From a621bfb12268dc71cc4b756bd746a27c544bd181 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/test_tmpdir.rb | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/test/test_tmpdir.rb b/test/test_tmpdir.rb
index adc2918..789f433 100644
--- a/test/test_tmpdir.rb
+++ b/test/test_tmpdir.rb
@@ -134,16 +134,17 @@ def assert_mktmpdir_traversal
 
   def test_ractor
     assert_ractor(<<~'end;', require: "tmpdir")
-      r = Ractor.new do
+      port = Ractor::Port.new
+      r = Ractor.new port do |port|
         Dir.mktmpdir() do |d|
-          Ractor.yield d
+          port << d
           Ractor.receive
         end
       end
-      dir = r.take
+      dir = port.receive
       assert_file.directory? dir
       r.send true
-      r.take
+      r.join
       assert_file.not_exist? dir
     end;
   end

From f12c766996eb55651a94de617f8814e0640b877b Mon Sep 17 00:00:00 2001
From: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date: Tue, 3 Jun 2025 16:49:10 +0900
Subject: [PATCH 2/2] Restore Ractor.yield style test for old version of Ruby

---
 test/test_tmpdir.rb | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/test/test_tmpdir.rb b/test/test_tmpdir.rb
index 789f433..c91fc33 100644
--- a/test/test_tmpdir.rb
+++ b/test/test_tmpdir.rb
@@ -134,18 +134,32 @@ def assert_mktmpdir_traversal
 
   def test_ractor
     assert_ractor(<<~'end;', require: "tmpdir")
-      port = Ractor::Port.new
-      r = Ractor.new port do |port|
-        Dir.mktmpdir() do |d|
-          port << d
-          Ractor.receive
+      if defined?(Ractor::Port)
+        port = Ractor::Port.new
+        r = Ractor.new port do |port|
+          Dir.mktmpdir() do |d|
+            port << d
+            Ractor.receive
+          end
+        end
+        dir = port.receive
+        assert_file.directory? dir
+        r.send true
+        r.join
+        assert_file.not_exist? dir
+      else
+        r = Ractor.new do
+          Dir.mktmpdir() do |d|
+            Ractor.yield d
+            Ractor.receive
+          end
         end
+        dir = r.take
+        assert_file.directory? dir
+        r.send true
+        r.take
+        assert_file.not_exist? dir
       end
-      dir = port.receive
-      assert_file.directory? dir
-      r.send true
-      r.join
-      assert_file.not_exist? dir
     end;
   end
 end