Add Windows IOCP selector

.github/workflows/test.yaml

@@ -48,5 +48,14 @@ jobs:
       run: sudo apt-get install -y liburing-dev
 
     - name: Run tests
-      timeout-minutes: 10
+      if: matrix.os != 'windows'
+      timeout-minutes: 15
+      run: bundle exec bake test
+
+    - name: Run tests (Windows)
+      if: matrix.os == 'windows'
+      timeout-minutes: 15
+      # Use bash on Windows so the MSYS2/UCRT64 toolchain is on PATH and
+      # shared-library linking against ws2_32 resolves correctly.
+      shell: bash
       run: bundle exec bake test

ext/extconf.rb

@@ -46,6 +46,14 @@
 	$srcs << "io/event/selector/kqueue.c"
 end
 
+if /mingw|mswin/ =~ RUBY_PLATFORM
+	$srcs << "io/event/selector/iocp.c"
+	# Ensure the MinGW import-library path is in the linker search path.
+	mingw_lib = "#{ENV.fetch('MINGW_PREFIX', '/ucrt64')}/lib"
+	$LDFLAGS << " -L#{mingw_lib}" if File.directory?(mingw_lib)
+	have_library("ws2_32", "WSARecv", "winsock2.h")
+end
+
 have_header("sys/wait.h")
 
 have_header("sys/eventfd.h")
@@ -62,7 +70,8 @@
 # Feature detection for blocking operation support
 if have_func("rb_fiber_scheduler_blocking_operation_extract")
 	# Feature detection for pthread support (needed for WorkerPool)
-	if have_header("pthread.h")
+	# The WorkerPool uses POSIX pthread semantics and is not supported on Windows.
+	if have_header("pthread.h") && !(/mingw|mswin/ =~ RUBY_PLATFORM)
 		append_cflags(["-DHAVE_IO_EVENT_WORKER_POOL"])
 		$srcs << "io/event/worker_pool.c"
 		$srcs << "io/event/worker_pool_test.c"

ext/io/event/event.c

@@ -33,4 +33,8 @@ void Init_IO_Event(void)
 	#ifdef IO_EVENT_SELECTOR_KQUEUE
 	Init_IO_Event_Selector_KQueue(IO_Event_Selector);
 	#endif
+
+	#ifdef IO_EVENT_SELECTOR_IOCP
+	Init_IO_Event_Selector_IOCP(IO_Event_Selector);
+	#endif
 }

ext/io/event/event.h

@@ -19,6 +19,10 @@ void Init_IO_Event(void);
 #include "selector/kqueue.h"
 #endif
 
+#ifdef _WIN32
+#include "selector/iocp.h"
+#endif
+
 #ifdef HAVE_IO_EVENT_WORKER_POOL
 #include "worker_pool.h"
 #endif