crystal-wait-group

This is a Crystal implementation of golang's sync.WaitGroup

There's probably still some work that needs to be done here, but it seems to work pretty well!

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     crystal-wait-group:
       github: jasonrobot/crystal-wait-group
   

2. Run shards install

Usage

require "crystal-wait-group"

To use like Go's WaitGroup, there are the add, done, and wait methods. They should work just as expected.

wg = WaitGroup.new
wg.add
spawn do
  sleep 1
  wg.done
end
wg.wait

As a fun crystal-style addition, there is also a spawn method which takes a block and spawns it in a fiber that is waited for by the WaitGroup.

wg = WaitGroup.new
wg.spawn do
  sleep 1
end
wg.wait

Development

All feedback is welcome! This is my first time playing with concurrency at this level, or doing low-level Crystal stuff, so there's gotta be room for improvment. The usage of Intrinsics.pause is taken from Crystal::SpinLock. Basically what I've gone for here is a version of SpinLock built around an atomic counter.

Contributing

1. Fork it (https://github.com/jasonrobot/crystal-wait-group/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Jason Howell - creator and maintainer