The author argues that Go channels, while conceptually appealing, often lead to overly complex and difficult-to-debug code in real-world scenarios. They contend that the implicit blocking nature of channels introduces subtle dependencies and makes it hard to reason about program flow, especially in larger projects. Error handling becomes cumbersome, requiring verbose boilerplate and leading to convoluted control structures. Ultimately, the post suggests that callbacks, despite their perceived drawbacks, offer a more straightforward and manageable approach to concurrency, particularly when dealing with complex interactions and error propagation. While channels might be suitable for simple use cases, their limitations become apparent as complexity increases, leading to code that is harder to understand, maintain, and debug.
In a 2016 blog post titled "Go channels are bad (and you should feel bad)," author J.T. Olio expresses a highly critical perspective on Go's channels, arguing that while superficially appealing, they introduce significant complexities and ultimately hinder rather than help concurrent programming. Olio contends that channels, marketed as a simplified approach to concurrency, create an illusion of ease that masks underlying difficulties.
Olio begins by acknowledging the initial attractiveness of channels, particularly for those transitioning from more complex concurrency models. He admits they offer a seemingly straightforward mechanism for inter-process communication. However, he swiftly pivots to critique their actual implementation, asserting that the simplicity is deceptive. He argues that the mental model of channels as simple queues is inaccurate and leads to unexpected behavior in more complex scenarios.
The author then delves into several specific pain points associated with using channels. He discusses the difficulty of debugging channel-based code, highlighting the lack of clear error messages and the challenge of tracing data flow through a network of channels. He argues that this opacity makes it significantly harder to identify and resolve issues compared to more traditional concurrency mechanisms.
Olio also criticizes the performance implications of channels. He suggests that the overhead associated with channel operations can be substantial, particularly in high-throughput applications. He contends that this performance cost can negate the perceived benefits of using channels, leading to slower and less efficient code.
Furthermore, the author takes issue with the inflexibility of channels. He argues that their fixed typing and unidirectional nature can restrict the expressiveness of code and force developers into awkward workarounds. He contrasts this with the more adaptable nature of traditional concurrency primitives, suggesting they offer greater freedom in designing concurrent algorithms.
The blog post concludes with a strong recommendation against using channels in Go programs. Olio urges developers to reconsider their reliance on channels and explore alternative approaches to concurrency, suggesting that these alternatives, while perhaps initially more complex, ultimately offer greater control, performance, and debuggability. He posits that the long-term benefits of these alternatives outweigh the perceived initial simplicity of channels.
Summary of Comments ( 67 )
https://news.ycombinator.com/item?id=43670373
HN commenters largely disagree with the article's premise. Several point out that the author's examples are contrived and misuse channels, leading to unnecessary complexity. They argue that channels are a powerful tool for concurrency when used correctly, offering simplicity and efficiency in many common scenarios. Some suggest the author's preferred approach of callbacks and mutexes is more error-prone and less readable. A few commenters mention the learning curve associated with channels but acknowledge their benefits once mastered. Others highlight the importance of understanding the appropriate use cases for channels, conceding they aren't a universal solution for every concurrency problem.
The Hacker News post "Go channels are bad (2016)" has generated a substantial discussion with a variety of viewpoints on the use of channels in Go. Several commenters challenge the author's premise, arguing that the issues presented stem from misapplication of channels rather than inherent flaws.
One recurring theme is the critique of the author's examples. Commenters point out that the use of unbuffered channels for signaling across goroutines, as demonstrated in the article, is often an anti-pattern. They suggest buffered channels or alternative synchronization mechanisms like
sync.WaitGroupwould be more appropriate for the scenarios presented. This challenges the author's claim that channels inherently lead to complex and error-prone code.Some commenters highlight the importance of context and experience when using channels. They acknowledge that channels can be misused, leading to the problems described in the article, but argue that with proper understanding, channels are a powerful tool for concurrency management. The idea that channels are "bad" is therefore considered an oversimplification.
Another line of discussion revolves around the comparison between channels and other concurrency models. Some commenters mention callbacks and promises as alternatives, but acknowledge the benefits of channels in terms of structuring concurrent code and avoiding callback hell. The discussion explores the trade-offs between different approaches and highlights the strengths of channels in specific scenarios.
Several commenters defend the use of channels, citing their effectiveness in building robust and concurrent systems. They argue that the issues raised in the article can be avoided with good design practices and a proper understanding of how channels work. They point to real-world projects where channels have proven to be a valuable asset for concurrency management.
The concept of "mechanical sympathy" is also brought up, suggesting that developers should understand the underlying mechanics of channels to use them effectively. This reinforces the idea that the problems highlighted in the article are likely due to misuse rather than inherent flaws in the concept of channels.
Overall, the comments section presents a balanced perspective. While acknowledging the potential pitfalls of using channels incorrectly, many commenters argue that the author's conclusion is overly negative and that channels remain a powerful tool for concurrent programming in Go when used correctly. The discussion provides valuable insights into best practices and common misconceptions surrounding the use of Go channels.