dk96-os / coroutines Goto Github PK

Currently, the capacity of the Queue is fixed to the value that it was constructed with.

It is possible to remove this capacity and allow a resizable data structure to contain the Deferred results.

The CoroutineScope parameter was a test, but it did not work as expected.

These methods should be reverted to using the suspend modifier, and it should be noted that this is only safe to use in Kotlin, not in Java code.

The AwaitAll method of the CoroutineQueue can be used to wait for the queue to finish all active tasks, and clear them in queue order.

This is usually only recommended if the active tasks don't have a useful deferred return value, but want to allow them to finish. If it does not matter if the tasks finish, the cancel task is available.

Take a moment to consider the potential use cases where awaitAll is preferred over cancel ...

Enhancements

1. Feedback from the method (a return value), such as the number of tasks that were waited on would be beneficial. This allows the number of discarded results to be logged, or compared with an expected value.

2. Limiting the maximum number of tasks that will be waited for (with a method parameter). The Queue structure makes it easy to predict the order of tasks.

Finished Task Counter

The number of tasks that were completed during the awaitAll call can easily be measured and returned.

Await Limit Parameter

The maximum number of tasks to wait for during an awaitAll call can be added to the method declaration.

Await All Example

Suppose there are initially 5 tasks that require completion, waiting in the queue. Suddenly 5 more tasks are added, which have important deferred values that invalidate the inital 5 tasks.

Since the results from the inital 5 are better off being ignored, but need to complete, you use awaitAll.

Before Await Limit Parameter

You have to call awaitAll before adding the new 5 tasks to the Queue. Alternatively, you can call awaitNext 5 times.

After Await Limit Parameter

You know the initial 5 are the only tasks in the Queue, and they are at the front of the Queue.

You can add the 5 new tasks to the Queue at any time, allowing them to start sooner.

You could do additional work at this point, or make the call to awaitAll with a limit of 5.