&self) -> RwLockWriteGuard<'_, T> {
        self.0.borrow_mut()
    }
}

// ----------------------------------------------------------------------------

impl<T> Clone for Mutex<T>
where
    T: Clone,
{
    fn clone(&self) -> Self {
        Self::new(self.lock().clone())
    }
}