Move stack.fakeClock into a separate package

PiperOrigin-RevId: 333138701

1 files changed, 95 insertions, 0 deletions

diff --git a/pkg/tcpip/faketime/faketime_test.go b/pkg/tcpip/faketime/faketime_test.go
new file mode 100644
index 000000000..c2704df2c
--- /dev/null
+++ b/pkg/tcpip/faketime/faketime_test.go
@@ -0,0 +1,95 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package faketime_test
+
+import (
+	"testing"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/tcpip/faketime"
+)
+
+func TestManualClockAdvance(t *testing.T) {
+	const timeout = time.Millisecond
+	clock := faketime.NewManualClock()
+	start := clock.NowMonotonic()
+	clock.Advance(timeout)
+	if got, want := time.Duration(clock.NowMonotonic()-start)*time.Nanosecond, timeout; got != want {
+		t.Errorf("got = %d, want = %d", got, want)
+	}
+}
+
+func TestManualClockAfterFunc(t *testing.T) {
+	const (
+		timeout1 = time.Millisecond     // timeout for counter1
+		timeout2 = 2 * time.Millisecond // timeout for counter2
+	)
+	tests := []struct {
+		name         string
+		advance      time.Duration
+		wantCounter1 int
+		wantCounter2 int
+	}{
+		{
+			name:         "before timeout1",
+			advance:      timeout1 - 1,
+			wantCounter1: 0,
+			wantCounter2: 0,
+		},
+		{
+			name:         "timeout1",
+			advance:      timeout1,
+			wantCounter1: 1,
+			wantCounter2: 0,
+		},
+		{
+			name:         "timeout2",
+			advance:      timeout2,
+			wantCounter1: 1,
+			wantCounter2: 1,
+		},
+		{
+			name:         "after timeout2",
+			advance:      timeout2 + 1,
+			wantCounter1: 1,
+			wantCounter2: 1,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			clock := faketime.NewManualClock()
+			counter1 := 0
+			counter2 := 0
+			clock.AfterFunc(timeout1, func() {
+				counter1++
+			})
+			clock.AfterFunc(timeout2, func() {
+				counter2++
+			})
+			start := clock.NowMonotonic()
+			clock.Advance(test.advance)
+			if got, want := counter1, test.wantCounter1; got != want {
+				t.Errorf("got counter1 = %d, want = %d", got, want)
+			}
+			if got, want := counter2, test.wantCounter2; got != want {
+				t.Errorf("got counter2 = %d, want = %d", got, want)
+			}
+			if got, want := time.Duration(clock.NowMonotonic()-start)*time.Nanosecond, test.advance; got != want {
+				t.Errorf("got elapsed = %d, want = %d", got, want)
+			}
+		})
+	}
+}