channel

问题 I have a project in django 2.0 nad django-channlels 2.0 which I need to host I followed the documentation and I was able to run channels on localhost along with redis but when I hosted on pythonanywhere,it showed it doesnot support websocket, so then I hosted on heroku,but there they were asking for verification of credit card info which i dont have to run redis.Are there additional hosting website whre I can rrun redis erver for free Or is it poosible to implement channels without channel

问题 Does order in which the Goroutines block on a channel determine the order they will unblock? I'm not concerned with the order of the messages that are sent (they're guaranteed to be ordered), but the order of the Goroutines that'll unblock. Imagine a empty Channel ch shared between multiple Goroutines (1, 2, and 3), with each Goroutine trying to receive a message on ch . Since ch is empty, each Goroutine will block. When I send a message to ch , will Goroutine 1 unblock first? Or could 2 or 3

问题 I need to start a huge amount of goroutines and wait for their termination. The intuitive way seems to use a channel to wait till all of them are finished : package main type Object struct { //data } func (obj *Object) Update(channel chan int) { //update data channel <- 1 return } func main() { channel := make(chan int, n) list := make([]Object, n, m) for { for _, object := range list { go object.Update(channel) } for i := 0; i < n; i++ { <-channel } //now everything has been updated. start

问题 I've been attempting to take a swing at concurrency in Golang by refactoring one of my command-line utilities over the past few days, but I'm stuck. Here's the original code (master branch). Here's the branch with concurrency (x_concurrent branch). When I execute the concurrent code with go run jira_open_comment_emailer.go , the defer wg.Done() never executes if the JIRA issue is added to the channel here, which causes my wg.Wait() to hang forever. The idea is that I have a large amount of

问题 I try to write a complex program with parallel goroutines. It is my first program with channels ;) Each goroutine returns an array and, unfortunately, the result is "random". If I run 10 times the program, I have 10 different results :( This is an over simplification of my program, the results is good (maybe because it is too simple) but when I run it with -race argument, there is 4 data races. I tried to had a close() function but it did not worked. May you help me to find the mistake ?

问题 I am trying to play around with go to make some kind of port scanner using the stdlib. This is more of an exercise than anything else, so please don't comment on the logic involved. Looking at the following code: package main import ( "flag" "fmt" "net" "time" "strings" "strconv" "log" "sync" ) var commonPorts = map[int]string { 21: "ftp", 22: "sftp", 80: "http", 110: "pop3", 143: "imap", 443: "https", 631: "ipp", 993: "imaps", 995: "pop3s", } type OP struct { mu sync.Mutex ports []string }

问题 I have a command XYZ sent over a channel using the sendall() channel = ssh.invoke_shell() channel.sendall('XYZ\n') response = channel.recv(2000) I should have the entire output right there, but then I notice that in the last line of the output that I do receive, there is a "--more--" at the end. Like the one that you get when you use the 'less' command. As a result, the channel is still waiting for more output because the buffer is not empty (more output is expected) and the command is

问题 In the end, my ultimate goals are: Read from a URL (what this question is about) Save the retrieved [PDF] content to a BLOB field in a DB (already have that nailed down) Read from the BLOB field and attach that content to an email All without going to a filesystem The goal with the following method is to get a byte[] that can be used downstream as an email attachment (to avoid writing to disk): public byte[] retrievePDF() { HttpClient httpClient = new HttpClient(); GetMethod httpGet = new

问题 I'm here to find out the most idiomatic way to do the follow task. Task : Write data from a channel to a file. Problem : I have a channel ch := make(chan int, 100) I need to read from the channel and write the values I read from the channel to a file. My question is basically how do I do so given that If channel ch is full, write the values immediately If channel ch is not full, write every 5s. So essentially, data needs to be written to the file at least every 5s (assuming that data will be

问题 client channel is not in writable state in netty . Can any experts guide me to find-out the reason why the channel is always not in writable state? since it is not in writable state our threads are in sleep mode. We analyzed the state of threads using Thread dump, added a counter in the following loop and it waits for a minute and then exit from the loop. But i really want to figure-out the reason for not writable state. Is the channel is remains in ctx after the closing of channel(If the EOF