1 files changed, 122 insertions, 0 deletions
diff --git a/v_windows/v/vlib/sync/channel_select_3_test.v b/v_windows/v/vlib/sync/channel_select_3_test.v
new file mode 100644
index 0000000..fdf6096
--- /dev/null
+++ b/v_windows/v/vlib/sync/channel_select_3_test.v
@@ -0,0 +1,122 @@
+import time
+import sync
+
+struct St {
+	a int
+}
+
+fn getint() int {
+	return 8
+}
+
+fn f1(ch1 chan int, ch2 chan St, ch3 chan int, ch4 chan int, ch5 chan int, mut sem sync.Semaphore) {
+	mut a := 5
+	select {
+		a = <-ch3 {
+			a = 0
+		}
+		b := <-ch2 {
+			a = b.a
+		}
+		ch3 <- 5 {
+			a = 1
+		}
+		ch2 <- St{
+			a: 37
+		} {
+			a = 2
+		}
+		ch4 <- (6 + 7 * 9) {
+			a = 8
+		}
+		ch5 <- getint() {
+			a = 9
+		}
+		300 * time.millisecond {
+			a = 3
+		}
+	}
+	assert a == 3
+	sem.post()
+}
+
+fn f2(ch1 chan St, ch2 chan int, mut sem sync.Semaphore) {
+	mut r := 23
+	for i in 0 .. 2 {
+		select {
+			b := <-ch1 {
+				r = b.a
+			}
+			ch2 <- r {
+				r = 17
+			}
+		}
+		if i == 0 {
+			assert r == 17
+		} else {
+			assert r == 13
+		}
+	}
+	sem.post()
+}
+
+fn test_select_blocks() {
+	ch1 := chan int{cap: 1}
+	ch2 := chan St{}
+	ch3 := chan int{}
+	ch4 := chan int{}
+	ch5 := chan int{}
+	mut sem := sync.new_semaphore()
+	mut r := false
+	t := select {
+		b := <-ch1 {
+			println(b)
+		}
+		else {
+			// no channel ready
+			r = true
+		}
+	}
+	assert r == true
+	assert t == true
+	go f2(ch2, ch3, mut sem)
+	n := <-ch3
+	assert n == 23
+	ch2 <- St{
+		a: 13
+	}
+	sem.wait()
+	stopwatch := time.new_stopwatch()
+	go f1(ch1, ch2, ch3, ch4, ch5, mut sem)
+	sem.wait()
+	elapsed_ms := f64(stopwatch.elapsed()) / time.millisecond
+	// https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/high-resolution-timers
+	// > For example, for Windows running on an x86 processor, the default interval between
+	// > system clock ticks is typically about 15 milliseconds, and the minimum interval
+	// > between system clock ticks is about 1 millisecond.
+	assert elapsed_ms >= 280.0 // 300 - (15ms + 5ms just in case)
+
+	ch1.close()
+	ch2.close()
+	mut h := 7
+	mut is_open := true
+	if select {
+		_ := <-ch2 {
+			h = 0
+		}
+		ch1 <- h {
+			h = 1
+		}
+		else {
+			h = 2
+		}
+	} {
+		panic('channel is still open')
+	} else {
+		is_open = false
+	}
+	// no branch should have run
+	assert h == 7
+	// since all channels are closed `select` should return `false`
+	assert is_open == false
+}