package concurrency

import "github.com/coreos/etcd/clientv3/concurrency"

Copyright 2016 CoreOS, Inc.

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.

Copyright 2016 CoreOS, Inc.

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.

Index ¶

• Variables
• func NewLocker(client *v3.Client, pfx string) sync.Locker
• func NewSTMRepeatable(ctx context.Context, c *v3.Client, apply func(STM) error) (*v3.TxnResponse, error)
• func NewSTMSerializable(ctx context.Context, c *v3.Client, apply func(STM) error) (*v3.TxnResponse, error)
• func NewUniqueKV(ctx context.Context, kv v3.KV, pfx, val string, opts ...v3.OpOption) (string, int64, error)
• func NewUniqueKey(ctx context.Context, kv v3.KV, pfx string, opts ...v3.OpOption) (string, int64, error)
• type Election
• func NewElection(client *v3.Client, pfx string) *Election
• func (e *Election) Campaign(ctx context.Context, val string) error
• func (e *Election) Key() string
• func (e *Election) Leader() (string, error)
• func (e *Election) Observe(ctx context.Context) <-chan v3.GetResponse
• func (e *Election) Proclaim(ctx context.Context, val string) error
• func (e *Election) Resign() (err error)
• type Mutex
• func NewMutex(client *v3.Client, pfx string) *Mutex
• func (m *Mutex) IsOwner() v3.Cmp
• func (m *Mutex) Key() string
• func (m *Mutex) Lock(ctx context.Context) error
• func (m *Mutex) Unlock() error
• type STM
• type Session
• func NewSession(client *v3.Client) (*Session, error)
• func (s *Session) Close() error
• func (s *Session) Done() <-chan struct{}
• func (s *Session) Lease() v3.LeaseID
• func (s *Session) Orphan()

Variables ¶

var (
	ErrElectionNotLeader = errors.New("election: not leader")
	ErrElectionNoLeader  = errors.New("election: no leader")
)

Functions ¶

func NewLocker ¶

func NewLocker(client *v3.Client, pfx string) sync.Locker

NewLocker creates a sync.Locker backed by an etcd mutex.

func NewSTMRepeatable ¶

func NewSTMRepeatable(ctx context.Context, c *v3.Client, apply func(STM) error) (*v3.TxnResponse, error)

NewSTMRepeatable initiates new repeatable read transaction; reads within the same transaction attempt always return the same data.

func NewSTMSerializable ¶

func NewSTMSerializable(ctx context.Context, c *v3.Client, apply func(STM) error) (*v3.TxnResponse, error)

NewSTMSerializable initiates a new serialized transaction; reads within the same transactiona attempt return data from the revision of the first read.

func NewUniqueKV ¶

func NewUniqueKV(ctx context.Context, kv v3.KV, pfx, val string, opts ...v3.OpOption) (string, int64, error)

func NewUniqueKey ¶

func NewUniqueKey(ctx context.Context, kv v3.KV, pfx string, opts ...v3.OpOption) (string, int64, error)

NewUniqueKey creates a new key from a given prefix.

Types ¶

type Election ¶

type Election struct {
	// contains filtered or unexported fields
}

func NewElection ¶

func NewElection(client *v3.Client, pfx string) *Election

NewElection returns a new election on a given key prefix.

func (*Election) Campaign ¶

func (e *Election) Campaign(ctx context.Context, val string) error

Campaign puts a value as eligible for the election. It blocks until it is elected, an error occurs, or the context is cancelled.

func (*Election) Key ¶

func (e *Election) Key() string

Key returns the leader key if elected, empty string otherwise.

func (*Election) Leader ¶

func (e *Election) Leader() (string, error)

Leader returns the leader value for the current election.

func (*Election) Observe ¶

func (e *Election) Observe(ctx context.Context) <-chan v3.GetResponse

Observe returns a channel that observes all leader proposal values as GetResponse values on the current leader key. The channel closes when the context is cancelled or the underlying watcher is otherwise disrupted.

func (*Election) Proclaim ¶

func (e *Election) Proclaim(ctx context.Context, val string) error

Proclaim lets the leader announce a new value without another election.

func (*Election) Resign ¶

func (e *Election) Resign() (err error)

Resign lets a leader start a new election.

type Mutex ¶

type Mutex struct {
	// contains filtered or unexported fields
}

Mutex implements the sync Locker interface with etcd

func NewMutex ¶

func NewMutex(client *v3.Client, pfx string) *Mutex

func (*Mutex) IsOwner ¶

func (m *Mutex) IsOwner() v3.Cmp

func (*Mutex) Key ¶

func (m *Mutex) Key() string

func (*Mutex) Lock ¶

func (m *Mutex) Lock(ctx context.Context) error

Lock locks the mutex with a cancellable context. If the context is cancelled while trying to acquire the lock, the mutex tries to clean its stale lock entry.

func (*Mutex) Unlock ¶

func (m *Mutex) Unlock() error

type STM ¶

type STM interface {
	// Get returns the value for a key and inserts the key in the txn's read set.
	// If Get fails, it aborts the transaction with an error, never returning.
	Get(key string) string
	// Put adds a value for a key to the write set.
	Put(key, val string, opts ...v3.OpOption)
	// Rev returns the revision of a key in the read set.
	Rev(key string) int64
	// Del deletes a key.
	Del(key string)
	// contains filtered or unexported methods
}

STM is an interface for software transactional memory.

type Session ¶

type Session struct {
	// contains filtered or unexported fields
}

Session represents a lease kept alive for the lifetime of a client. Fault-tolerant applications may use sessions to reason about liveness.

func NewSession ¶

func NewSession(client *v3.Client) (*Session, error)

NewSession gets the leased session for a client.

func (*Session) Close ¶

func (s *Session) Close() error

Close orphans the session and revokes the session lease.

func (*Session) Done ¶

func (s *Session) Done() <-chan struct{}

Done returns a channel that closes when the lease is orphaned, expires, or is otherwise no longer being refreshed.

func (*Session) Lease ¶

func (s *Session) Lease() v3.LeaseID

Lease is the lease ID for keys bound to the session.

func (*Session) Orphan ¶

func (s *Session) Orphan()

Orphan ends the refresh for the session lease. This is useful in case the state of the client connection is indeterminate (revoke would fail) or when transferring lease ownership.

Source Files ¶

election.go key.go mutex.go session.go stm.go