Merge pull request #16053 from saad-ali/attachDetachMutextFix

Fix GCE Cloud/Attach/Detach stability issues
This commit is contained in:
Daniel Smith
2015-10-26 13:05:27 -07:00
6 changed files with 267 additions and 355 deletions

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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
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 keymutex
import (
"fmt"
"github.com/golang/glog"
"sync"
)
// KeyMutex is a thread-safe interface for aquiring locks on arbitrary strings.
type KeyMutex interface {
// Aquires a lock associated with the specified ID, creates the lock if one doesn't already exist.
LockKey(id string)
// Releases the lock associated with the specified ID.
// Returns an error if the specified ID doesn't exist.
UnlockKey(id string) error
}
// Returns a new instance of a key mutex.
func NewKeyMutex() KeyMutex {
return &keyMutex{
mutexMap: make(map[string]*sync.Mutex),
}
}
type keyMutex struct {
sync.RWMutex
mutexMap map[string]*sync.Mutex
}
// Aquires a lock associated with the specified ID (creates the lock if one doesn't already exist).
func (km *keyMutex) LockKey(id string) {
glog.V(5).Infof("LockKey(...) called for id %q\r\n", id)
mutex := km.getOrCreateLock(id)
mutex.Lock()
glog.V(5).Infof("LockKey(...) for id %q completed.\r\n", id)
}
// Releases the lock associated with the specified ID.
// Returns an error if the specified ID doesn't exist.
func (km *keyMutex) UnlockKey(id string) error {
glog.V(5).Infof("UnlockKey(...) called for id %q\r\n", id)
km.RLock()
defer km.RUnlock()
mutex, exists := km.mutexMap[id]
if !exists {
return fmt.Errorf("id %q not found", id)
}
glog.V(5).Infof("UnlockKey(...) for id. Mutex found, trying to unlock it. %q\r\n", id)
mutex.Unlock()
glog.V(5).Infof("UnlockKey(...) for id %q completed.\r\n", id)
return nil
}
// Returns lock associated with the specified ID, or creates the lock if one doesn't already exist.
func (km *keyMutex) getOrCreateLock(id string) *sync.Mutex {
km.Lock()
defer km.Unlock()
if _, exists := km.mutexMap[id]; !exists {
km.mutexMap[id] = &sync.Mutex{}
}
return km.mutexMap[id]
}

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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
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 keymutex
import (
"testing"
"time"
)
const (
callbackTimeout = 1 * time.Second
)
func Test_SingleLock_NoUnlock(t *testing.T) {
// Arrange
km := NewKeyMutex()
key := "fakeid"
callbackCh := make(chan interface{})
// Act
go lockAndCallback(km, key, callbackCh)
// Assert
verifyCallbackHappens(t, callbackCh)
}
func Test_SingleLock_SingleUnlock(t *testing.T) {
// Arrange
km := NewKeyMutex()
key := "fakeid"
callbackCh := make(chan interface{})
// Act & Assert
go lockAndCallback(km, key, callbackCh)
verifyCallbackHappens(t, callbackCh)
km.UnlockKey(key)
}
func Test_DoubleLock_DoubleUnlock(t *testing.T) {
// Arrange
km := NewKeyMutex()
key := "fakeid"
callbackCh1stLock := make(chan interface{})
callbackCh2ndLock := make(chan interface{})
// Act & Assert
go lockAndCallback(km, key, callbackCh1stLock)
verifyCallbackHappens(t, callbackCh1stLock)
go lockAndCallback(km, key, callbackCh2ndLock)
verifyCallbackDoesntHappens(t, callbackCh2ndLock)
km.UnlockKey(key)
verifyCallbackHappens(t, callbackCh2ndLock)
km.UnlockKey(key)
}
func lockAndCallback(km KeyMutex, id string, callbackCh chan<- interface{}) {
km.LockKey(id)
callbackCh <- true
}
func verifyCallbackHappens(t *testing.T, callbackCh <-chan interface{}) bool {
select {
case <-callbackCh:
return true
case <-time.After(callbackTimeout):
t.Fatalf("Timed out waiting for callback.")
return false
}
}
func verifyCallbackDoesntHappens(t *testing.T, callbackCh <-chan interface{}) bool {
select {
case <-callbackCh:
t.Fatalf("Unexpected callback.")
return false
case <-time.After(callbackTimeout):
return true
}
}
func verifyNoError(t *testing.T, err error, name string) {
if err != nil {
t.Fatalf("Unexpected response on %q. Expected: <no error> Actual: <%v>", name, err)
}
}
func verifyError(t *testing.T, err error, name string) {
if err == nil {
t.Fatalf("Unexpected response on %q. Expected: <error> Actual: <no error>", name)
}
}
func verifyMsg(t *testing.T, expected, actual string) {
if actual != expected {
t.Fatalf("Unexpected testMsg value. Expected: <%v> Actual: <%v>", expected, actual)
}
}

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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
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 operationmanager
import (
"fmt"
"sync"
)
// Operation Manager is a thread-safe interface for keeping track of multiple pending async operations.
type OperationManager interface {
// Called when the operation with the given ID has started.
// Creates a new channel with specified buffer size tracked with the specified ID.
// Returns a read-only version of the newly created channel.
// Returns an error if an entry with the specified ID already exists (previous entry must be removed by calling Close).
Start(id string, bufferSize uint) (<-chan interface{}, error)
// Called when the operation with the given ID has terminated.
// Closes and removes the channel associated with ID.
// Returns an error if no associated channel exists.
Close(id string) error
// Attempts to send msg to the channel associated with ID.
// Returns an error if no associated channel exists.
Send(id string, msg interface{}) error
// Returns true if an entry with the specified ID already exists.
Exists(id string) bool
}
// Returns a new instance of a channel manager.
func NewOperationManager() OperationManager {
return &operationManager{
chanMap: make(map[string]chan interface{}),
}
}
type operationManager struct {
sync.RWMutex
chanMap map[string]chan interface{}
}
// Called when the operation with the given ID has started.
// Creates a new channel with specified buffer size tracked with the specified ID.
// Returns a read-only version of the newly created channel.
// Returns an error if an entry with the specified ID already exists (previous entry must be removed by calling Close).
func (cm *operationManager) Start(id string, bufferSize uint) (<-chan interface{}, error) {
cm.Lock()
defer cm.Unlock()
if _, exists := cm.chanMap[id]; exists {
return nil, fmt.Errorf("id %q already exists", id)
}
cm.chanMap[id] = make(chan interface{}, bufferSize)
return cm.chanMap[id], nil
}
// Called when the operation with the given ID has terminated.
// Closes and removes the channel associated with ID.
// Returns an error if no associated channel exists.
func (cm *operationManager) Close(id string) error {
cm.Lock()
defer cm.Unlock()
if _, exists := cm.chanMap[id]; !exists {
return fmt.Errorf("id %q not found", id)
}
close(cm.chanMap[id])
delete(cm.chanMap, id)
return nil
}
// Attempts to send msg to the channel associated with ID.
// Returns an error if no associated channel exists.
func (cm *operationManager) Send(id string, msg interface{}) error {
cm.RLock()
defer cm.RUnlock()
if _, exists := cm.chanMap[id]; !exists {
return fmt.Errorf("id %q not found", id)
}
cm.chanMap[id] <- msg
return nil
}
// Returns true if an entry with the specified ID already exists.
func (cm *operationManager) Exists(id string) (exists bool) {
cm.RLock()
defer cm.RUnlock()
_, exists = cm.chanMap[id]
return
}

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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
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.
*/
// Channel Manager keeps track of multiple channels
package operationmanager
import (
"testing"
)
func TestStart(t *testing.T) {
// Arrange
cm := NewOperationManager()
chanId := "testChanId"
testMsg := "test message"
// Act
ch, startErr := cm.Start(chanId, 1 /* bufferSize */)
sigErr := cm.Send(chanId, testMsg)
// Assert
verifyNoError(t, startErr, "Start")
verifyNoError(t, sigErr, "Send")
actualMsg := <-ch
verifyMsg(t, testMsg /* expected */, actualMsg.(string) /* actual */)
}
func TestStartIdExists(t *testing.T) {
// Arrange
cm := NewOperationManager()
chanId := "testChanId"
// Act
_, startErr1 := cm.Start(chanId, 1 /* bufferSize */)
_, startErr2 := cm.Start(chanId, 1 /* bufferSize */)
// Assert
verifyNoError(t, startErr1, "Start1")
verifyError(t, startErr2, "Start2")
}
func TestStartAndAdd2Chans(t *testing.T) {
// Arrange
cm := NewOperationManager()
chanId1 := "testChanId1"
chanId2 := "testChanId2"
testMsg1 := "test message 1"
testMsg2 := "test message 2"
// Act
ch1, startErr1 := cm.Start(chanId1, 1 /* bufferSize */)
ch2, startErr2 := cm.Start(chanId2, 1 /* bufferSize */)
sigErr1 := cm.Send(chanId1, testMsg1)
sigErr2 := cm.Send(chanId2, testMsg2)
// Assert
verifyNoError(t, startErr1, "Start1")
verifyNoError(t, startErr2, "Start2")
verifyNoError(t, sigErr1, "Send1")
verifyNoError(t, sigErr2, "Send2")
actualMsg1 := <-ch1
actualMsg2 := <-ch2
verifyMsg(t, testMsg1 /* expected */, actualMsg1.(string) /* actual */)
verifyMsg(t, testMsg2 /* expected */, actualMsg2.(string) /* actual */)
}
func TestStartAndAdd2ChansAndClose(t *testing.T) {
// Arrange
cm := NewOperationManager()
chanId1 := "testChanId1"
chanId2 := "testChanId2"
testMsg1 := "test message 1"
testMsg2 := "test message 2"
// Act
ch1, startErr1 := cm.Start(chanId1, 1 /* bufferSize */)
ch2, startErr2 := cm.Start(chanId2, 1 /* bufferSize */)
sigErr1 := cm.Send(chanId1, testMsg1)
sigErr2 := cm.Send(chanId2, testMsg2)
cm.Close(chanId1)
sigErr3 := cm.Send(chanId1, testMsg1)
// Assert
verifyNoError(t, startErr1, "Start1")
verifyNoError(t, startErr2, "Start2")
verifyNoError(t, sigErr1, "Send1")
verifyNoError(t, sigErr2, "Send2")
verifyError(t, sigErr3, "Send3")
actualMsg1 := <-ch1
actualMsg2 := <-ch2
verifyMsg(t, testMsg1 /* expected */, actualMsg1.(string) /* actual */)
verifyMsg(t, testMsg2 /* expected */, actualMsg2.(string) /* actual */)
}
func TestExists(t *testing.T) {
// Arrange
cm := NewOperationManager()
chanId1 := "testChanId1"
chanId2 := "testChanId2"
// Act & Assert
verifyExists(t, cm, chanId1, false /* expected */)
verifyExists(t, cm, chanId2, false /* expected */)
_, startErr1 := cm.Start(chanId1, 1 /* bufferSize */)
verifyNoError(t, startErr1, "Start1")
verifyExists(t, cm, chanId1, true /* expected */)
verifyExists(t, cm, chanId2, false /* expected */)
_, startErr2 := cm.Start(chanId2, 1 /* bufferSize */)
verifyNoError(t, startErr2, "Start2")
verifyExists(t, cm, chanId1, true /* expected */)
verifyExists(t, cm, chanId2, true /* expected */)
cm.Close(chanId1)
verifyExists(t, cm, chanId1, false /* expected */)
verifyExists(t, cm, chanId2, true /* expected */)
cm.Close(chanId2)
verifyExists(t, cm, chanId1, false /* expected */)
verifyExists(t, cm, chanId2, false /* expected */)
}
func verifyExists(t *testing.T, cm OperationManager, id string, expected bool) {
if actual := cm.Exists(id); expected != actual {
t.Fatalf("Unexpected Exists(%q) response. Expected: <%v> Actual: <%v>", id, expected, actual)
}
}
func verifyNoError(t *testing.T, err error, name string) {
if err != nil {
t.Fatalf("Unexpected response on %q. Expected: <no error> Actual: <%v>", name, err)
}
}
func verifyError(t *testing.T, err error, name string) {
if err == nil {
t.Fatalf("Unexpected response on %q. Expected: <error> Actual: <no error>", name)
}
}
func verifyMsg(t *testing.T, expected, actual string) {
if actual != expected {
t.Fatalf("Unexpected testMsg value. Expected: <%v> Actual: <%v>", expected, actual)
}
}