是否可以在System V共享内存中实现无锁循环队列（C++写，Python读）

Question

A lock free circular queue (single-reader single-writer) depends on atomic writes and a consistent view of the data for reads.

In it's simplest form you have a HEAD pointer, updated by the writer-process , and a sufficiently large array. The writer-process writes new data, then updates the HEAD pointer.

Presume the HEAD pointer is a 32 bit integer. C offers atomic write operations on that 32 bit integer. But if the reader-process is Python ( multiprocessing.shared_memory + numpy ), it's not at all obvious that Python can assume a consistent view of that 4-byte HEAD pointer, or even any guarantee that the HEAD write operation will occur after the data is written to the array.

Are there convenient ways to handle this between processes and languages?

Answer 1

You're mixing C and C++ here as well, but that's somewhat acceptable because they share a memory model.

The convenient way would be a CPython extension in C, using the same compiler as the other side of the shared memory.