Documentation
¶
Overview ¶
Package concurrency implements concurrency operations on top of etcd such as distributed locks, barriers, and elections.
Index ¶
- Variables
- func NewLocker(s *Session, pfx string) sync.Locker
- func NewSTMReadCommitted(ctx context.Context, c *v3.Client, apply func(STM) error) (*v3.TxnResponse, error)
- 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)
- type Election
- func (e *Election) Campaign(ctx context.Context, val string) error
- func (e *Election) Key() string
- func (e *Election) Leader(ctx context.Context) (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(ctx context.Context) (err error)
- type Mutex
- type STM
- type Session
- type SessionOption
Constants ¶
This section is empty.
Variables ¶
var ( ErrElectionNotLeader = errors.New("election: not leader") ErrElectionNoLeader = errors.New("election: no leader") )
Functions ¶
func NewSTMReadCommitted ¶
func NewSTMReadCommitted(ctx context.Context, c *v3.Client, apply func(STM) error) (*v3.TxnResponse, error)
NewSTMReadCommitted initiates a new read committed transaction.
Types ¶
type Election ¶
type Election struct {
// contains filtered or unexported fields
}
func NewElection ¶
NewElection returns a new election on a given key prefix.
func (*Election) Campaign ¶
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) 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.
type Mutex ¶
type Mutex struct {
// contains filtered or unexported fields
}
Mutex implements the sync Locker interface with etcd
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, opts ...SessionOption) (*Session, error)
NewSession gets the leased session for a client.
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.
type SessionOption ¶
type SessionOption func(*sessionOptions)
SessionOption configures Session.
func WithContext ¶
func WithContext(ctx context.Context) SessionOption
WithContext assigns a context to the session instead of defaulting to using the client context. This is useful for canceling NewSession and Close operations immediately without having to close the client. If the context is canceled before Close() completes, the session's lease will be abandoned and left to expire instead of being revoked.
func WithTTL ¶
func WithTTL(ttl int) SessionOption
WithTTL configures the session's TTL in seconds. If TTL is <= 0, the default 60 seconds TTL will be used.
Source Files