Many Internet of Things and embedded projects are event-driven, and therefore require asynchronous and concurrent programming. Current proposals for C++20 suggest that coroutines will have native language support. It is timely to survey the current use of coroutines in embedded systems development. This paper investigates existing research which uses or describes coroutines on resource-constrained platforms. The existing research is analysed with regard to: software platform, hardware platform and capacity; use cases and intended benefits; and the application programming interface design used for coroutines. A systematic mapping study was performed, to select studies published between 2007 and 2018 which contained original research into the application of coroutines on resource-constrained platforms. An initial set of 566 candidate papers were reduced to only 35 after filters were applied, revealing the following taxonomy. The C & C++ programming languages were used by 22 studies out of 35. As regards hardware, 16 studies used 8- or 16-bit processors while 13 used 32-bit processors. The four most common use cases were concurrency (17 papers), network communication (15), sensor readings (9) and data flow (7). The leading intended benefits were code style and simplicity (12 papers), scheduling (9) and efficiency (8). A wide variety of techniques have been used to implement coroutines, including native macros, additional tool chain steps, new language features and non-portable assembly language. We conclude that there is widespread demand for coroutines on resource-constrained devices. Our findings suggest that there is significant demand for a formalised, stable, well-supported implementation of coroutines in C++, designed with consideration of the special needs of resource-constrained devices, and further that such an implementation would bring benefits specific to such devices.
翻译:许多事物的互联网和嵌入式项目都是由事件驱动的,因此需要非同步的同步和同步的编程。 C++20目前的建议表明,共同路线将获得本地语言支持。现在及时调查嵌入式系统开发中当前使用共同路线的情况。本文调查了在资源限制平台上使用或描述共同路线的现有研究。对现有研究进行了分析,涉及:软件平台、硬件平台和能力;使用案例和预期效益;以及用于连流处理的应用程序程序接口设计。进行了系统化的绘图研究,以选择2007年至2018年间出版的研究报告,其中含有对资源限制式平台应用共同路线的原始研究。在应用过滤器后,初步将566份候选论文减少到仅35份,揭示了以下分类学。C & C++编程语言的22项研究得到了使用。在硬件方面,16项研究使用了8或16位处理器,13种使用了32位处理器。 四种最常见的用途案例是调子(17份文件)、网络通信(15份)、感官读(9)和数据链流(7份),用于资源限制式平台上的大量资源需求(12项预估定序),用于成本的流程。