Mutex<T>

Struct · namespace System · Since 0.04

struct Mutex<T>

A value that several threads share, guarded by a lock.

thread void Count(Mutex<int> counter, int times)
{
    for (var i = 0; i < times; i += 1)
        counter.Update(n => n + 1);     // or: using (var guard = counter.Lock()) guard.Set(guard.Get() + 1);
}

var counter = Mutex<int>.Create(0);

A Mutex<T> is a handle: copies share the same value and lock, and it can be passed to thread functions. The value only goes in and out as a copy that shares no reference count with anything else (strings are copied into new blocks), so T must be a type that can be copied between threads: numbers, bool, char, enums, strings, ReadOnlySlice<T> of them, SharedPtr<T> of thread-safe values, and Optional<T>/Error<T>/structs made of them - not arrays or containers. While a guard (Mutex<T>.Lock) is held, its Get/Set are safe from every thread; Mutex<T>.Get and Mutex<T>.Set lock just for the one call.

Static methods

Name	Description
Create	A new mutex that holds a copy of value.

Create

static Mutex<T> Create(T value)

A new mutex that holds a copy of value.

Methods

Name	Description
Lock	Waits for the lock and returns a guard that holds it; the guard’s Dispose (e.g. through using) releases it.
Get	A copy of the value (locks for the duration of the call).
Update	Replaces the value with change(value), under the lock: counter.Update(n => n + 1).
Set	Replaces the value (locks for the duration of the call).

Lock

MutexGuard<T> Lock()

Waits for the lock and returns a guard that holds it; the guard’s Dispose (e.g. through using) releases it.

Get

T Get()

A copy of the value (locks for the duration of the call).

Update

void Update(Func<T, T> change)

Replaces the value with change(value), under the lock: counter.Update(n => n + 1).

Set

void Set(T value)

Replaces the value (locks for the duration of the call).