extra_waiters

This library provides synchronization primitives built on top of parking_lot_core. The various waiters here are a mix between a Condvar and a Mutex, with the specific details being particular to each waiter.

Note that the use of this library does not require a Mutex.

Examples of usage can be seen in the test cases written for each module, however the general pattern for each of the waiters is as follows:

AttentiveWaiter

This waiter provides functions to do the following:

• Not wait for a notification, should one have occurred before the last time a notification was polled for.

• Execute some code before the thread sleeps in a way that no thread could notify between the time the user code runs and the thread sleeps.

• Perform the previous two bullet points using timeout functions which timeout at a certain Instant in time, or after a certain Duration.

OnceWaiter

This waiter provides functions to do the following:

• Ensure that an initialization function is only run once.

• Ensure that an initialization function is only run on one thread at a time.

• Run another thread's initialization function in case the currently running one panics.

• Wait until the waiter is initialized without providing an initialization function.

• Perform the previous bullet points using timeout functions which timeout at a certain Instant in time, or after a certain Duration.

Spinlock

A simple spinlock built on atomic primitives.

This is not recommended to be used in most instances, however can be useful in certain cases.