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Diffstat (limited to 'kube2msb/src/vendor/github.com/jonboulle/clockwork/clockwork.go')
-rw-r--r-- | kube2msb/src/vendor/github.com/jonboulle/clockwork/clockwork.go | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/kube2msb/src/vendor/github.com/jonboulle/clockwork/clockwork.go b/kube2msb/src/vendor/github.com/jonboulle/clockwork/clockwork.go new file mode 100644 index 0000000..1f1045b --- /dev/null +++ b/kube2msb/src/vendor/github.com/jonboulle/clockwork/clockwork.go @@ -0,0 +1,164 @@ +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. +func NewFakeClock() FakeClock { + return &fakeClock{ + l: sync.RWMutex{}, + + // use a fixture that does not fulfill Time.IsZero() + time: time.Date(1900, time.January, 1, 0, 0, 0, 0, time.UTC), + } +} + +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.Lock() + defer fc.l.Unlock() + return fc.time +} + +// 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 +} |