From 324a7d5e2fef3c2304af6883100fcad2c503d0ef Mon Sep 17 00:00:00 2001
From: Koichi Sasada <ko1@atdot.net>
Date: Tue, 27 May 2025 03:58:04 +0900
Subject: [PATCH 1/2] `Ractor::Port`

* Added `Ractor::Port`
  * `Ractor::Port#receive` (support multi-threads)
  * `Rcator::Port#close`
  * `Ractor::Port#closed?`
* Added some methods
  * `Ractor#join`
  * `Ractor#value`
  * `Ractor#monitor`
  * `Ractor#unmonitor`
* Removed some methods
  * `Ractor#take`
  * `Ractor.yield`
* Change the spec
  * `Racotr.select`

You can wait for multiple sequences of messages with `Ractor::Port`.

```ruby
ports = 3.times.map{ Ractor::Port.new }
ports.map.with_index do |port, ri|
  Ractor.new port,ri do |port, ri|
    3.times{|i| port << "r#{ri}-#{i}"}
  end
end

p ports.each{|port| pp 3.times.map{port.receive}}

```

In this example, we use 3 ports, and 3 Ractors send messages to them respectively.
We can receive a series of messages from each port.

You can use `Ractor#value` to get the last value of a Ractor's block:

```ruby
result = Ractor.new do
  heavy_task()
end.value
```

You can wait for the termination of a Ractor with `Ractor#join` like this:

```ruby
Ractor.new do
  some_task()
end.join
```

`#value` and `#join` are similar to `Thread#value` and `Thread#join`.

To implement `#join`, `Ractor#monitor` (and `Ractor#unmonitor`) is introduced.

This commit changes `Ractor.select()` method.
It now only accepts ports or Ractors, and returns when a port receives a message or a Ractor terminates.

We removes `Ractor.yield` and `Ractor#take` because:
* `Ractor::Port` supports most of similar use cases in a simpler manner.
* Removing them significantly simplifies the code.

We also change the internal thread scheduler code (thread_pthread.c):
* During barrier synchronization, we keep the `ractor_sched` lock to avoid deadlocks.
  This lock is released by `rb_ractor_sched_barrier_end()`
  which is called at the end of operations that require the barrier.
* fix potential deadlock issues by checking interrupts just before setting UBF.

https://bugs.ruby-lang.org/issues/21262
---
 test/uri/test_common.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/uri/test_common.rb b/test/uri/test_common.rb
index 6326aec..fef785a 100644
--- a/test/uri/test_common.rb
+++ b/test/uri/test_common.rb
@@ -75,7 +75,7 @@ def test_ractor
     return unless defined?(Ractor)
     assert_ractor(<<~RUBY, require: 'uri')
       r = Ractor.new { URI.parse("https://ruby-lang.org/").inspect }
-      assert_equal(URI.parse("https://ruby-lang.org/").inspect, r.take)
+      assert_equal(URI.parse("https://ruby-lang.org/").inspect, r.value)
     RUBY
   end
 

From 443ed0cf8540588b3e4e9bf8b52cb8834f13c8bc Mon Sep 17 00:00:00 2001
From: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date: Tue, 3 Jun 2025 16:55:28 +0900
Subject: [PATCH 2/2] Alias value or join to take in old Ruby

---
 test/uri/test_common.rb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/uri/test_common.rb b/test/uri/test_common.rb
index fef785a..fef3f70 100644
--- a/test/uri/test_common.rb
+++ b/test/uri/test_common.rb
@@ -74,6 +74,9 @@ def test_extract
   def test_ractor
     return unless defined?(Ractor)
     assert_ractor(<<~RUBY, require: 'uri')
+      class Ractor
+        alias value take unless method_defined? :value # compat with Ruby 3.4 and olders
+      end
       r = Ractor.new { URI.parse("https://ruby-lang.org/").inspect }
       assert_equal(URI.parse("https://ruby-lang.org/").inspect, r.value)
     RUBY