C++ libraries that implement Go goroutines or Go channels?

I'm working with a medium-sized C++ code base which is currently entirely single-threaded. The time has come, however, to pursue concurrency and parallelism for performance gains. I'm very...

Tour of Go exercise #10: Crawler

I'm going through the Go Tour and I feel like I have a pretty good understanding of the language except for concurrency. slide 10 is an exercise that asks the reader to parallelize a web crawler...

How to check a channel is closed or not without reading it?

This is a good example of workers & controller mode in Go written by @Jimt, in answer to "Is there some elegant way to pause & resume any other goroutine in golang?" package main import ( ...

How to multiply duration by integer?

To test concurrent goroutines, I added a line to a function to make it take a random time to return (up to one second) time.Sleep(rand.Int31n(1000) * time.Millisecond) However when I compiled, I...

What is the nodejs setTimeout equivalent in Golang?

I am currently studying, and I miss setTimeout from Nodejs in golang. I haven't read much yet, and I'm wondering if I could implement the same in go like an interval or a loopback. Is there a way...

What are the three background goroutines in a Go program?

Go seems to always have at least 4 goroutines running at any given time. What are the other three that are not the main goroutine? http://play.golang.org/p/MQBiLmHXBK package main import...

How to identify a goroutine?

Let's say I have a stacktrace for a bunch of goroutines, e. g.: goroutine 5633 [select]: net/http.(*persistConn).writeLoop(0xc21303ac00) /usr/lib/go/src/pkg/net/http/transport.go:791...

Go, tcp too many open files debug

Here's a straightforward Go http (tcp) connection test script func main() { ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { fmt.Fprintln(w,...

golang too many open files in go function, goroutine

package main import ( "os" "sync" ) func main() { var wg sync.WaitGroup wg.Add(1024 * 1024) for i := 0; i < (1024 * 1024); i++ { go func(index int) { if...

Close all goroutines when HTTP request is cancelled

I am making a web crawler. I'm passing the url through a crawler function and parsing it to get all the links in the anchor tag, then I am invoking same crawler function for all those urls using...

Why do these goroutines not scale their performance from more concurrent executions?

Background = I am currently working on my bachelor thesis and basically my task is to optimise a given code in Go, i.e. make it run as fast as possible. First, I optimised the serial function and...

Run Goroutines on separate processes (multiprocessing)

I currently have a MQTT code that can subscribe to a topic, print out the messages received, then publish further instructions to a new topic. The subscribing/printing is completed in one...

How pass numpy array from Python to Golang function

I'm trying create library using with Golang for working in Python. But I have one problem: I can't pass numpy array to go function. Please, help me solve problem. My code: main.go: package...

Goroutines (cgo): unexplained OS thread spawns when using goroutines

I am using go to parallelize 2d convolutions where the convolution (implemented in go) is happening in a c-archive included in a C binary (where the go code is called). No calls are made from the...

pq: sorry, too many clients already

I am getting pq: sorry, too many clients already error when I am calling the GetMessages() multiple times. Please find the updated code: main() code func main() { dbConn, err := InitDB() if...

How to implement pipeline to goroutines?

I need some help on understanding how to use pipeline to get data to transfer from one goroutine to another. I read the golang blogpost on pipeline, I understood it but couldn't fully put it into...

GoLang service can't hit Postgres using docker compose

I have an HTML service written in Go. It uses Postgres, but when bringing it all together using docker compose I get " dial tcp 0.0.0.0:5432: connect: connection refused" Works when building...

How to correctly set Mock Row and Query for go-sqlmock

I'm setting up testing in golang. I use go-sqlmock to test mysql connection. But sqlmock.NewRows and mock.ExpectQuery does not work well with error. I want to know how to resolve this...

Stop a gouroutine after a period of time

Is it concurrent safe to Stop a gouroutine after a period of time, like this? Code: (Note: data race since ok changes in another goroutine): package main import ( "fmt" "time" ) func...

mongorestore failing on shard cluster v4.2.x | Error: "panic: close of closed channel"

Scenario: I had a standalone MongoDB Server v3.4.x where I had several DBs and collections respectively. As the plan was to upgrade to lastest 4.2.x, I have created a mongo dump of all...

How to exit when the first error occurs for one of the goroutines within a wait Group?

func getRecords(ctx context.Context, ids *[]Id) error { ctx, cancel := context.WithTimeout(ctx, DefaultTimeout) defer cancel() var wg sync.WaitGroup size := len(*ids) ...

glfw pkg-config error when building a fyne app

Golang code: package main import ( "fyne.io/fyne/app" "fyne.io/fyne/widget" ) func main() { application := app.New() window = application.NewWindow("Hello rohan") ...

Unable to deploy mongodb community operator in openshift

Im trying to deploy the mongodb community operator in openshift 3.11 using the following commands git clone https://github.com/mongodb/mongodb-kubernetes-operator.git cd...

How to use session-manager-plugin command

I want to use session-manager-plugin in python code. The code is written as follows import boto3 from boto3.session import Session import subprocess AWS_REGION = "ap-northeast-1" AWS_PROFILE =...

Failed to create new OS thread (have 2 already; errno=22)

I have mac with M1 and if i try to run docker container with nginx-proxy by jwilder, I got this error: api_clever4sms_nginx-proxy | runtime: failed to create new OS thread (have 2 already;...

Fixing runtime: failed to create new OS thread (have 2 already; errno=22) in Docker

I'm using Mac OS Big Sur with an M1 chip. If I try to run the docker image webdevops/php-apache, I get the following error % docker run -it webdevops/php-apache WARNING: The requested image's...

Golang with ffmpeg dynamic video Encode

Am trying to encode the videos with Golang ffmpeg. Am not able to get the video file, it shows this error invalid character '-' in numeric literal Postman: This is my code: package main import...

Error running ClickHouse Docker on MacBook M1

I'm running ClickHouse Docker image on MacBook M1 and getting the following error. clickhouse-02_1 | runtime: failed to create new OS thread (have 2 already; errno=22) clickhouse-02_1 |...

runtime: failed to create new OS thread (have 2 already; errno=22) in Docker: Elasticsearch

I am pulling Elasticsearch image in my docker compose. It looks like this es: image: elasticsearch:5.6.4 restart: "always" environment: - bootstrap.memory_lock=true -...

Golang - race condition using go-routine

I tried to use the race flag to my program and issue found :( The func is the following func (g *WaitingErrorGroup) Start(run func() (bool, error)) { g.g.Start(func() { requeue, err :=...