The blog post argues for a standardized, cross-platform OS API specifically designed for timers. Existing timer mechanisms, like POSIX's timerfd and Windows' CreateWaitableTimer, while useful, differ significantly across operating systems, complicating cross-platform development. The author proposes a new API with a consistent interface that abstracts away these platform-specific details. This ideal API would allow developers to create, arm, and disarm timers, specifying absolute or relative deadlines with optional periodic behavior, all while handling potential issues like early wake-ups gracefully. This would simplify codebases and improve portability for applications relying on precise timing across different operating systems.
The blog post "The missing cross-platform OS API for timers" by Gaultier.github.io explores the challenges and complexities of implementing timers across different operating systems, arguing for a standardized, cross-platform OS-level API. The author begins by highlighting the ubiquitous need for timers in software development, from simple delays to complex scheduling tasks, and emphasizes the performance implications of timer accuracy and efficiency, especially in latency-sensitive applications like games and high-frequency trading.
The post then dives into the intricacies of existing timer mechanisms on various operating systems. It describes how POSIX timers, while offering a relatively consistent interface on Unix-like systems, have limitations related to signal handling and potential issues with signal coalescing, where multiple timer expirations might be delivered as a single signal. On Windows, the author explains the different timer APIs available, such as CreateTimerQueueTimer and SetWaitableTimer, pointing out their specific strengths and weaknesses regarding precision, resource management, and complexity. The disparities between these platforms, the post argues, necessitate developers to write platform-specific code, increasing development time and introducing potential inconsistencies in behavior.
The core proposal of the blog post is to introduce a new, unified OS-level API for timers that would abstract away the underlying platform differences. This proposed API should ideally offer features like high resolution, support for both one-shot and periodic timers, efficient callback mechanisms, and the ability to associate timers with specific threads or processes for better control and organization. The author suggests that this API could be implemented as a thin abstraction layer on top of existing OS mechanisms, allowing for efficient utilization of underlying hardware capabilities while presenting a consistent interface to developers. This would significantly simplify cross-platform development by eliminating the need for custom timer implementations and ensuring predictable behavior across different environments.
Furthermore, the blog post discusses the potential benefits of such a standardized API, including improved code portability, reduced development costs, and enhanced performance. The author emphasizes how a well-designed API could facilitate the creation of more robust and efficient applications by providing developers with a reliable and easy-to-use timer mechanism. The post concludes with a call to action, encouraging operating system developers to consider the benefits of a unified timer API and collaborate on its design and implementation. The ultimate goal, the author states, is to empower developers with a powerful and versatile tool for managing time-related operations across various platforms, ultimately leading to better software.
Summary of Comments ( 18 )
https://news.ycombinator.com/item?id=42915437
The Hacker News comments discuss the complexities of cross-platform timer APIs, largely agreeing with the article's premise. Several commenters highlight the difficulties introduced by different operating systems' power management features, impacting timer accuracy and reliability. Specific challenges like signal coalescing and the lack of a unified interface for monotonic timers are mentioned. Some propose workarounds like busy-waiting for short durations or using platform-specific code for optimal performance. The need for a standardized API is reiterated, with suggestions for what such an API should offer, including considerations for power efficiency and different timer resolutions. One commenter points to the challenges of abstracting away hardware differences completely, suggesting the ideal solution may involve a combination of OS-level improvements and application-specific strategies.
The Hacker News post "The missing cross-platform OS API for timers" generated several comments discussing the challenges and nuances of timer implementations across different operating systems.
Several commenters highlighted the inherent difficulties in creating a truly cross-platform timer API due to the varying underlying mechanisms and priorities of each OS. One user pointed out the complexities introduced by power management, specifically how different systems handle timers during sleep or low-power states. This difference in behavior makes it difficult to abstract away the platform-specific details into a unified API. Another commenter echoed this sentiment, emphasizing that timers are often deeply integrated with the OS scheduler and power management, making a universal solution challenging. They also pointed to the trade-off between accuracy and power efficiency, which further complicates a cross-platform approach.
The discussion also touched on the existing solutions and their limitations. One comment mentioned
kqueueon macOS/BSD platforms and epoll on Linux, acknowledging their suitability for event-driven programming but also their lack of a direct cross-platform equivalent. The lack of a unified interface across these different mechanisms was reiterated by another commenter who emphasized the need to deal with distinct APIs and behaviors on each platform.Some commenters delved into specific use cases and challenges, such as dealing with high-resolution timers and the limitations imposed by system clock granularity. One commenter discussed the difficulties in achieving precise timing in JavaScript, citing the impact of browser event loops and garbage collection.
The complexities of timer coalescing were also brought up. One commenter explained how operating systems might group timer events to reduce CPU wakeups and improve power efficiency, which can affect the precision of timer execution. Another commenter noted that this behavior can be unpredictable and difficult to account for in a cross-platform API.
Finally, a few comments explored alternative approaches, like using a dedicated thread for timer management, although this was acknowledged as potentially resource-intensive. The discussion ultimately highlighted the significant challenges in designing a truly cross-platform timer API, with the conclusion being that a "one-size-fits-all" solution might not be feasible due to the inherent differences in OS architectures and priorities.