Merge pull request #1021 from jonboulle/clock

Implement fake clock for testing

Godeps/Godeps.json

@@ -14,6 +14,10 @@
 			"ImportPath": "code.google.com/p/gogoprotobuf/proto",
 			"Rev": "7fd1620f09261338b6b1ca1289ace83aee0ec946"
 		},
+		{
+			"ImportPath": "github.com/jonboulle/clockwork",
+			"Rev": "72f9bd7c4e0c2a40055ab3d0f09654f730cce982"
+		},
 		{
 			"ImportPath": "github.com/stretchr/testify/assert",
 			"Rev": "9cc77fa25329013ce07362c7742952ff887361f2"

Godeps/_workspace/src/github.com/jonboulle/clockwork/.gitignore

@@ -0,0 +1,25 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+
+*.swp

Godeps/_workspace/src/github.com/jonboulle/clockwork/LICENSE

@@ -0,0 +1,201 @@
+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   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.

Godeps/_workspace/src/github.com/jonboulle/clockwork/README.md

@@ -0,0 +1,58 @@
+clockwork
+=========
+
+a simple fake clock for golang
+
+# Usage
+
+Replace uses of the `time` package with the `clockwork.Clock` interface instead.
+
+For example, instead of using `time.Sleep` directly:
+
+```
+func my_func() {
+	time.Sleep(3 * time.Second)
+	do_something()
+}
+```
+
+inject a clock and use its `Sleep` method instead:
+
+```
+func my_func(clock clockwork.Clock) {
+	clock.Sleep(3 * time.Second)
+	do_something()
+}
+```
+
+Now you can easily test `my_func` with a `FakeClock`:
+
+```
+func TestMyFunc(t *testing.T) {
+	c := clockwork.NewFakeClock()
+
+	// Start our sleepy function
+	my_func(c)
+
+	// Ensure we wait until my_func is sleeping
+	c.BlockUntil(1)
+
+	assert_state()
+
+	// Advance the FakeClock forward in time
+	c.Advance(3)
+
+	assert_state()
+}
+```
+
+and in production builds, simply inject the real clock instead:
+```
+my_func(clockwork.NewRealClock())
+```
+
+See [example_test.go](example_test.go) for a full example.
+
+# Credits
+
+Inspired by @wickman's [threaded fake clock](https://gist.github.com/wickman/3840816), and the [Golang playground](http://blog.golang.org/playground#Faking time)

Godeps/_workspace/src/github.com/jonboulle/clockwork/clockwork.go

@@ -0,0 +1,161 @@
+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{},
+	}
+}
+
+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
+}

Godeps/_workspace/src/github.com/jonboulle/clockwork/clockwork_test.go

@@ -0,0 +1,106 @@
+package clockwork
+
+import (
+	"testing"
+	"time"
+)
+
+func TestFakeClockAfter(t *testing.T) {
+	fc := &fakeClock{}
+
+	zero := fc.After(0)
+	select {
+	case <-zero:
+	default:
+		t.Errorf("zero did not return!")
+	}
+	one := fc.After(1)
+	two := fc.After(2)
+	six := fc.After(6)
+	ten := fc.After(10)
+	fc.Advance(1)
+	select {
+	case <-one:
+	default:
+		t.Errorf("one did not return!")
+	}
+	select {
+	case <-two:
+		t.Errorf("two returned prematurely!")
+	case <-six:
+		t.Errorf("six returned prematurely!")
+	case <-ten:
+		t.Errorf("ten returned prematurely!")
+	default:
+	}
+	fc.Advance(1)
+	select {
+	case <-two:
+	default:
+		t.Errorf("two did not return!")
+	}
+	select {
+	case <-six:
+		t.Errorf("six returned prematurely!")
+	case <-ten:
+		t.Errorf("ten returned prematurely!")
+	default:
+	}
+	fc.Advance(1)
+	select {
+	case <-six:
+		t.Errorf("six returned prematurely!")
+	case <-ten:
+		t.Errorf("ten returned prematurely!")
+	default:
+	}
+	fc.Advance(3)
+	select {
+	case <-six:
+	default:
+		t.Errorf("six did not return!")
+	}
+	select {
+	case <-ten:
+		t.Errorf("ten returned prematurely!")
+	default:
+	}
+	fc.Advance(100)
+	select {
+	case <-ten:
+	default:
+		t.Errorf("ten did not return!")
+	}
+}
+
+func TestNotifyBlockers(t *testing.T) {
+	b1 := &blocker{1, make(chan struct{})}
+	b2 := &blocker{2, make(chan struct{})}
+	b3 := &blocker{5, make(chan struct{})}
+	b4 := &blocker{10, make(chan struct{})}
+	b5 := &blocker{10, make(chan struct{})}
+	bs := []*blocker{b1, b2, b3, b4, b5}
+	bs1 := notifyBlockers(bs, 2)
+	if n := len(bs1); n != 4 {
+		t.Fatalf("got %d blockers, want %d", n, 4)
+	}
+	select {
+	case <-b2.ch:
+	case <-time.After(time.Second):
+		t.Fatalf("timed out waiting for channel close!")
+	}
+	bs2 := notifyBlockers(bs1, 10)
+	if n := len(bs2); n != 2 {
+		t.Fatalf("got %d blockers, want %d", n, 2)
+	}
+	select {
+	case <-b4.ch:
+	case <-time.After(time.Second):
+		t.Fatalf("timed out waiting for channel close!")
+	}
+	select {
+	case <-b5.ch:
+	case <-time.After(time.Second):
+		t.Fatalf("timed out waiting for channel close!")
+	}
+}

Godeps/_workspace/src/github.com/jonboulle/clockwork/example_test.go

@@ -0,0 +1,49 @@
+package clockwork
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+// my_func is an example of a time-dependent function, using an
+// injected clock
+func my_func(clock Clock, i *int) {
+	clock.Sleep(3 * time.Second)
+	*i += 1
+}
+
+// assert_state is an example of a state assertion in a test
+func assert_state(t *testing.T, i, j int) {
+	if i != j {
+		t.Fatalf("i %d, j %d", i, j)
+	}
+}
+
+// TestMyFunc tests my_func's behaviour with a FakeClock
+func TestMyFunc(t *testing.T) {
+	var i int
+	c := NewFakeClock()
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		my_func(c, &i)
+		wg.Done()
+	}()
+
+	// Wait until my_func is actually sleeping on the clock
+	c.BlockUntil(1)
+
+	// Assert the initial state
+	assert_state(t, i, 0)
+
+	// Now advance the clock forward in time
+	c.Advance(1 * time.Hour)
+
+	// Wait until the function completes
+	wg.Wait()
+
+	// Assert the final state
+	assert_state(t, i, 1)
+}

discovery/discovery.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	"github.com/coreos/etcd/client"
 )
 
@@ -45,8 +46,7 @@ type discovery struct {
 	retries uint
 	url     *url.URL
 
-	// Injectable for testing. nil means Seconds.
-	timeoutTimescale time.Duration
+	clock clockwork.Clock
 }
 
 // proxyFuncFromEnv builds a proxy function if the appropriate environment
@@ -97,12 +97,12 @@ func New(durl string, id uint64, config string) (Discoverer, error) {
 	// set the prefix of client to "" to handle this
 	c.SetPrefix("")
 	return &discovery{
-		cluster:          token,
-		id:               id,
-		config:           config,
-		c:                c,
-		url:              u,
-		timeoutTimescale: time.Second,
+		cluster: token,
+		id:      id,
+		config:  config,
+		c:       c,
+		url:     u,
+		clock:   clockwork.NewRealClock(),
 	}, nil
 }
 
@@ -196,9 +196,9 @@ func (d *discovery) checkCluster() (client.Nodes, int, error) {
 
 func (d *discovery) logAndBackoffForRetry(step string) {
 	d.retries++
-	retryTime := d.timeoutTimescale * (0x1 << d.retries)
+	retryTime := time.Second * (0x1 << d.retries)
 	log.Println("discovery: during", step, "connection to", d.url, "timed out, retrying in", retryTime)
-	time.Sleep(retryTime)
+	d.clock.Sleep(retryTime)
 }
 
 func (d *discovery) checkClusterRetry() (client.Nodes, int, error) {

discovery/discovery_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	"github.com/coreos/etcd/client"
 )
 
@@ -167,9 +168,16 @@ func TestCheckCluster(t *testing.T) {
 
 		cRetry := &clientWithRetry{failTimes: 3}
 		cRetry.rs = rs
-		dRetry := discovery{cluster: cluster, id: 1, c: cRetry, timeoutTimescale: time.Millisecond * 2}
+		fc := clockwork.NewFakeClock()
+		dRetry := discovery{cluster: cluster, id: 1, c: cRetry, clock: fc}
 
 		for _, d := range []discovery{d, dRetry} {
+			go func() {
+				for i := uint(1); i <= nRetries; i++ {
+					fc.BlockUntil(1)
+					fc.Advance(time.Second * (0x1 << i))
+				}
+			}()
 			ns, size, err := d.checkCluster()
 			if err != tt.werr {
 				t.Errorf("#%d: err = %v, want %v", i, err, tt.werr)
@@ -193,46 +201,30 @@ func TestWaitNodes(t *testing.T) {
 
 	tests := []struct {
 		nodes client.Nodes
-		size  int
 		rs    []*client.Response
-
-		werr error
-		wall client.Nodes
 	}{
 		{
 			all,
-			3,
 			[]*client.Response{},
-			nil,
-			all,
 		},
 		{
 			all[:1],
-			3,
 			[]*client.Response{
 				{Node: &client.Node{Key: "/1000/2", CreatedIndex: 3}},
 				{Node: &client.Node{Key: "/1000/3", CreatedIndex: 4}},
 			},
-			nil,
-			all,
 		},
 		{
 			all[:2],
-			3,
 			[]*client.Response{
 				{Node: &client.Node{Key: "/1000/3", CreatedIndex: 4}},
 			},
-			nil,
-			all,
 		},
 		{
 			append(all, &client.Node{Key: "/1000/4", CreatedIndex: 5}),
-			3,
 			[]*client.Response{
 				{Node: &client.Node{Key: "/1000/3", CreatedIndex: 4}},
 			},
-			nil,
-			all,
 		},
 	}
 
@@ -247,7 +239,7 @@ func TestWaitNodes(t *testing.T) {
 			retryScanResp = append(retryScanResp, &client.Response{
 				Node: &client.Node{
 					Key:   "1000",
-					Value: strconv.Itoa(tt.size),
+					Value: strconv.Itoa(3),
 				},
 			})
 			retryScanResp = append(retryScanResp, &client.Response{
@@ -260,19 +252,26 @@ func TestWaitNodes(t *testing.T) {
 			rs: retryScanResp,
 			w:  &watcherWithRetry{rs: tt.rs, failTimes: 2},
 		}
+		fc := clockwork.NewFakeClock()
 		dRetry := &discovery{
-			cluster:          "1000",
-			c:                cRetry,
-			timeoutTimescale: time.Millisecond * 2,
+			cluster: "1000",
+			c:       cRetry,
+			clock:   fc,
 		}
 
 		for _, d := range []*discovery{d, dRetry} {
-			g, err := d.waitNodes(tt.nodes, tt.size)
-			if err != tt.werr {
-				t.Errorf("#%d: err = %v, want %v", i, err, tt.werr)
+			go func() {
+				for i := uint(1); i <= nRetries; i++ {
+					fc.BlockUntil(1)
+					fc.Advance(time.Second * (0x1 << i))
+				}
+			}()
+			g, err := d.waitNodes(tt.nodes, 3)
+			if err != nil {
+				t.Errorf("#%d: err = %v, want %v", i, err, nil)
 			}
-			if !reflect.DeepEqual(g, tt.wall) {
-				t.Errorf("#%d: all = %v, want %v", i, g, tt.wall)
+			if !reflect.DeepEqual(g, all) {
+				t.Errorf("#%d: all = %v, want %v", i, g, all)
 			}
 		}
 	}
@@ -354,9 +353,20 @@ func TestSortableNodes(t *testing.T) {
 func TestRetryFailure(t *testing.T) {
 	cluster := "1000"
 	c := &clientWithRetry{failTimes: 4}
-	d := discovery{cluster: cluster, id: 1, c: c, timeoutTimescale: time.Millisecond * 2}
-	_, _, err := d.checkCluster()
-	if err != ErrTooManyRetries {
+	fc := clockwork.NewFakeClock()
+	d := discovery{
+		cluster: cluster,
+		id:      1,
+		c:       c,
+		clock:   fc,
+	}
+	go func() {
+		for i := uint(1); i <= nRetries; i++ {
+			fc.BlockUntil(1)
+			fc.Advance(time.Second * (0x1 << i))
+		}
+	}()
+	if _, _, err := d.checkCluster(); err != ErrTooManyRetries {
 		t.Errorf("err = %v, want %v", err, ErrTooManyRetries)
 	}
 }
@@ -434,7 +444,7 @@ func (w *watcherWithErr) Next() (*client.Response, error) {
 	return &client.Response{}, w.err
 }
 
-// Fails every other time
+// clientWithRetry will timeout all requests up to failTimes
 type clientWithRetry struct {
 	clientWithResp
 	failCount int
@@ -457,6 +467,7 @@ func (c *clientWithRetry) Get(key string) (*client.Response, error) {
 	return c.clientWithResp.Get(key)
 }
 
+// watcherWithRetry will timeout all requests up to failTimes
 type watcherWithRetry struct {
 	rs        []*client.Response
 	failCount int

etcdserver/etcdhttp/http.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	etcdErr "github.com/coreos/etcd/error"
 	"github.com/coreos/etcd/etcdserver"
 	"github.com/coreos/etcd/etcdserver/etcdserverpb"
@@ -89,7 +90,7 @@ func (h serverHandler) serveKeys(w http.ResponseWriter, r *http.Request) {
 	ctx, cancel := context.WithTimeout(context.Background(), h.timeout)
 	defer cancel()
 
-	rr, err := parseRequest(r, etcdserver.GenID())
+	rr, err := parseRequest(r, etcdserver.GenID(), clockwork.NewRealClock())
 	if err != nil {
 		writeError(w, err)
 		return
@@ -225,7 +226,7 @@ func (h serverHandler) serveRaft(w http.ResponseWriter, r *http.Request) {
 // parseRequest converts a received http.Request to a server Request,
 // performing validation of supplied fields as appropriate.
 // If any validation fails, an empty Request and non-nil error is returned.
-func parseRequest(r *http.Request, id uint64) (etcdserverpb.Request, error) {
+func parseRequest(r *http.Request, id uint64, clock clockwork.Clock) (etcdserverpb.Request, error) {
 	emptyReq := etcdserverpb.Request{}
 
 	err := r.ParseForm()
@@ -354,11 +355,9 @@ func parseRequest(r *http.Request, id uint64) (etcdserverpb.Request, error) {
 	}
 
 	// Null TTL is equivalent to unset Expiration
-	// TODO(jonboulle): use fake clock instead of time module
-	// https://github.com/coreos/etcd/issues/1021
 	if ttl != nil {
 		expr := time.Duration(*ttl) * time.Second
-		rr.Expiration = time.Now().Add(expr).UnixNano()
+		rr.Expiration = clock.Now().Add(expr).UnixNano()
 	}
 
 	return rr, nil

etcdserver/etcdhttp/http_test.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/code.google.com/p/go.net/context"
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	etcdErr "github.com/coreos/etcd/error"
 	"github.com/coreos/etcd/etcdserver"
 	"github.com/coreos/etcd/etcdserver/etcdserverpb"
@@ -194,7 +195,7 @@ func TestBadParseRequest(t *testing.T) {
 		},
 	}
 	for i, tt := range tests {
-		got, err := parseRequest(tt.in, 1234)
+		got, err := parseRequest(tt.in, 1234, clockwork.NewFakeClock())
 		if err == nil {
 			t.Errorf("#%d: unexpected nil error!", i)
 			continue
@@ -215,6 +216,8 @@ func TestBadParseRequest(t *testing.T) {
 }
 
 func TestGoodParseRequest(t *testing.T) {
+	fc := clockwork.NewFakeClock()
+	fc.Advance(1111)
 	tests := []struct {
 		in *http.Request
 		w  etcdserverpb.Request
@@ -304,6 +307,26 @@ func TestGoodParseRequest(t *testing.T) {
 				Expiration: 0,
 			},
 		},
+		{
+			// non-empty TTL specified
+			mustNewRequest(t, "foo?ttl=5678"),
+			etcdserverpb.Request{
+				ID:         1234,
+				Method:     "GET",
+				Path:       "/foo",
+				Expiration: fc.Now().Add(5678 * time.Second).UnixNano(),
+			},
+		},
+		{
+			// zero TTL specified
+			mustNewRequest(t, "foo?ttl=0"),
+			etcdserverpb.Request{
+				ID:         1234,
+				Method:     "GET",
+				Path:       "/foo",
+				Expiration: fc.Now().UnixNano(),
+			},
+		},
 		{
 			// dir specified
 			mustNewRequest(t, "foo?dir=true"),
@@ -405,7 +428,7 @@ func TestGoodParseRequest(t *testing.T) {
 	}
 
 	for i, tt := range tests {
-		got, err := parseRequest(tt.in, 1234)
+		got, err := parseRequest(tt.in, 1234, fc)
 		if err != nil {
 			t.Errorf("#%d: err = %v, want %v", i, err, nil)
 		}
@@ -413,27 +436,6 @@ func TestGoodParseRequest(t *testing.T) {
 			t.Errorf("#%d: request=%#v, want %#v", i, got, tt.w)
 		}
 	}
-
-	// Test TTL separately until we don't rely on the time module...
-	now := time.Now().UnixNano()
-	req := mustNewForm(t, "foo", url.Values{"ttl": []string{"100"}})
-	got, err := parseRequest(req, 1234)
-	if err != nil {
-		t.Fatalf("err = %v, want nil", err)
-	}
-	if got.Expiration <= now {
-		t.Fatalf("expiration = %v, wanted > %v", got.Expiration, now)
-	}
-
-	// ensure TTL=0 results in an expiration time
-	req = mustNewForm(t, "foo", url.Values{"ttl": []string{"0"}})
-	got, err = parseRequest(req, 1234)
-	if err != nil {
-		t.Fatalf("err = %v, want nil", err)
-	}
-	if got.Expiration <= now {
-		t.Fatalf("expiration = %v, wanted > %v", got.Expiration, now)
-	}
 }
 
 // eventingWatcher immediately returns a simple event of the given action on its channel

store/node.go

@@ -5,6 +5,7 @@ import (
 	"sort"
 	"time"
 
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	etcdErr "github.com/coreos/etcd/error"
 )
 
@@ -119,7 +120,7 @@ func (n *node) Write(value string, index uint64) *etcdErr.Error {
 	return nil
 }
 
-func (n *node) ExpirationAndTTL() (*time.Time, int64) {
+func (n *node) expirationAndTTL(clock clockwork.Clock) (*time.Time, int64) {
 	if !n.IsPermanent() {
 		/* compute ttl as:
 		   ceiling( (expireTime - timeNow) / nanosecondsPerSecond )
@@ -128,7 +129,7 @@ func (n *node) ExpirationAndTTL() (*time.Time, int64) {
 		   ( (expireTime - timeNow) / nanosecondsPerSecond ) + 1
 		   which ranges 1..n+1
 		*/
-		ttlN := n.ExpireTime.Sub(time.Now())
+		ttlN := n.ExpireTime.Sub(clock.Now())
 		ttl := ttlN / time.Second
 		if (ttlN % time.Second) > 0 {
 			ttl++
@@ -251,7 +252,7 @@ func (n *node) Remove(dir, recursive bool, callback func(path string)) *etcdErr.
 	return nil
 }
 
-func (n *node) Repr(recursive, sorted bool) *NodeExtern {
+func (n *node) Repr(recursive, sorted bool, clock clockwork.Clock) *NodeExtern {
 	if n.IsDir() {
 		node := &NodeExtern{
 			Key:           n.Path,
@@ -259,7 +260,7 @@ func (n *node) Repr(recursive, sorted bool) *NodeExtern {
 			ModifiedIndex: n.ModifiedIndex,
 			CreatedIndex:  n.CreatedIndex,
 		}
-		node.Expiration, node.TTL = n.ExpirationAndTTL()
+		node.Expiration, node.TTL = n.expirationAndTTL(clock)
 
 		if !recursive {
 			return node
@@ -278,7 +279,7 @@ func (n *node) Repr(recursive, sorted bool) *NodeExtern {
 				continue
 			}
 
-			node.Nodes[i] = child.Repr(recursive, sorted)
+			node.Nodes[i] = child.Repr(recursive, sorted, clock)
 
 			i++
 		}
@@ -300,7 +301,7 @@ func (n *node) Repr(recursive, sorted bool) *NodeExtern {
 		ModifiedIndex: n.ModifiedIndex,
 		CreatedIndex:  n.CreatedIndex,
 	}
-	node.Expiration, node.TTL = n.ExpirationAndTTL()
+	node.Expiration, node.TTL = n.expirationAndTTL(clock)
 	return node
 }
 

store/node_extern.go

@@ -3,6 +3,8 @@ package store
 import (
 	"sort"
 	"time"
+
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 )
 
 // NodeExtern is the external representation of the
@@ -20,7 +22,7 @@ type NodeExtern struct {
 	CreatedIndex  uint64      `json:"createdIndex,omitempty"`
 }
 
-func (eNode *NodeExtern) loadInternalNode(n *node, recursive, sorted bool) {
+func (eNode *NodeExtern) loadInternalNode(n *node, recursive, sorted bool, clock clockwork.Clock) {
 	if n.IsDir() { // node is a directory
 		eNode.Dir = true
 
@@ -36,7 +38,7 @@ func (eNode *NodeExtern) loadInternalNode(n *node, recursive, sorted bool) {
 				continue
 			}
 
-			eNode.Nodes[i] = child.Repr(recursive, sorted)
+			eNode.Nodes[i] = child.Repr(recursive, sorted, clock)
 			i++
 		}
 
@@ -52,7 +54,7 @@ func (eNode *NodeExtern) loadInternalNode(n *node, recursive, sorted bool) {
 		eNode.Value = &value
 	}
 
-	eNode.Expiration, eNode.TTL = n.ExpirationAndTTL()
+	eNode.Expiration, eNode.TTL = n.expirationAndTTL(clock)
 }
 
 type NodeExterns []*NodeExtern

store/stats_test.go

@@ -87,15 +87,12 @@ func TestStoreStatsDeleteFail(t *testing.T) {
 //Ensure that the number of expirations is recorded in the stats.
 func TestStoreStatsExpireCount(t *testing.T) {
 	s := newStore()
+	fc := newFakeClock()
+	s.clock = fc
 
-	c := make(chan bool)
-	defer func() {
-		c <- true
-	}()
-
-	go mockSyncService(s.DeleteExpiredKeys, c)
-	s.Create("/foo", false, "bar", false, time.Now().Add(500*time.Millisecond))
+	s.Create("/foo", false, "bar", false, fc.Now().Add(500*time.Millisecond))
 	assert.Equal(t, uint64(0), s.Stats.ExpireCount, "")
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 	assert.Equal(t, uint64(1), s.Stats.ExpireCount, "")
 }

store/store.go

@@ -25,6 +25,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	etcdErr "github.com/coreos/etcd/error"
 )
 
@@ -68,10 +69,13 @@ type store struct {
 	CurrentVersion int
 	ttlKeyHeap     *ttlKeyHeap  // need to recovery manually
 	worldLock      sync.RWMutex // stop the world lock
+	clock          clockwork.Clock
 }
 
 func New() Store {
-	return newStore()
+	s := newStore()
+	s.clock = clockwork.NewRealClock()
+	return s
 }
 
 func newStore() *store {
@@ -114,7 +118,7 @@ func (s *store) Get(nodePath string, recursive, sorted bool) (*Event, error) {
 
 	e := newEvent(Get, nodePath, n.ModifiedIndex, n.CreatedIndex)
 	e.EtcdIndex = s.CurrentIndex
-	e.Node.loadInternalNode(n, recursive, sorted)
+	e.Node.loadInternalNode(n, recursive, sorted, s.clock)
 
 	s.Stats.Inc(GetSuccess)
 
@@ -172,7 +176,7 @@ func (s *store) Set(nodePath string, dir bool, value string, expireTime time.Tim
 	// Put prevNode into event
 	if getErr == nil {
 		prev := newEvent(Get, nodePath, n.ModifiedIndex, n.CreatedIndex)
-		prev.Node.loadInternalNode(n, false, false)
+		prev.Node.loadInternalNode(n, false, false, s.clock)
 		e.PrevNode = prev.Node
 	}
 
@@ -230,7 +234,7 @@ func (s *store) CompareAndSwap(nodePath string, prevValue string, prevIndex uint
 
 	e := newEvent(CompareAndSwap, nodePath, s.CurrentIndex, n.CreatedIndex)
 	e.EtcdIndex = s.CurrentIndex
-	e.PrevNode = n.Repr(false, false)
+	e.PrevNode = n.Repr(false, false, s.clock)
 	eNode := e.Node
 
 	// if test succeed, write the value
@@ -240,7 +244,7 @@ func (s *store) CompareAndSwap(nodePath string, prevValue string, prevIndex uint
 	// copy the value for safety
 	valueCopy := value
 	eNode.Value = &valueCopy
-	eNode.Expiration, eNode.TTL = n.ExpirationAndTTL()
+	eNode.Expiration, eNode.TTL = n.expirationAndTTL(s.clock)
 
 	s.WatcherHub.notify(e)
 	s.Stats.Inc(CompareAndSwapSuccess)
@@ -275,7 +279,7 @@ func (s *store) Delete(nodePath string, dir, recursive bool) (*Event, error) {
 	nextIndex := s.CurrentIndex + 1
 	e := newEvent(Delete, nodePath, nextIndex, n.CreatedIndex)
 	e.EtcdIndex = nextIndex
-	e.PrevNode = n.Repr(false, false)
+	e.PrevNode = n.Repr(false, false, s.clock)
 	eNode := e.Node
 
 	if n.IsDir() {
@@ -335,7 +339,7 @@ func (s *store) CompareAndDelete(nodePath string, prevValue string, prevIndex ui
 
 	e := newEvent(CompareAndDelete, nodePath, s.CurrentIndex, n.CreatedIndex)
 	e.EtcdIndex = s.CurrentIndex
-	e.PrevNode = n.Repr(false, false)
+	e.PrevNode = n.Repr(false, false, s.clock)
 
 	callback := func(path string) { // notify function
 		// notify the watchers with deleted set true
@@ -414,7 +418,7 @@ func (s *store) Update(nodePath string, newValue string, expireTime time.Time) (
 
 	e := newEvent(Update, nodePath, nextIndex, n.CreatedIndex)
 	e.EtcdIndex = nextIndex
-	e.PrevNode = n.Repr(false, false)
+	e.PrevNode = n.Repr(false, false, s.clock)
 	eNode := e.Node
 
 	if n.IsDir() && len(newValue) != 0 {
@@ -436,7 +440,7 @@ func (s *store) Update(nodePath string, newValue string, expireTime time.Time) (
 	// update ttl
 	n.UpdateTTL(expireTime)
 
-	eNode.Expiration, eNode.TTL = n.ExpirationAndTTL()
+	eNode.Expiration, eNode.TTL = n.expirationAndTTL(s.clock)
 
 	s.WatcherHub.notify(e)
 
@@ -463,8 +467,8 @@ func (s *store) internalCreate(nodePath string, dir bool, value string, unique,
 		return nil, etcdErr.NewError(etcdErr.EcodeRootROnly, "/", currIndex)
 	}
 
-	// Assume expire times that are way in the past are not valid.
-	// This can occur when the time is serialized to JSON and read back in.
+	// Assume expire times that are way in the past are
+	// This can occur when the time is serialized to JS
 	if expireTime.Before(minExpireTime) {
 		expireTime = Permanent
 	}
@@ -491,7 +495,7 @@ func (s *store) internalCreate(nodePath string, dir bool, value string, unique,
 			if n.IsDir() {
 				return nil, etcdErr.NewError(etcdErr.EcodeNotFile, nodePath, currIndex)
 			}
-			e.PrevNode = n.Repr(false, false)
+			e.PrevNode = n.Repr(false, false, s.clock)
 
 			n.Remove(false, false, nil)
 		} else {
@@ -519,7 +523,7 @@ func (s *store) internalCreate(nodePath string, dir bool, value string, unique,
 	if !n.IsPermanent() {
 		s.ttlKeyHeap.push(n)
 
-		eNode.Expiration, eNode.TTL = n.ExpirationAndTTL()
+		eNode.Expiration, eNode.TTL = n.expirationAndTTL(s.clock)
 	}
 
 	s.CurrentIndex = nextIndex
@@ -568,7 +572,7 @@ func (s *store) DeleteExpiredKeys(cutoff time.Time) {
 		s.CurrentIndex++
 		e := newEvent(Expire, node.Path, s.CurrentIndex, node.CreatedIndex)
 		e.EtcdIndex = s.CurrentIndex
-		e.PrevNode = node.Repr(false, false)
+		e.PrevNode = node.Repr(false, false, s.clock)
 
 		callback := func(path string) { // notify function
 			// notify the watchers with deleted set true

store/store_test.go

@@ -20,6 +20,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
 	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/stretchr/testify/assert"
 	etcdErr "github.com/coreos/etcd/error"
 )
@@ -37,17 +38,39 @@ func TestStoreGetValue(t *testing.T) {
 	assert.Equal(t, *e.Node.Value, "bar", "")
 }
 
+// Ensure that any TTL <= minExpireTime becomes Permanent
+func TestMinExpireTime(t *testing.T) {
+	s := newStore()
+	fc := clockwork.NewFakeClock()
+	s.clock = fc
+	// FakeClock starts at 0, so minExpireTime should be far in the future.. but just in case
+	assert.True(t, minExpireTime.After(fc.Now()), "minExpireTime should be ahead of FakeClock!")
+	s.Create("/foo", false, "Y", false, fc.Now().Add(3*time.Second))
+	fc.Advance(5 * time.Second)
+	// Ensure it hasn't expired
+	s.DeleteExpiredKeys(fc.Now())
+	var eidx uint64 = 1
+	e, err := s.Get("/foo", true, false)
+	assert.Nil(t, err, "")
+	assert.Equal(t, e.EtcdIndex, eidx, "")
+	assert.Equal(t, e.Action, "get", "")
+	assert.Equal(t, e.Node.Key, "/foo", "")
+	assert.Equal(t, e.Node.TTL, 0)
+}
+
 // Ensure that the store can recrusively retrieve a directory listing.
 // Note that hidden files should not be returned.
 func TestStoreGetDirectory(t *testing.T) {
 	s := newStore()
+	fc := newFakeClock()
+	s.clock = fc
 	s.Create("/foo", true, "", false, Permanent)
 	s.Create("/foo/bar", false, "X", false, Permanent)
 	s.Create("/foo/_hidden", false, "*", false, Permanent)
 	s.Create("/foo/baz", true, "", false, Permanent)
 	s.Create("/foo/baz/bat", false, "Y", false, Permanent)
 	s.Create("/foo/baz/_hidden", false, "*", false, Permanent)
-	s.Create("/foo/baz/ttl", false, "Y", false, time.Now().Add(time.Second*3))
+	s.Create("/foo/baz/ttl", false, "Y", false, fc.Now().Add(time.Second*3))
 	var eidx uint64 = 7
 	e, err := s.Get("/foo", true, false)
 	assert.Nil(t, err, "")
@@ -311,21 +334,17 @@ func TestStoreUpdateFailsIfDirectory(t *testing.T) {
 // Ensure that the store can update the TTL on a value.
 func TestStoreUpdateValueTTL(t *testing.T) {
 	s := newStore()
-
-	c := make(chan bool)
-	defer func() {
-		c <- true
-	}()
-	go mockSyncService(s.DeleteExpiredKeys, c)
+	fc := newFakeClock()
+	s.clock = fc
 
 	var eidx uint64 = 2
 	s.Create("/foo", false, "bar", false, Permanent)
-	_, err := s.Update("/foo", "baz", time.Now().Add(500*time.Millisecond))
+	_, err := s.Update("/foo", "baz", fc.Now().Add(500*time.Millisecond))
 	e, _ := s.Get("/foo", false, false)
 	assert.Equal(t, *e.Node.Value, "baz", "")
 	assert.Equal(t, e.EtcdIndex, eidx, "")
-
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 	e, err = s.Get("/foo", false, false)
 	assert.Nil(t, e, "")
 	assert.Equal(t, err.(*etcdErr.Error).ErrorCode, etcdErr.EcodeKeyNotFound, "")
@@ -334,24 +353,21 @@ func TestStoreUpdateValueTTL(t *testing.T) {
 // Ensure that the store can update the TTL on a directory.
 func TestStoreUpdateDirTTL(t *testing.T) {
 	s := newStore()
-
-	c := make(chan bool)
-	defer func() {
-		c <- true
-	}()
-	go mockSyncService(s.DeleteExpiredKeys, c)
+	fc := newFakeClock()
+	s.clock = fc
 
 	var eidx uint64 = 3
 	s.Create("/foo", true, "", false, Permanent)
 	s.Create("/foo/bar", false, "baz", false, Permanent)
-	e, err := s.Update("/foo", "", time.Now().Add(500*time.Millisecond))
+	e, err := s.Update("/foo", "", fc.Now().Add(500*time.Millisecond))
 	assert.Equal(t, e.Node.Dir, true, "")
 	assert.Equal(t, e.EtcdIndex, eidx, "")
 	e, _ = s.Get("/foo/bar", false, false)
 	assert.Equal(t, *e.Node.Value, "baz", "")
 	assert.Equal(t, e.EtcdIndex, eidx, "")
 
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 	e, err = s.Get("/foo/bar", false, false)
 	assert.Nil(t, e, "")
 	assert.Equal(t, err.(*etcdErr.Error).ErrorCode, etcdErr.EcodeKeyNotFound, "")
@@ -707,23 +723,20 @@ func TestStoreWatchRecursiveCompareAndSwap(t *testing.T) {
 // Ensure that the store can watch for key expiration.
 func TestStoreWatchExpire(t *testing.T) {
 	s := newStore()
-
-	stopChan := make(chan bool)
-	defer func() {
-		stopChan <- true
-	}()
-	go mockSyncService(s.DeleteExpiredKeys, stopChan)
+	fc := newFakeClock()
+	s.clock = fc
 
 	var eidx uint64 = 2
-	s.Create("/foo", false, "bar", false, time.Now().Add(500*time.Millisecond))
-	s.Create("/foofoo", false, "barbarbar", false, time.Now().Add(500*time.Millisecond))
+	s.Create("/foo", false, "bar", false, fc.Now().Add(500*time.Millisecond))
+	s.Create("/foofoo", false, "barbarbar", false, fc.Now().Add(500*time.Millisecond))
 
 	w, _ := s.Watch("/", true, false, 0)
 	assert.Equal(t, w.StartIndex(), eidx, "")
 	c := w.EventChan()
 	e := nbselect(c)
 	assert.Nil(t, e, "")
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 	eidx = 3
 	e = nbselect(c)
 	assert.Equal(t, e.EtcdIndex, eidx, "")
@@ -790,32 +803,25 @@ func TestStoreRecover(t *testing.T) {
 // Ensure that the store can recover from a previously saved state that includes an expiring key.
 func TestStoreRecoverWithExpiration(t *testing.T) {
 	s := newStore()
+	s.clock = newFakeClock()
 
-	c := make(chan bool)
-	defer func() {
-		c <- true
-	}()
-	go mockSyncService(s.DeleteExpiredKeys, c)
+	fc := newFakeClock()
 
 	var eidx uint64 = 4
 	s.Create("/foo", true, "", false, Permanent)
 	s.Create("/foo/x", false, "bar", false, Permanent)
-	s.Create("/foo/y", false, "baz", false, time.Now().Add(5*time.Millisecond))
+	s.Create("/foo/y", false, "baz", false, fc.Now().Add(5*time.Millisecond))
 	b, err := s.Save()
 
 	time.Sleep(10 * time.Millisecond)
 
 	s2 := newStore()
-
-	c2 := make(chan bool)
-	defer func() {
-		c2 <- true
-	}()
-	go mockSyncService(s2.DeleteExpiredKeys, c2)
+	s2.clock = fc
 
 	s2.Recovery(b)
 
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 
 	e, err := s.Get("/foo/x", false, false)
 	assert.Nil(t, err, "")
@@ -908,24 +914,22 @@ func TestStoreWatchRecursiveDeleteWithHiddenKey(t *testing.T) {
 // Ensure that the store doesn't see expirations of hidden keys.
 func TestStoreWatchExpireWithHiddenKey(t *testing.T) {
 	s := newStore()
+	fc := newFakeClock()
+	s.clock = fc
 
-	stopChan := make(chan bool)
-	defer func() {
-		stopChan <- true
-	}()
-	go mockSyncService(s.DeleteExpiredKeys, stopChan)
-
-	s.Create("/_foo", false, "bar", false, time.Now().Add(500*time.Millisecond))
-	s.Create("/foofoo", false, "barbarbar", false, time.Now().Add(1000*time.Millisecond))
+	s.Create("/_foo", false, "bar", false, fc.Now().Add(500*time.Millisecond))
+	s.Create("/foofoo", false, "barbarbar", false, fc.Now().Add(1000*time.Millisecond))
 
 	w, _ := s.Watch("/", true, false, 0)
 	c := w.EventChan()
 	e := nbselect(c)
 	assert.Nil(t, e, "")
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 	e = nbselect(c)
 	assert.Nil(t, e, "")
-	time.Sleep(600 * time.Millisecond)
+	fc.Advance(600 * time.Millisecond)
+	s.DeleteExpiredKeys(fc.Now())
 	e = nbselect(c)
 	assert.Equal(t, e.Action, "expire", "")
 	assert.Equal(t, e.Node.Key, "/foofoo", "")
@@ -970,14 +974,11 @@ func nbselect(c <-chan *Event) *Event {
 	}
 }
 
-func mockSyncService(f func(now time.Time), c chan bool) {
-	ticker := time.Tick(time.Millisecond * 500)
-	for {
-		select {
-		case <-c:
-			return
-		case now := <-ticker:
-			f(now)
-		}
+// newFakeClock creates a new FakeClock that has been advanced to at least minExpireTime
+func newFakeClock() clockwork.FakeClock {
+	fc := clockwork.NewFakeClock()
+	for minExpireTime.After(fc.Now()) {
+		fc.Advance((0x1 << 62) * time.Nanosecond)
 	}
+	return fc
 }