1 files changed, 44 insertions(+), 19 deletions(-)

M lib/em_fiberscheduler.rb

@@ 87,25 87,7 @@ module EventMachine
 		def process_wait(pid, flags)
 			fiber = Fiber.current
 			EM.schedule do
-				conn = EM.watch_process(pid, WatchProcess)
-				conn.fiber = fiber
-			rescue Unsupported
-				fiber do
-					# Inspired by bruno-/fiber_scheduler
-					reader, writer = IO.pipe
-					thread = Thread.new do
-						Process::Status.wait(pid, flags)
-					ensure
-						writer.close
-					end
-
-					io_wait(reader, IO::READABLE)
-					fiber.resume(thread.value)
-				ensure
-					reader.close
-					writer.close
-					thread&.kill
-				end
+				ProcessWait.for(fiber, pid, flags).call
 			end
 			Fiber.yield
 		end


@@ 133,6 115,49 @@ module EventMachine
 			Fiber.yield
 		end
 
+		class ProcessWait
+			def self.for(fiber, pid, flags)
+				# The only way to check this is to just try it
+				conn = EM.watch_process(pid, WatchProcess)
+				conn.fiber = fiber
+				new
+			rescue Unsupported
+				Fallback.new(fiber, pid, flags)
+			end
+
+			def call; end
+
+			# Inspired by bruno-/fiber_scheduler
+			class Fallback
+				def initialize(fiber, pid, flags)
+					@fiber = fiber
+					@pid = pid
+					@flags = flags
+					@reader, @writer = IO.pipe
+				end
+
+				def thread
+					@thread ||= Thread.new do
+						Process::Status.wait(@pid, @flags)
+					ensure
+						@writer.close
+					end
+				end
+
+				def call
+					thread
+					Fiber.schedule do
+						Fiber.scheduler&.io_wait(@reader, IO::READABLE)
+						@fiber.resume(thread.value)
+					ensure
+						@reader.close
+						@writer.close
+						@thread&.kill
+					end
+				end
+			end
+		end
+
 		module WatchProcess
 			attr_writer :fiber