/usr/share/gocode/src/github.com/jonboulle/clockwork/clockwork.go is in golang-github-jonboulle-clockwork-dev 0.1.0-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 | package clockwork
import (
"sync"
"time"
)
// Clock provides an interface that packages can use instead of directly
// using the time module, so that chronology-related behavior can be tested
type Clock interface {
After(d time.Duration) <-chan time.Time
Sleep(d time.Duration)
Now() time.Time
}
// FakeClock provides an interface for a clock which can be
// manually advanced through time
type FakeClock interface {
Clock
// Advance advances the FakeClock to a new point in time, ensuring any existing
// sleepers are notified appropriately before returning
Advance(d time.Duration)
// BlockUntil will block until the FakeClock has the given number of
// sleepers (callers of Sleep or After)
BlockUntil(n int)
}
// NewRealClock returns a Clock which simply delegates calls to the actual time
// package; it should be used by packages in production.
func NewRealClock() Clock {
return &realClock{}
}
// NewFakeClock returns a FakeClock implementation which can be
// manually advanced through time for testing. The initial time of the
// FakeClock will be an arbitrary non-zero time.
func NewFakeClock() FakeClock {
// use a fixture that does not fulfill Time.IsZero()
return NewFakeClockAt(time.Date(1984, time.April, 4, 0, 0, 0, 0, time.UTC))
}
// NewFakeClockAt returns a FakeClock initialised at the given time.Time.
func NewFakeClockAt(t time.Time) FakeClock {
return &fakeClock{
time: t,
}
}
type realClock struct{}
func (rc *realClock) After(d time.Duration) <-chan time.Time {
return time.After(d)
}
func (rc *realClock) Sleep(d time.Duration) {
time.Sleep(d)
}
func (rc *realClock) Now() time.Time {
return time.Now()
}
type fakeClock struct {
sleepers []*sleeper
blockers []*blocker
time time.Time
l sync.RWMutex
}
// sleeper represents a caller of After or Sleep
type sleeper struct {
until time.Time
done chan time.Time
}
// blocker represents a caller of BlockUntil
type blocker struct {
count int
ch chan struct{}
}
// After mimics time.After; it waits for the given duration to elapse on the
// fakeClock, then sends the current time on the returned channel.
func (fc *fakeClock) After(d time.Duration) <-chan time.Time {
fc.l.Lock()
defer fc.l.Unlock()
now := fc.time
done := make(chan time.Time, 1)
if d.Nanoseconds() == 0 {
// special case - trigger immediately
done <- now
} else {
// otherwise, add to the set of sleepers
s := &sleeper{
until: now.Add(d),
done: done,
}
fc.sleepers = append(fc.sleepers, s)
// and notify any blockers
fc.blockers = notifyBlockers(fc.blockers, len(fc.sleepers))
}
return done
}
// notifyBlockers notifies all the blockers waiting until the
// given number of sleepers are waiting on the fakeClock. It
// returns an updated slice of blockers (i.e. those still waiting)
func notifyBlockers(blockers []*blocker, count int) (newBlockers []*blocker) {
for _, b := range blockers {
if b.count == count {
close(b.ch)
} else {
newBlockers = append(newBlockers, b)
}
}
return
}
// Sleep blocks until the given duration has passed on the fakeClock
func (fc *fakeClock) Sleep(d time.Duration) {
<-fc.After(d)
}
// Time returns the current time of the fakeClock
func (fc *fakeClock) Now() time.Time {
fc.l.RLock()
t := fc.time
fc.l.RUnlock()
return t
}
// Advance advances fakeClock to a new point in time, ensuring channels from any
// previous invocations of After are notified appropriately before returning
func (fc *fakeClock) Advance(d time.Duration) {
fc.l.Lock()
defer fc.l.Unlock()
end := fc.time.Add(d)
var newSleepers []*sleeper
for _, s := range fc.sleepers {
if end.Sub(s.until) >= 0 {
s.done <- end
} else {
newSleepers = append(newSleepers, s)
}
}
fc.sleepers = newSleepers
fc.blockers = notifyBlockers(fc.blockers, len(fc.sleepers))
fc.time = end
}
// BlockUntil will block until the fakeClock has the given number of sleepers
// (callers of Sleep or After)
func (fc *fakeClock) BlockUntil(n int) {
fc.l.Lock()
// Fast path: current number of sleepers is what we're looking for
if len(fc.sleepers) == n {
fc.l.Unlock()
return
}
// Otherwise, set up a new blocker
b := &blocker{
count: n,
ch: make(chan struct{}),
}
fc.blockers = append(fc.blockers, b)
fc.l.Unlock()
<-b.ch
}
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