Log message:
devel/ruby-async: update to 2.21.1

2.19.0 (2024-11-08)

Async::Scheduler Debugging

Occasionally on issues, I encounter people asking for help and I need more
information.  Pressing Ctrl-C to exit a hung program is common, but it
usually doesn't provide enough information to diagnose the problem.  Setting
the CONSOLE_LEVEL=debug environment variable will now print additional
information about the scheduler when you interrupt it, including a backtrace
of the current tasks.

> CONSOLE_LEVEL=debug bundle exec ruby ./test.rb
^C  0.0s    debug: Async::Reactor [oid=0x974] [ec=0x988] [pid=9116] [2024-11-08 \ 
14:12:03 +1300]
               | Scheduler interrupted: Interrupt
               | #<Async::Reactor:0x0000000000000974 1 children (running)>
               | 	#<Async::Task:0x000000000000099c \ 
/Users/samuel/Developer/socketry/async/lib/async/scheduler.rb:185:in `transfer' \ 
(running)>
               | 	→ \ 
/Users/samuel/Developer/socketry/async/lib/async/scheduler.rb:185:in `transfer'
               | 	  \ 
/Users/samuel/Developer/socketry/async/lib/async/scheduler.rb:185:in `block'
               | 	  \ 
/Users/samuel/Developer/socketry/async/lib/async/scheduler.rb:207:in \ 
`kernel_sleep'
               | 	  /Users/samuel/Developer/socketry/async/test.rb:7:in `sleep'
               | 	  /Users/samuel/Developer/socketry/async/test.rb:7:in `sleepy'
               | 	  /Users/samuel/Developer/socketry/async/test.rb:12:in `block \ 
in <top (required)>'
               | 	  \ 
/Users/samuel/Developer/socketry/async/lib/async/task.rb:197:in `block in run'
               | 	  \ 
/Users/samuel/Developer/socketry/async/lib/async/task.rb:420:in `block in \ 
schedule'
/Users/samuel/Developer/socketry/async/lib/async/scheduler.rb:317:in `select': \ 
Interrupt
... (backtrace continues) ...

This gives better visibility into what the scheduler is doing, and should
help diagnose issues.

Console Shims

The async gem depends on console gem, because my goal was to have good
logging by default without thinking about it too much.  However, some users
prefer to avoid using the console gem for logging, so I've added an
experimental set of shims which should allow you to bypass the console gem
entirely.

require 'async/console'
require 'async'

Async{raise "Boom"}

Will now use Kernel#warn to print the task failure warning:

#<Async::Task:0x00000000000012d4 \ 
/home/samuel/Developer/socketry/async/lib/async/task.rb:104:in `backtrace' \ 
(running)>
Task may have ended with unhandled exception.
(irb):4:in `block in <top (required)>': Boom (RuntimeError)
	from /home/samuel/Developer/socketry/async/lib/async/task.rb:197:in `block in run'
	from /home/samuel/Developer/socketry/async/lib/async/task.rb:420:in `block in \ 
schedule'

2.20.0 (2024-11-10)

Traces and Metrics Providers

Async now has traces and metrics providers for various core classes.  This
allows you to emit traces and metrics to a suitable backend (including
DataDog, New Relic, OpenTelemetry, etc.) for monitoring and debugging
purposes.

To take advantage of this feature, you will need to introduce your own
config/traces.rb and config/metrics.rb.  Async's own repository includes
these files for testing purposes, you could copy them into your own project
and modify them as needed.

2.21.0 (2024-11-21)

(No release note, not released?)

2.21.1 (2024-11-27)

Worker Pool

Ruby 3.4 will feature a new fiber scheduler hook, blocking_operation_wait
which allows the scheduler to redirect the work given to rb_nogvl to a
worker pool.

The Async scheduler optionally supports this feature using a worker pool, by \ 
using the following environment variable:

ASYNC_SCHEDULER_DEFAULT_WORKER_POOL=true

This will cause the scheduler to use a worker pool for general blocking
operations, rather than blocking the event loop.

It should be noted that this isn't a net win, as the overhead of using a
worker pool can be significant compared to the rb_nogvl work.  As such, it
is recommended to benchmark your application with and without the worker
pool to determine if it is beneficial.

Log message:
devel/ruby-async: update to 2.18.0

2.18.0 (2024-10-29)

* Add support for Sync(annotation:), so that you can annotate the block with
  a description of what it does, even if it doesn't create a new task.

Log message:
devel/ruby-async: update to 2.17.0

2.15.0 (2024-08-04)

* Allow transient tasks to exit completely. (#336)

2.15.1 (2024-08-07)

* Allow transient tasks to exit gracefully. (#337)

2.15.2 (2024-08-07)

* Transient tasks should only be stopped once. (#338)

2.15.3 (2024-08-08)

* Ensure that defer_stop resets state. (#339)

2.16.0 (2024-08-23)

Better Handling of Async and Sync in Nested Fibers

Interleaving bare fibers within Async and Sync blocks should not cause
problems, but it presents a number of issues in the current implementation.
Tracking the parent-child relationship between tasks, when they are
interleaved with bare fibers, is difficult.  The current implementation
assumes that if there is no parent task, then it should create a new
reactor.  This is not always the case, as the parent task might not be
visible due to nested Fibers.  As a result, Async will create a new reactor,
trying to stop the existing one, causing major internal consistency issues.

I encountered this issue when trying to use Async within a streaming
response in Rails.  The protocol-rack uses a normal fiber to wrap streaming
responses, and if you try to use Async within it, it will create a new
reactor, causing the server to lock up.

Ideally, Async and Sync helpers should work when any Fiber.scheduler is
defined.  Right now, it's unrealistic to expect Async::Task to work in any
scheduler, but at the very least, the following should work:

    reactor = Async::Reactor.new # internally calls Fiber.set_scheduler

    # This should run in the above reactor, rather than creating a new one.
    Async do
      puts "Hello World"
    end

In order to do this, bare Async and Sync blocks should use Fiber.scheduler
as a parent if possible.

See #340 for more details.

2.16.1 (2024-08-26)

* Add timeout to timeout error message.

2.17.0 (2024-09-05)

* Introduce Async::Queue#push and Async::Queue#pop for compatibility with
  ::Queue.

Log message:
xdevel/ruby-async: update to 2.14.2

2.14.1 (2024-07-15)

* Minor updates to compatibility guide.
* Add initial debugging guide.
* Restore error logging. (#331)
* Remove unused gem dependency.
* Use direct instance variable for async_task.

2.14.2 (2024-07-17)

* Fix failure logs and add explicit tests.

Log message:
devel/ruby-async: update to 2.14.1

2.14.1 (2024-07-15)

* Minor updates to compatibility guide.
* Add initial debugging guide.
* Restore error logging. (#331)
* Use direct instance variable for async_task.

Log message:
devel/ruby-async: update to 2.14.0

2.14.0 (2024-07-14)

* Opt-in to task failures using $DEBUG only.
* Update external tests - drop async-io.

Log message:
devel/ruby-async: update to 2.13.0

2.13.0 (2024-07-12)

* Update logo.
* Waiter#async: pass options to parent (#327)
* Minor documentation updates.
* Allow queue to be used for task finished. (#276)

Log message:
devel/ruby-async: update to 2.12.1

2.12.1 (2024-06-23)

* Docs: correct ruby version requirement
* Docs: various typo fixes
* Fix idle load computation. (#323)
* Propagate interrupts when exiting event loop. (#322)