Add monitoring for original context in extendedConnection struct

[NikitaSkrynnik]

Description

Add monitoring of original context canceling in extendedConnection

Issue

networkservicemesh/cmd-forwarder-vpp#1133

[denis-tingaikin]

I think we can simplify it. Thoughts?

diff --git a/extendtimeout/connection.go b/extendtimeout/connection.go
index 288a872..e34a6f4 100644
--- a/extendtimeout/connection.go
+++ b/extendtimeout/connection.go
@@ -21,7 +21,6 @@ import (
 	"context"
 	"time"
 
-	"github.com/edwarnicke/log"
 	"go.fd.io/govpp/api"
 )
 
@@ -48,27 +47,26 @@ func NewConnection(vppConn api.Connection, contextTimeout time.Duration) api.Con
 }
 
 func (c *extendedConnection) Invoke(ctx context.Context, req, reply api.Message) error {
-	ctx, cancel := c.withExtendedTimeoutCtx(ctx)
+	ctx, cancel := c.withExtenedTimeoutContext(ctx)
 	err := c.Connection.Invoke(ctx, req, reply)
 	cancel()
 	return err
 }
 
-func (c *extendedConnection) withExtendedTimeoutCtx(ctx context.Context) (extendedCtx context.Context, cancel func()) {
-	deadline, ok := ctx.Deadline()
-	if !ok {
-		return ctx, func() {}
-	}
+func(c *extendedConnection) withExtenedTimeoutContext(ctx context.Context) (context.Context, context.CancelFunc) {
+	var cancelContext, cancel = context.WithCancel(context.Background())
+	var timeoutContext, timeoutCancel = context.WithTimeout(cancelContext, c.contextTimeout)
+	go func() {
+		<-timeoutContext.Done()
+		timeoutCancel()
+		select {
+		case <-cancelContext.Done():
+			return
+		case <-ctx.Done():
+			cancel()
+			return
+		}
+	}()
 
-	minDeadline := time.Now().Add(c.contextTimeout)
-	if minDeadline.Before(deadline) {
-		return ctx, func() {}
-	}
-	log.Entry(ctx).Warnf("Context deadline has been extended by extendtimeout from %v to %v", deadline, minDeadline)
-	deadline = minDeadline
-	postponedCtx, cancel := context.WithDeadline(context.Background(), deadline)
-	return &extendedContext{
-		Context:       postponedCtx,
-		valuesContext: ctx,
-	}, cancel
+	return cancelContext, cancel
 }
diff --git a/extendtimeout/connection_test.go b/extendtimeout/connection_test.go
index 4d0025e..7af4f30 100644
--- a/extendtimeout/connection_test.go
+++ b/extendtimeout/connection_test.go
@@ -39,44 +39,6 @@ func (c *testConn) Invoke(ctx context.Context, req, reply api.Message) error {
 	return nil
 }
 
-type key struct{}
-
-const value = "value"
-
-func TestSmallTimeout(t *testing.T) {
-	testConn := &testConn{invokeBody: func(ctx context.Context) {
-		deadline, ok := ctx.Deadline()
-		require.True(t, ok)
-		timeout := time.Until(deadline)
-		require.Greater(t, timeout, time.Second)
-		require.Equal(t, ctx.Value(&key{}), value)
-	}}
-
-	smallCtx, cancel := context.WithTimeout(context.Background(), time.Millisecond*10)
-	smallCtx = context.WithValue(smallCtx, &key{}, value)
-	defer cancel()
-
-	err := extendtimeout.NewConnection(testConn, 2*time.Second).Invoke(smallCtx, nil, nil)
-	require.NoError(t, err)
-}
-
-func TestBigTimeout(t *testing.T) {
-	testConn := &testConn{invokeBody: func(ctx context.Context) {
-		deadline, ok := ctx.Deadline()
-		require.True(t, ok)
-		timeout := time.Until(deadline)
-		require.Greater(t, timeout, 7*time.Second)
-		require.Equal(t, ctx.Value(&key{}), value)
-	}}
-
-	bigCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	bigCtx = context.WithValue(bigCtx, &key{}, value)
-	defer cancel()
-
-	err := extendtimeout.NewConnection(testConn, 2*time.Second).Invoke(bigCtx, nil, nil)
-	require.NoError(t, err)
-}
-
 func TestNoTimeout(t *testing.T) {
 	testConn := &testConn{invokeBody: func(ctx context.Context) {
 		_, ok := ctx.Deadline()