From 0157026816cc1d3f4592b444eb97ed8c3e0763a5 Mon Sep 17 00:00:00 2001
From: Fletcher Dares <fletcher.dares@shopify.com>
Date: Mon, 11 May 2026 18:21:15 -0400
Subject: [PATCH 1/2] Keep blocked scheduler fibers alive during GC

---
 fixtures/io/event/test_scheduler.rb |  3 +++
 test/io/event/worker_pool.rb        | 30 ++++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/fixtures/io/event/test_scheduler.rb b/fixtures/io/event/test_scheduler.rb
index 202105de..7faed994 100644
--- a/fixtures/io/event/test_scheduler.rb
+++ b/fixtures/io/event/test_scheduler.rb
@@ -41,6 +41,7 @@ def initialize(selector: nil, worker_pool: nil, maximum_worker_count: nil)
 			
 			# Track the number of fibers that are blocked.
 			@blocked = 0
+			@blocking = {}
 		end
 		
 		# @attribute [WorkerPool] The worker pool used for executing blocking operations.
@@ -80,8 +81,10 @@ def block(blocker, timeout = nil)
 			
 			begin
 				@blocked += 1
+				@blocking[fiber] = true
 				@selector.transfer
 			ensure
+				@blocking.delete(fiber)
 				@blocked -= 1
 			end
 		ensure
diff --git a/test/io/event/worker_pool.rb b/test/io/event/worker_pool.rb
index c21126da..4f31978f 100644
--- a/test/io/event/worker_pool.rb
+++ b/test/io/event/worker_pool.rb
@@ -122,7 +122,35 @@
 			expect(result[:result]).to be == :completed
 			expect(result[:duration]).to be == 0.05
 		end
-		
+
+		it "keeps blocked fibers alive during garbage collection" do
+			result = nil
+
+			Thread.new do
+				Fiber.set_scheduler(scheduler)
+
+				gc_thread = Thread.new do
+					sleep(0.02)
+					GC.start(full_mark: true, immediate_sweep: true)
+				end
+
+				Fiber.schedule do
+					result = IO::Event::WorkerPool.busy(duration: 0.1)
+				end
+
+				scheduler.run
+				gc_thread.value
+			ensure
+				Fiber.set_scheduler(nil)
+				scheduler.close
+			end.value
+
+			expect(result).to have_keys(
+				cancelled: be == false,
+				result: be == :completed
+			)
+		end
+
 		it "can cancel a busy operation using unblock function" do
 			# This tests the cancellation mechanism through rb_thread_call_without_gvl
 			completed = false

From c14c09b671f21acade9bef5ebdc2bfd626b47646 Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@oriontransfer.co.nz>
Date: Tue, 12 May 2026 09:05:56 +0900
Subject: [PATCH 2/2] RuboCop.

---
 test/io/event/worker_pool.rb | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/test/io/event/worker_pool.rb b/test/io/event/worker_pool.rb
index 4f31978f..a0bf1eda 100644
--- a/test/io/event/worker_pool.rb
+++ b/test/io/event/worker_pool.rb
@@ -122,35 +122,35 @@
 			expect(result[:result]).to be == :completed
 			expect(result[:duration]).to be == 0.05
 		end
-
+		
 		it "keeps blocked fibers alive during garbage collection" do
 			result = nil
-
+			
 			Thread.new do
 				Fiber.set_scheduler(scheduler)
-
+				
 				gc_thread = Thread.new do
 					sleep(0.02)
 					GC.start(full_mark: true, immediate_sweep: true)
 				end
-
+				
 				Fiber.schedule do
 					result = IO::Event::WorkerPool.busy(duration: 0.1)
 				end
-
+				
 				scheduler.run
 				gc_thread.value
 			ensure
 				Fiber.set_scheduler(nil)
 				scheduler.close
 			end.value
-
+			
 			expect(result).to have_keys(
 				cancelled: be == false,
 				result: be == :completed
 			)
 		end
-
+		
 		it "can cancel a busy operation using unblock function" do
 			# This tests the cancellation mechanism through rb_thread_call_without_gvl
 			completed = false