Concurrent map using channels

safe_map.go

package main

import "fmt"

type safeMap struct {
	data            map[string]string
	readch, writech chan chan string
}

func newSafeMap() *concurrentMap {
	m := &safeMap{
		data:    make(map[string]string),
		readch:  make(chan chan string),
		writech: make(chan chan string),
	}
	go func() {
		for {
			select {
			case ch := <-m.readch:
				key := <-ch
				ch <- m.data[key]
			case ch := <-m.writech:
				key := <-ch
				value := <-ch
				m.data[key] = value
			}
		}
	}()
	return m
}

func (m *safeMap) get(key string) string {
	ch := make(chan string)
	m.readch <- ch
	ch <- key
	return <-ch
}

func (m *safeMap) set(key, value string) {
	ch := make(chan string)
	m.writech <- ch
	ch <- key
	ch <- value
}

func main() {
	m := newSafeMap()
	done := make(chan bool)
	go func() {
		m.set("foo", "a")
		done <- true
	}()
	m.set("bar", "b")
	<-done
	fmt.Println(m.get("foo"))
}