Introduce `Fiber::Scheduler#blocking_operation_wait`. (#12016)

Redirect `rb_nogvl` blocking operations to the fiber scheduler if possible
to prevent stalling the event loop.

[Feature #20876]

1 files changed, 10 insertions, 0 deletions

diff --git a/test/fiber/scheduler.rb b/test/fiber/scheduler.rb
index e6a8256232..ac19bba7a2 100644
--- a/test/fiber/scheduler.rb
+++ b/test/fiber/scheduler.rb
@@ -309,6 +309,16 @@ class Scheduler
       Addrinfo.getaddrinfo(hostname, nil).map(&:ip_address).uniq
     end.value
   end
+
+  def blocking_operation_wait(work)
+    thread = Thread.new(&work)
+
+    thread.join
+
+    thread = nil
+  ensure
+    thread&.kill
+  end
 end
 
 # This scheduler class implements `io_read` and `io_write` hooks which require