Crate raii_counter

Rust type for a RAII Counter (counts number of held instances, decrements count on Drop), implemented with Arc<AtomicUsize>.

Useful for tracking the number of holders exist for a handle, tracking the number of transactions that are in-flight, etc.

Additional Features

• Counters can have a size, eg. a Counter with size 4 adds 4 to the count, and removes 4 when dropped.
• NotifyHandles can be used for efficient conditional checking, eg. if you want to wait until there are no in-flight transactions, see: CounterBuilder::create_notify / WeakCounterBuilder::create_notify and NotifyHandle::wait_until_condition.

Demo

extern crate raii_counter;
use raii_counter::Counter;

let counter = Counter::builder().build();
assert_eq!(counter.count(), 1);

let weak = counter.downgrade();
assert_eq!(weak.count(), 0);

{
    let _counter1 = weak.spawn_upgrade();
    assert_eq!(weak.count(), 1);
    let _counter2 = weak.spawn_upgrade();
    assert_eq!(weak.count(), 2);
}

assert_eq!(weak.count(), 0);

Structs

• Counter
  Essentially an AtomicUsize that is clonable and whose count is based on the number of copies (and their size). The count is automatically updated on Drop.
• CounterBuilder
  A builder for the Counter.
• NotifyHandle
  Struct that enables functionality like waiting to be notified when the count of a crate::Counter or crate::WeakCounter changes.
• WeakCounter
  A ‘weak’ Counter that does not affect the count.
• WeakCounterBuilder
  A builder for the WeakCounter.

Enums

• NotifyError
• NotifyTimeoutError