channel

What are channels used for?

由 别来无恙 提交于 2019-12-17 09:32:13
问题 When looking through some Go code I found the following: ch := make(chan int) I looked up in a online tutorial how Go Channels work: https://tour.golang.org/concurrency/2 But I find this example unclear. Can someone give me a easy explanation and an example of the use of channels? 回答1: chan is a channel in Golang. In simple word you can think it as a box in which you put a item at one end and then pick it from other end. Unbuffered Channels Buffered Channel This is the small code I have

Redirect test results for tcltest

由 安稳与你 提交于 2019-12-13 23:37:19
问题 I like use tcltest in my daily testing tasks. But test results i can only see in console, so after each test run i need to switch to that console, to find results. Аccording to tcltest documentation, there is option outputChannel . This option allow redirect test results to pipe or channel and then display anywhere i want. So i try to create this channel: set logger [ open "|bash -c \"while true;do sleep 1; while read mess;do debug=\\\"\$debug \n \$mess\\\";done; if \\\[\\\[ \$debug != \\\"\\

Youtube channel livestream embedded doesn't work

由 时间秒杀一切 提交于 2019-12-13 21:26:50
问题 I'm using iframe for embed youtube channel in my site, but it shows "An error ocurred. Please try again.". Strangely, if I set another channel ID it works. The channel ID that doesn't work The channel ID that works I copied the debug information just in case: { "cpn": "hWjSQIlGKWCb1Abv", "vct": "0.000", "vd": "NaN", "vpl": "", "vbu": "", "vpa": "1", "vsk": "0", "ven": "0", "vpr": "1", "vrs": "0", "vns": "0", "vec": "null", "vvol": "1", "creationTime": 65805, "totalVideoFrames": 0,

Java FileChannel.size() vs File.length()

由 我们两清 提交于 2019-12-13 21:13:49
问题 Are there any circumstances where FileChannel.size() and File.length() will be different? Please see the code example below: File file = new File(name); FileInputStream stream = new FileInputStream(file); FileChannel channel = stream.getChannel(); long channel_size = channel.size(); long file_length = file.length(); 回答1: They can be different because the new File(name).length() always checks the path given. When you use FileInputStream , you attach to that file regardless of what happens to

Google App Engine channel token is invalid

由 半城伤御伤魂 提交于 2019-12-13 18:03:22
问题 I'm trying to open a channel by copying and pasting a token into an input box, however the console returns, Invalid+token. Here is the code for localhost:8080/ <html> <head> <script type="text/javascript" src="https://talkgadget.google.com/talkgadget/channel.js"></script> <script> function OpenChannel(){ channel = new goog.appengine.Channel(document.getElementById('Token').value); socket = channel.open(); socket.onmessage = function(message){ console.log(message); } socket.onopen = function()

Checking channel length becomes unresponsive in `for{ len(c) }`

由 纵饮孤独 提交于 2019-12-13 11:22:56
问题 The following program never prints "Full". With fmt.Println(len(choke)) uncommented, the program outputs "Full" when the channel is full. package main import ( "fmt" ) func main() { choke := make(chan string, 150000) go func() { for i := 0; i < 10000000; i++ { choke <- string(i) fmt.Println("i=", i) } }() for { //fmt.Println(len(choke)) if len(choke) >= 150000 { fmt.Println("Full") } } } @tim-heckman explained the cause of this behavior in OP. How do I detect a channel is full without using a

How to write my own Sleep function using just time.After?

由 ↘锁芯ラ 提交于 2019-12-13 09:13:00
问题 I'm trying to write my own sleep function equivalent to time.Sleep using time.After in Go. Here's the code. First attempt: func Sleep(x int) { msg := make(chan int) msg := <- time.After(time.Second * x) } Second attempt: func Sleep(x int) { time.After(time.Second * x) } Both return errors, can someone explain to me how to write a sleep function equivalent to time.Sleep using time.After and if possible when do I use channel? 回答1: time.After() returns you a channel. And a value will be send on

Reliable way to ensure a Go channel does not block

由 风流意气都作罢 提交于 2019-12-13 08:24:28
问题 I'm looking for a reliable to way to make sure an empty channel in Go does not block my execution. I have to iterate through a number of channels in a particular order (kind of priorities), and once I find one with items in it, read one. Currently I do something in a similar way: if len(myChannel) > 0 { // Possible issue here: length could have changed to 0 making this blocking elm := <- myChannel return elm } In theory this could result into too-long of waiting, while a different channel

How to collect values from N goroutines executed in a specific order?

由 ぃ、小莉子 提交于 2019-12-13 02:48:29
问题 Below is a struct of type Stuff. It has three ints. A Number , its Double and its Power . Let's pretend that calculating the double and power of a given list of ints is an expensive computation. type Stuff struct { Number int Double int Power int } func main() { nums := []int{2, 3, 4} // given numbers stuff := []Stuff{} // struct of stuff with transformed ints double := make(chan int) power := make(chan int) for _, i := range nums { go doubleNumber(i, double) go powerNumber(i, power) } // How

Notification Channel - Is It Possible to Change LightColor After It's Been Set?

由 对着背影说爱祢 提交于 2019-12-13 00:29:49
问题 I'm trying to change setLightColor with a colour returned from a JavaScript Interface. Unfortunately, NotificationCompat.Builder(context, CHANNEL_ID).setLights has absolutely no sway on API >= 26, so I can't use Intent.putExtra or anything similar. Is it even possible to change it after it's already been set? I would like it to be dynamic. EDIT There seems to be some misconception on what I want. I don't want to touch the Broadcast Reciever . It works just fine. I want to change the
订阅 channel