From 4bf27174249ffe081bbfd78f39d14391c194a76a Mon Sep 17 00:00:00 2001
From: Quinton Miller <nicetas.c@gmail.com>
Date: Tue, 2 May 2023 09:20:57 +0800
Subject: [PATCH] Fix `-Dpreview_mt` infinite loop on Windows

---
 src/crystal/scheduler.cr | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/crystal/scheduler.cr b/src/crystal/scheduler.cr
index 61df03294875..0667626f787e 100644
--- a/src/crystal/scheduler.cr
+++ b/src/crystal/scheduler.cr
@@ -73,7 +73,7 @@ class Crystal::Scheduler
   {% end %}
 
   {% if flag?(:preview_mt) %}
-    @fiber_channel = Crystal::FiberChannel.new
+    private getter(fiber_channel : Crystal::FiberChannel) { Crystal::FiberChannel.new }
     @free_stacks = Deque(Void*).new
   {% end %}
   @lock = Crystal::SpinLock.new
@@ -199,6 +199,7 @@ class Crystal::Scheduler
     end
 
     def run_loop
+      fiber_channel = self.fiber_channel
       loop do
         @lock.lock
         if runnable = @runnables.shift?
@@ -208,7 +209,7 @@ class Crystal::Scheduler
         else
           @sleeping = true
           @lock.unlock
-          fiber = @fiber_channel.receive
+          fiber = fiber_channel.receive
 
           @lock.lock
           @sleeping = false
@@ -222,7 +223,7 @@ class Crystal::Scheduler
     def send_fiber(fiber : Fiber)
       @lock.lock
       if @sleeping
-        @fiber_channel.send(fiber)
+        fiber_channel.send(fiber)
       else
         @runnables << fiber
       end