channel

Maybe I'm just not reading the spec right or my mindset is still stuck with older synchronization methods, but what is the right way in Go to send one type as receive something else as a response? One way I had come up with was package main import "fmt" type request struct { out chan string argument int } var input = make(chan *request) var cache = map[int]string{} func processor() { for { select { case in := <- input: if result, exists := cache[in.argument]; exists { in.out <- result } result := fmt.Sprintf("%d", in.argument) cache[in.argument] = result in.out <- result } } } func main() { go

I'm working on a concurrent Go library, and I stumbled upon two distinct patterns of synchronization between goroutines whose results are similar: Using Waitgroup var wg sync.WaitGroup func main() { words := []string{ "foo", "bar", "baz" } for _, word := range words { wg.Add(1) go func(word string) { time.Sleep(1 * time.Second) defer wg.Done() fmt.Println(word) }(word) } // do concurrent things here // blocks/waits for waitgroup wg.Wait() } Using Channel func main() { words = []string{ "foo", "bar", "baz" } done := make(chan bool) defer close(done) for _, word := range words { go func(word

For one of my requirement I have to create N number of worker go routines, which will be monitored by one monitoring routine. monitoring routine has to end when all worker routines completes. My code ending in deadlock, please help. import "fmt" import "sync" import "strconv" func worker(wg *sync.WaitGroup, cs chan string, i int ){ defer wg.Done() cs<-"worker"+strconv.Itoa(i) } func monitorWorker(wg *sync.WaitGroup, cs chan string) { defer wg.Done() for i:= range cs { fmt.Println(i) } } func main() { wg := &sync.WaitGroup{} cs := make(chan string) for i:=0;i<10;i++{ wg.Add(1) go worker(wg,cs,i

Have anyone used ZmqSocket.js successfully? I'd like to know how can it be used to establish a safe channel between the browser and a zeromq server app. Is there other/better options for such use case? I've never used ZmqSocket.js, but I can tell you that it's probably not a good idea (yet). This is because zmq still assumes that both peers know the protocol well and will blow up if given invalid data (they are working on fixing that, though). What I do right now is have a simple node.js based proxy that uses socket.io to communicate with browsers and pushes data in (and reads from) a zeromq

It seems the only way to make the GAE Channel API financially viable is to implement some kind of pooling mechanism (one of the senior app engine product managers even told me this when I emailed them about the exorbitant price) to reuse channels that have not yet expired. I've been brainstorming ways (places) to implement a channel pool, but each method I think of has some pretty serious drawbacks. Static memory of a Servlet -- Good, but will drop quite a bit of open channels when a new VM instance opens and/or a client gets passed from one VM to another. Memcache -- At least the memory is

I have a client app that tries every 10 seconds to send a message over a WCF web service. This client app will be on a computer on board a ship, which we know will have spotty internet connectivity. I would like for the app to try to send data via the service, and if it can't, to queue up the messages until it can send them through the service. In order to test this setup, I start the client app and the web service (both on my local machine), and everything works fine. I try to simulate the bad internet connection by killing the web service and restarting it. As soon as I kill the service, I

Can anyone tell me, is there any option to customize wifi direct channels? I need to customize it not only between ch1, ch6 and ch11, but also in another channels selected by me. How can I do that? In order to change the channel of the Wifi Direct of your device you need to do the following: 1- Root your phone 2- Download any File manager App: Such as ES File Explorer 3- On ES File Explorer, go to Tools, then turn ON the Root Explorer and click on it then mount RW 4- Using ES File Explorer, go to Device -> Data -> Misc -> Wifi -> p2p_supplicant.conf and change the p2p_oper_channel to whatever

After (briefly) reviewing the Go language spec, effective Go, and the Go memory model, I'm still a little unclear as to how Go channels work under the hood. What kind of structure are they? They act kind of like a thread-safe queue /array. Does their implementation depend on the architecture? mna The source file for channels is (from your go source code root) in /src/pkg/runtime/chan.go . hchan is the central data structure for a channel, with send and receive linked lists (holding a pointer to their goroutine and the data element) and a closed flag. There's a Lock embedded structure that is