type MemoryJobNotifier struct {
    conds map[string] *sync.Cond
    lock sync.Mutex
}

func (jn MemoryJobNotifier) Wait(name string) error {
    jn.getCond(name).Wait()
    return nil
}

func (jn MemoryJobNotifier) getCond(name string) *sync.Cond {
    jn.lock.Lock()
    defer jn.lock.Unlock()
    cond, ok := jn.conds[name]
    if !ok {
        cond = sync.NewCond(&sync.Mutex{})
        jn.conds[name] = cond
    }
    return cond
}

func (jn MemoryJobNotifier) Broadcast(name string) error {
    jn.lock.Lock()
    defer jn.lock.Lock()
    cond, ok := jn.conds[name]
    if !ok {
        return nil
    }
    cond.Broadcast()
    delete(jn.conds, name)
    return nil
}