Adds most of the toolsHEADmaster

1 files changed, 42 insertions, 0 deletions

diff --git a/v_windows/v/vlib/context/cancel_test.v b/v_windows/v/vlib/context/cancel_test.v
new file mode 100644
index 0000000..6b9fdaa
--- /dev/null
+++ b/v_windows/v/vlib/context/cancel_test.v
@@ -0,0 +1,42 @@
+import context
+
+// This example demonstrates the use of a cancelable context to prevent a
+// routine leak. By the end of the example function, the routine started
+// by gen will return without leaking.
+fn test_with_cancel() {
+	// gen generates integers in a separate routine and
+	// sends them to the returned channel.
+	// The callers of gen need to cancel the context once
+	// they are done consuming generated integers not to leak
+	// the internal routine started by gen.
+	gen := fn (ctx context.Context) chan int {
+		dst := chan int{}
+		go fn (ctx context.Context, dst chan int) {
+			mut v := 0
+			ch := ctx.done()
+			for {
+				select {
+					_ := <-ch {
+						// returning not to leak the routine
+						return
+					}
+					dst <- v {
+						v++
+					}
+				}
+			}
+		}(ctx, dst)
+		return dst
+	}
+
+	ctx := context.with_cancel(context.background())
+	defer {
+		context.cancel(ctx)
+	}
+
+	ch := gen(ctx)
+	for i in 0 .. 5 {
+		v := <-ch
+		assert i == v
+	}
+}