ctxlock

Documentation

Overview

Package ctxlock provides a locking mechanism based on context cancellation.

Contexts derived from a Locker are canceled when the underlying connection to the lock provider is gone, or when a parent context is canceled.

This package makes use of "unsafe" to avoid some allocations, but the "safe" build tag can be provided to use allocating versions of the functions.

Index

• type Locker
  • func New(ctx context.Context, p *pgxpool.Pool) (*Locker, error)
  • func (l *Locker) Close(_ context.Context) (_ error)
  • func (l *Locker) Lock(parent context.Context, key string) (context.Context, context.CancelFunc)
  • func (l *Locker) TryLock(parent context.Context, key string) (context.Context, context.CancelFunc)

Types

type Locker

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

Locker provides context-scoped locks.

func New

func New(ctx context.Context, p *pgxpool.Pool) (*Locker, error)

New creates a Locker that will pull connections from the provided pool.

The provided context is only used for logging and initial setup. Close must be called to release held resources.

func (*Locker) Close

func (l *Locker) Close(_ context.Context) (_ error)

Close spins down background goroutines and frees resources.

func (*Locker) Lock

func (l *Locker) Lock(parent context.Context, key string) (context.Context, context.CancelFunc)

Lock attempts to obtain the named lock until it succeeds or the passed Context is cancelled.

func (*Locker) TryLock

func (l *Locker) TryLock(parent context.Context, key string) (context.Context, context.CancelFunc)

TryLock attempts to lock on the provided key.

If unsuccessful, an already-cancelled Context will be returned.

If successful, the returned Context will be parented to the passed-in Context and also to the underlying connection used for the lock.