only run one instance 'cron.run()'

[winxxp]

If call twice

func (c *Cron) Start() {
    c.running = true
    go c.run()
}

[elgs]

So is this a question or a statement?

[winxxp]

I mean Start() method shoud be a singleton method, to protected call Start() many times, or appliction must be protected self.

[elgs]

@winxxp thanks. That makes sense. Probably the Start should be like this:

func (c *Cron) Start() {
    if c.running {
        return
    }
    c.running = true
    go c.run()
}

[winxxp]

thread-safe better.

[dmitshur]

Is there a good reason your application can't call Start once?

Or are you saying, in case a poorly behaved application calls Start more than once, then cron should handle that situation better?

[winxxp]

I used zookeeper to elect master, when network broken or other slave online, all node recvived new nodes to elect new leader, if leader call start, or stop, sometime the elected reslt is the leader node also leader node, so it call twice or more.

Now I protected it out Start/Stop self.