task-group

A small crate for managing groups of tokio tasks.

```rust

let (taskgroup, taskmanager): (TaskGroup, TaskManager<_>) = TaskGroup::new();

taskgroup.clone().spawn("a task", async move { taskgroup.spawn("b task", async move { /* all kinds of things */ Ok(()) }).await.expect("spawned b"); Ok(()) }).await.expect("spawned a");

task_manager.await.expect("everyone successful");

```

A TaskGroup is used to spawn a collection of tasks. The collection has two properties: * if any task returns an error or panicks, all tasks are terminated. * if the TaskManager returned by TaskGroup::new is dropped, all tasks are terminated.

A TaskManager is used to manage a collection of tasks. There are two things you can do with it: * TaskManager impls Future, so you can poll or await on it. It will be Ready when all tasks return Ok(()) and the associated TaskGroup is dropped (so no more tasks can be created), or when any task panicks or returns an Err(E). * When a TaskManager is dropped, all tasks it contains are canceled (terminated). So, if you use a combinator like tokio::time::timeout(duration, task_manager).await, all tasks will be terminated if the timeout occurs.

See examples/ and the tests in src/lib.rs for more examples.