func (me *AmqpConnection) Channel() (ch *AmqpChannel, err error) {
ok := true
select {
case ch, ok = <-me.channels:
break
default:
// with this,
// we can skip checking of mutex.
if me.noMore {
ch, ok = <-me.channels
break
}
me.cLock.Lock()
defer me.cLock.Unlock()
if me.cntChannels < me.maxChannel && !me.noMore {
var c *amqp.Channel
c, err = me.conn.Channel()
// enable publisher confirm
err = c.Confirm(false)
if err != nil {
break
}
ch = &AmqpChannel{
Channel: c,
Confirm: c.NotifyPublish(make(chan amqp.Confirmation, 1)),
Cancel: c.NotifyCancel(make(chan string, 1)),
}
me.cntChannels++
} else {
me.noMore = true
ch, ok = <-me.channels
break
}
}
if !ok {
err = errors.New("channel pool is closed")
}
return
}