Re: aio_read2() and aio_write2()
- Reply: Alan Somers : "Re: aio_read2() and aio_write2()"
- In reply to: Alan Somers : "Re: aio_read2() and aio_write2()"
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Date: Sun, 14 Jan 2024 17:30:26 UTC
Em dom., 14 de jan. de 2024 às 14:13, Alan Somers <asomers@freebsd.org> escreveu: > The problem is that this flag would be almost impossible to use > correctly for the intended use cases of POSIX AIO. Your application > is actually pretty unusual in that it only has one operation in-flight > at a time. I think it would be better to use the lseek solution > rather than add a footgun to POSIX AIO. There are two things here: Boost.Asio, and applications built on top of Boost.Asio. I can't speak for other applications built on top of Boost.Asio. With that in mind, let me proceed. There is nothing unusual about my application. I just built an execution context that implements the green threading model. That's nothing unusual about that. NodeJS, Python's asyncio, Rust's asyncio, Golang, luvit, and so on and so on. All these frameworks just mimic interfaces from the blocking world (e.g. two threads doing a blocking read() on two different files become two fibers doing a read() within the same thread). If anything, the whole world is moving to this model after NodeJS proved its usefulness. So what's unusual about that? To clarify: I don't have a single in-flight operation at a time. The same thread dispatches IO requests for different streams (sockets and files). AIO is not only useful for batching operations (on the same file). AIO is also useful for a batch of IO operations on different files. File IO is always “ready” and the readiness model doesn't work for files. On Linux, I can just use io_uring (proactor/completion model) for everything (as in it won't prevent me from skipping an explicit offset). Same with Windows (IOCP). What is special about FreeBSD here? POSIX AIO by itself is useless to me. It's only useful to me with BSD extensions (SIGEV_KEVENT for kqueue integration). I don't see a reason why it can't have another small extension that is pretty much non-invasive. -- Vinícius dos Santos Oliveira https://vinipsmaker.github.io/