Mutex and RWMutex are not associated with goroutines, but RWMutex is obviously more suitable for scenarios with more reads and less writes. For read performance only, RWMutex is higher than Mutex, because multiple reads of rwmutex can coexist.
Go has included support for versioned modules as proposed here - https://golang.org/design/24301-versioned-go since 1.11. The initial prototype vgo was announced - https://research.swtch.com/vgo in February 2018. In July 2018, versioned modules landed in the main Go repository.
A Pool is a set of temporary objects that may be individually saved and retrieved.
When there is an expensive object you have to create it frequently, it can be very beneficial to use sync.Pool.
Any item stored in the Pool may be removed automatically at any time without notification. If the Pool holds the only reference when this happens, the item might be deallocated.
A Pool is safe for use by multiple goroutines simultaneously.
Pool’s purpose is to cache allocated but unused items for later reuse, relieving pressure on the garbage collector. That is, it makes it easy to build efficient, thread-safe free lists. However, it is not suitable for all free lists.
premailer-rails is a drop in solution for styling HTML emails with CSS without having to do the hard work yourself.
Styling emails is not just a matter of linking to a stylesheet. Most clients, especially web clients, ignore linked stylesheets or <style> tags in the HTML. The workaround is to write all the CSS rules in the style attribute of each tag inside your email. This is a rather tedious and hard to maintain approach.
Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms.
These functions require great care to be used correctly. Except for special, low-level applications, synchronization is better done with channels or the facilities of the sync package. Share memory by communicating; don’t communicate by sharing memory.
In software engineering, the singleton pattern is a software design pattern that restricts the instantiation of a class to one “single” instance. This is useful when exactly one object is needed to coordinate actions across the system. The term comes from the mathematical concept of a singleton.
You should be aware of Singletons in multi-threaded applications. If they hold some kind of mutable data, it could lead to unexpected results, so the synchronization mechanism should be considered.
Since we are talking about the Dart programming language in this series, you should know that Dart is a single-threaded programming language and its code runs in a little isolated space on the machine, called isolate. Hence, you should not worry about the thread-safety when implementing Singletons in Dart as long as you do not create a new separate isolate from the code by yourself.
Recently I needed to concatenate a string and an int in Go. I’ve gathered and organized all of them in this post, including full working examples for each.
Variable is the name given to a memory location to store a value of a specific type. There are various syntaxes to declare variables in Go. Let’s look at them one by one.
Since Go is strongly typed, variables declared as belonging to one type cannot be assigned a value of another type.
Viper is a complete configuration solution for Go applications including 12-Factor apps. It is designed to work within an application, and can handle all types of configuration needs and formats. It supports: