mirror of https://github.com/status-im/op-geth.git
74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
// Copyright 2016 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package event_test
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"github.com/ethereum/go-ethereum/event"
|
|
)
|
|
|
|
func ExampleFeed_acknowledgedEvents() {
|
|
// This example shows how the return value of Send can be used for request/reply
|
|
// interaction between event consumers and producers.
|
|
var feed event.Feed
|
|
type ackedEvent struct {
|
|
i int
|
|
ack chan<- struct{}
|
|
}
|
|
|
|
// Consumers wait for events on the feed and acknowledge processing.
|
|
done := make(chan struct{})
|
|
defer close(done)
|
|
for i := 0; i < 3; i++ {
|
|
ch := make(chan ackedEvent, 100)
|
|
sub := feed.Subscribe(ch)
|
|
go func() {
|
|
defer sub.Unsubscribe()
|
|
for {
|
|
select {
|
|
case ev := <-ch:
|
|
fmt.Println(ev.i) // "process" the event
|
|
ev.ack <- struct{}{}
|
|
case <-done:
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
}
|
|
|
|
// The producer sends values of type ackedEvent with increasing values of i.
|
|
// It waits for all consumers to acknowledge before sending the next event.
|
|
for i := 0; i < 3; i++ {
|
|
acksignal := make(chan struct{})
|
|
n := feed.Send(ackedEvent{i, acksignal})
|
|
for ack := 0; ack < n; ack++ {
|
|
<-acksignal
|
|
}
|
|
}
|
|
// Output:
|
|
// 0
|
|
// 0
|
|
// 0
|
|
// 1
|
|
// 1
|
|
// 1
|
|
// 2
|
|
// 2
|
|
// 2
|
|
}
|