Decomposing the design (or documentation) of large systems is a practical necessity but finding compositional development methods for concurrent software is technically challenging. This paper includes the development of a difficult example in order to draw out lessons about such methods. The concurrent garbage collector development is interesting in several ways; in particular, the final step of its development appears to be just beyond what can be expressed by rely/guarantee relations. This prompts an exploration of the limitations of this well-known method. Although the rely/guarantee approach is used, most of the lessons are more general.

中文翻译：

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基于并发垃圾收集器示例调查依赖/保证关系的限制

分解大型系统的设计（或文档）是一种实际需要，但发现作曲的并发软件的开发方法在技术上具有挑战性。本文包括一个困难的例子的发展，以便从这些方法中汲取教训。并发垃圾收集器的开发在几个方面很有趣；特别是，其发展的最后一步似乎超出了依赖/担保关系所能表达的范围。这促使人们探索这种众所周知的方法的局限性。尽管使用了依赖/保证方法，但大多数课程都比较笼统。