UTL::profiler is a single-header, easy-to-use C++17 profiler that measures the execution time of code blocks. It supports nested profiling, multi-threaded applications, and custom output formats. Simply include the header, wrap the code you want to profile with UTL_PROFILE macros, and link against a high-resolution timer if needed. The profiler automatically generates a report with hierarchical timings, making it straightforward to identify performance bottlenecks. It also provides the option to programmatically access profiling data for custom analysis.
The blog post "It is not a compiler error (2017)" explores a subtle bug related to floating-point comparisons in C++. The author demonstrates how seemingly innocuous code, involving comparing a floating-point value against zero after decrementing it in a loop, can lead to unexpected infinite loops. This arises because floating-point numbers have limited precision, and repeated subtraction of a small value from a larger one might never exactly reach zero. The post emphasizes the importance of understanding floating-point limitations and suggests using alternative comparison methods, like checking if the value is within a small tolerance of zero (epsilon comparison), or restructuring the loop condition to avoid direct equality checks with floating-point numbers.
HN users discuss integer overflow in C/C++, focusing on its undefined behavior and the security implications. Some highlight the dangers, especially in situations where the compiler optimizes away overflow checks based on the assumption that it can't happen. Others point out that -fwrapv can enforce predictable wrapping behavior, making code safer but potentially slower. The discussion also touches on how static analyzers can help catch these issues, and the inherent difficulties in ensuring complete safety in C/C++ due to the language's flexibility. A few commenters mention alternatives like Rust, which offer stricter memory safety and overflow handling. One commenter shares a personal anecdote about an integer underflow vulnerability they found in a C++ program, emphasizing the real-world impact of these seemingly theoretical problems.
Bjarne Stroustrup's "21st Century C++" blog post advocates for modernizing C++ usage by focusing on safety and performance. He highlights features introduced since C++11, like ranges, concepts, modules, and coroutines, which enable simpler, safer, and more efficient code. Stroustrup emphasizes using these tools to combat complexity and vulnerabilities while retaining C++'s performance advantages. He encourages developers to embrace modern C++, utilizing static analysis and embracing a simpler, more expressive style guided by the "keep it simple" principle. By moving away from older, less safe practices and leveraging new features, developers can write robust and efficient code fit for the demands of modern software development.
Hacker News users discussed the challenges and benefits of modern C++. Several commenters pointed out the complexities introduced by new features, arguing that while powerful, they contribute to a steeper learning curve and can make code harder to maintain. The benefits of concepts, ranges, and modules were acknowledged, but some expressed skepticism about their widespread adoption and practical impact due to compiler limitations and legacy codebases. Others highlighted the ongoing tension between embracing modern C++ and maintaining compatibility with existing projects. The discussion also touched upon build systems and the difficulty of integrating new C++ features into existing workflows. Some users advocated for simpler, more focused languages like Zig and Jai, suggesting they offer a more manageable approach to systems programming. Overall, the sentiment reflected a cautious optimism towards modern C++, tempered by concerns about complexity and practicality.
Summary of Comments ( 3 )
https://news.ycombinator.com/item?id=43680477
HN users generally praised the profiler's simplicity and ease of integration, particularly appreciating the single-header design. Some questioned its performance overhead compared to established profilers like Tracy, while others suggested improvements such as adding timestamp support and better documentation for multi-threaded profiling. One user highlighted its usefulness for quick profiling in situations where integrating a larger library would be impractical. There was also discussion about the potential for false sharing in multi-threaded scenarios due to the shared atomic counter, and the author responded with clarifications and potential mitigation strategies.
The Hacker News post titled "Show HN: Single-Header Profiler for C++17" has generated several comments discussing the linked single-header profiler. Here's a summary:
Ease of Use and Integration: Many commenters praised the simplicity and ease of integration of the profiler, emphasizing the advantage of it being a single header file. This makes it easy to drop into existing projects without complex build system modifications. Some appreciated the minimal setup required, contrasting it with more complex profiling tools.
Chrome Tracing Support: The integration with Chrome's tracing tools was a highlight for several users. They saw the ability to visualize the profiling data in Chrome's trace viewer as a significant benefit, offering a familiar and powerful interface for analysis.
Overhead Concerns: A few commenters raised concerns about the potential performance overhead introduced by the profiler. While acknowledging its usefulness for quick profiling, they cautioned against using it in performance-sensitive production code. One commenter specifically asked about the overhead, but there wasn't a definitive answer provided in the thread.
Comparison with Existing Profilers: The profiler was compared to other existing profiling tools like Tracy and Instruments. Some users expressed a preference for the simplicity of this single-header solution over more complex alternatives, while others highlighted the advanced features offered by established profilers. One commenter specifically mentioned finding Tracy superior.
Specific Feature Requests and Suggestions: There were specific suggestions for improvements, such as adding support for custom allocators and the ability to disable instrumentation for certain functions or scopes. Another commenter requested more documentation and examples.
Appreciation for the Project: Overall, the comments expressed appreciation for the project, recognizing its value as a quick and easy-to-use profiling tool. Several users indicated their intention to try it out in their own projects.
Lack of Extensive Discussion on Accuracy: While performance overhead was discussed, there wasn't a significant discussion about the accuracy of the profiler's measurements.
In summary, the comments on Hacker News generally viewed the single-header profiler positively, praising its simplicity and ease of use, particularly the Chrome tracing integration. However, some concerns were raised regarding potential overhead and comparisons were made to other existing profiling solutions. The thread also contained specific requests for features and improvements.