Unix系统中的原子操作（2010）

This 2010 article explores the scope and limitations of atomic operations within Unix systems, focusing particularly on atomicity guarantees in file systems and inter-process communication (IPC). Through concrete examples like `open(O_CREAT|O_EXCL)`, `link`, `rename`, and `mkdir` system calls, the author illustrates their atomic behavior in concurrent environments and how this atomicity ensures data integrity and prevents race conditions. The article also discusses that atomicity is not universal; for instance, writing file content is typically not atomic, requiring developers to employ locks or other synchronization mechanisms. Furthermore, it touches upon the atomic properties of pipes and Unix domain sockets in certain scenarios. The piece underscores the critical role of understanding Unix atomic operations for writing robust, concurrent-safe programs, advising developers to clearly distinguish between inherently atomic operations and those requiring additional synchronization.