Add context-aware "time" library wrapper.

go/src/infra/libs/clock/testclock/testtimer_test.go

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package testclock
+
+import (
+        "testing"
+        "time"
+
+        . "github.com/smartystreets/goconvey/convey"
+        "infra/libs/clock"
+)
+
+func TestTestTimer(t *testing.T) {
+        Convey(`A testing clock instance`, t, func() {
+                now := time.Date(2015, 01, 01, 00, 00, 00, 00, time.UTC)
+                c := New(now)
+
+                Convey(`A timer instance`, func() {
+                        t := c.NewTimer()
+
+                        Convey(`Should have a non-nil C.`, func() {
+                                So(t.GetC(), ShouldBeNil)
+                        })
+
+                        Convey(`When activated`, func() {
+                                So(t.Reset(1*time.Second), ShouldBeFalse)
+
+                                Convey(`When reset, should return active.`, func() {
+                                        So(t.Reset(1*time.Hour), ShouldBeTrue)
+                                        So(t.GetC(), ShouldNotBeNil)
+                                })
+
+                                Convey(`When stopped, should return active.`, func() {
+                                        So(t.Stop(), ShouldBeTrue)
+                                        So(t.GetC(), ShouldBeNil)
+
+                                        Convey(`And when stopped again, should return inactive.`, func() {
+                                                So(t.Stop(), ShouldBeFalse)
+                                                So(t.GetC(), ShouldBeNil)
+                                        })
+                                })
+
+                                Convey(`When stopped after expiring, should not have a signal.`, func() {
+                                        c.Add(1 * time.Second)
+                                        So(t.Stop(), ShouldBeTrue)
+
+                                        var signalled bool
+                                        select {
+                                        case <-t.GetC():
+                                                signalled = true
+                                        default:
+                                                break
+                                        }
+                                        So(signalled, ShouldBeFalse)
+                                })
+                        })
+
+                        Convey(`Should successfully signal.`, func() {
+                                So(t.Reset(1*time.Second), ShouldBeFalse)
+                                c.Add(1 * time.Second)
+
+                                So(t.GetC(), ShouldNotBeNil)
+                                So(<-t.GetC(), ShouldResemble, now.Add(1*time.Second))
+                        })
+                })
+
+                Convey(`Multiple goroutines using the timer...`, func() {
+                        // Mark when timers are started, so we can ensure that our signalling
+                        // happens after the timers have been instantiated.
+                        timerStartedC := make(chan bool)
+                        c.SetTimerCallback(func(_ clock.Timer) {
+                                timerStartedC <- true
+                        })
+
+                        resultC := make(chan time.Time)
+                        for i := time.Duration(0); i < 5; i++ {
+                                go func(d time.Duration) {
+                                        timer := c.NewTimer()
+                                        timer.Reset(d)
+                                        resultC <- <-timer.GetC()
+                                }(i * time.Second)
+                                <-timerStartedC
+                        }
+
+                        moreResults := func() bool {
+                                select {
+                                case <-resultC:
+                                        return true
+                                default:
+                                        return false
+                                }
+                        }
+
+                        // Advance the clock to +2s. Three timers should signal.
+                        c.Set(now.Add(2 * time.Second))
+                        <-resultC
+                        <-resultC
+                        <-resultC
+                        So(moreResults(), ShouldBeFalse)
+
+                        // Advance clock to +3s. One timer should signal.
+                        c.Set(now.Add(3 * time.Second))
+                        <-resultC
+                        So(moreResults(), ShouldBeFalse)
+
+                        // Advance clock to +10s. One final timer should signal.
+                        c.Set(now.Add(10 * time.Second))
+                        <-resultC
+                        So(moreResults(), ShouldBeFalse)
+                })
+        })
+}