GoLang Tutorial - Channels: Worker Pools
In this post, exclusively based on Go by Example: Worker Pools, we'll look at how to implement a worker pool using goroutines and channels.
Let's look at the following code:
The code: channel-worker-pools.go
We run several concurrent instances for the worker. These workers receive work on the jobs channel and send the corresponding results on results. We sleep a second per job to simulate an expensive task.
In order to use our pool of workers, we need to send them work and collect their results. We make 2 channels for this.
Then, starts up 3 workers, initially blocked because there are no jobs yet.
We send 5 jobs and then close that channel to indicate that's all the work we have.
Finally we collect all the results of the work.
Output:
Our running program shows the 5 jobs being executed by various workers. The program only takes less than 5 seconds despite doing about 5 seconds of total work because there are 3 workers operating concurrently.
Go Tutorial
- GoLang Tutorial - HelloWorld
- Calling code in an external package & go.mod / go.sum files
- Workspaces
- Workspaces II
- Visual Studio Code
- Data Types and Variables
- byte and rune
- Packages
- Functions
- Arrays and Slices
- A function taking and returning a slice
- Conditionals
- Loops
- Maps
- Range
- Pointers
- Closures and Anonymous Functions
- Structs and receiver methods
- Value or Pointer Receivers
- Interfaces
- Web Application Part 0 (Introduction)
- Web Application Part 1 (Basic)
- Web Application Part 2 (Using net/http)
- Web Application Part 3 (Adding "edit" capability)
- Web Application Part 4 (Handling non-existent pages and saving pages)
- Web Application Part 5 (Error handling and template caching)
- Web Application Part 6 (Validating the title with a regular expression)
- Web Application Part 7 (Function Literals and Closures)
- Building Docker image and deploying Go application to a Kubernetes cluster (minikube)
- Serverless Framework (Serverless Application Model-SAM)
- Serverless Web API with AWS Lambda
- Arrays vs Slices with an array left rotation sample
- Variadic Functions
- Goroutines
- Channels ("<-")
- Channels ("<-") with Select
- Channels ("<-") with worker pools
- Defer
- GoLang Panic and Recover
- String Formatting
- JSON
- SQLite
- Modules 0: Using External Go Modules from GitHub
- Modules 1 (Creating a new module)
- Modules 2 (Adding Dependencies)
- AWS SDK for Go (S3 listing)
- Linked List
- Binary Search Tree (BST) Part 1 (Tree/Node structs with insert and print functions)
- Go Application Authentication I (BasicAuth, Bearer-Token-Based Authentication)
- Go Application Authentication II (JWT Authentication)
Ph.D. / Golden Gate Ave, San Francisco / Seoul National Univ / Carnegie Mellon / UC Berkeley / DevOps / Deep Learning / Visualization
My YouTube channel