dblock

Documentation

Index

• Variables
• type DBLocker
  • func (dbl *DBLocker) Check() bool
  • func (dbl *DBLocker) Lock(ctx context.Context, getdb func(context.Context) (*sqlx.DB, error)) bool
  • func (dbl *DBLocker) Unlock()

Variables

var (
	TrashSweep         = &DBLocker{key: 10001}
	ContainerLogSweep  = &DBLocker{key: 10002}
	KeepBalanceService = &DBLocker{key: 10003} // keep-balance service in periodic-sweep loop
	KeepBalanceActive  = &DBLocker{key: 10004} // keep-balance sweep in progress (either -once=true or service loop)
	Dispatch           = &DBLocker{key: 10005} // any dispatcher running
	RailsMigrations    = &DBLocker{key: 10006}
)

Types

type DBLocker

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

DBLocker uses pg_advisory_lock to maintain a cluster-wide lock for a long-running task like "do X every N seconds".

func (*DBLocker) Check

func (dbl *DBLocker) Check() bool

Check confirms that the lock is still active (i.e., the session is still alive), and re-acquires if needed. Panics if Lock is not acquired first.

Returns false if the context passed to Lock() is canceled before the lock is confirmed or reacquired.

func (*DBLocker) Lock

func (dbl *DBLocker) Lock(ctx context.Context, getdb func(context.Context) (*sqlx.DB, error)) bool

Lock acquires the advisory lock, waiting/reconnecting if needed.

Returns false if ctx is canceled before the lock is acquired.

func (*DBLocker) Unlock

func (dbl *DBLocker) Unlock()