type RWLocker interface {
	GetLock(ctx context.Context, timeout *dynamicTimeout) (lkCtx LockContext, timedOutErr error)
	Unlock(lkCtx LockContext)
	GetRLock(ctx context.Context, timeout *dynamicTimeout) (lkCtx LockContext, timedOutErr error)
	RUnlock(lkCtx LockContext)
}

// LockContext lock context holds the lock backed context and canceler for the context.
type LockContext struct {
	ctx    context.Context
	cancel context.CancelFunc
}

}

func (ld sharedLock) GetLock(ctx context.Context) (context.Context, context.CancelFunc) {
	l := <-ld.lockContext
	return mergeContext(l.Context(), ctx)
}

func newSharedLock(ctx context.Context, objAPI ObjectLayer, lockName string) *sharedLock {
	l := &sharedLock{
		lockContext: make(chan LockContext),
	}
	go l.backgroundRoutine(ctx, objAPI, lockName)

	return l