Add more tests for close cross-thread/fiber

Also, catch exceptions inside thread/fiber so that stderr is clean and
so that we can ensure we've caught the right IOError.

test/io.rb

@@ -95,11 +95,122 @@
 
 			read_task = Async do
 				r.read(5)
+				nil
+			rescue IOError => e
+				e.to_s
 			end
-			
+
 			r.close
-
-			expect{read_task.wait}.to raise_exception(IOError)
+
+			expect(read_task.wait).to be == 'closed stream'
+		end
+
+		it "can interrupt reading fiber when closing from another fiber" do
+			r, w = IO.pipe
+
+			read_task = Async do
+				r.read(5)
+				nil
+			rescue IOError => e
+				e.to_s
+			end
+
+			close_task = Async do
+				r.close
+			end
+
+			close_task.wait
+			expect(read_task.wait).to be == 'closed stream'
+		end
+
+		it "can interrupt reading fiber when closing from a new thread" do
+			r, w = IO.pipe
+
+			read_task = Async do
+				r.read(5)
+				nil
+			rescue IOError => e
+				e.to_s
+			end
+
+			close_thread = Thread.new do
+				r.close
+			end
+
+			close_thread.value
+			expect(read_task.wait).to be == 'closed stream'
+		end
+
+		it "can interrupt reading fiber when closing from a fiber in a new thread" do
+			r, w = IO.pipe
+
+			read_task = Async do
+				r.read(5)
+				nil
+			rescue IOError => e
+				e.to_s
+			end
+
+			close_thread = Thread.new do
+				close_task = Async do
+					r.close
+				end
+				close_task.wait
+			end
+
+			close_thread.value
+			expect(read_task.wait).to be == 'closed stream'
+		end
+
+		it "can interrupt reading thread when closing from a fiber" do
+			r, w = IO.pipe
+
+			read_thread = Thread.new do
+				Thread.current.report_on_exception = false
+				r.read(5)
+				nil
+			rescue IOError => e
+				e.to_s
+			end
+
+			# Wait until read_thread blocks on I/O
+			while read_thread.status != 'sleep'
+				sleep(0.001)
+			end
+
+			close_task = Async do
+				r.close
+			end
+
+			close_task.wait
+			expect(read_thread.value).to be == 'closed stream'
+		end
+
+		it "can interrupt reading fiber in a new thread when closing from a fiber" do
+			r, w = IO.pipe
+
+			read_thread = Thread.new do
+				Thread.current.report_on_exception = false
+				read_task = Async do
+					r.read(5)
+					nil
+				rescue IOError => e
+					e.to_s
+				end
+				read_task.wait
+			end
+
+			# Wait until read_thread blocks on I/O
+			while read_thread.status != 'sleep'
+				sleep(0.001)
+			end
+
+			close_task = Async do
+				r.close
+			end
+			close_task.wait
+
+			expect(read_thread.value).to be == 'closed stream'
 		end
 	end
 end