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A comment on Async file IO in Java is not truly async [Resource, Tech blog].

Re:Async file IO in Java is not truly async [Resource, Tech ... by bitcharmer on Monday January 08, 2024 @03:28PM (#38917647)
This has almost nothing to do with Java and there is nothing revealing in this blog post. Block device operations on Linux always went through layers of indirection. That's why things like page cache or writeback exist. You can always go O_DIRECT if you need the write to be truly synchronous.

If anything the author just discovered how IO works on Linux.

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Re:Async file IO in Java is not truly async [Resource, Tech ... by yxhuvud on Monday January 08, 2024 @03:46PM (#38917851)
Except that nowadays you can actually do async file IO using io_uring.
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Re:Async file IO in Java is not truly async [Resource, Tech ... by PaulDavisThe1st on Monday January 08, 2024 @05:18PM (#38919055)
O_DIRECT doesn't guarantee synchronous, it only skips the buffer cache.
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