FileInputStream and FileOutputStream to the same file: Is a read() guaranteed to see all write()s that "happened before"?

Posted by user946850 on Stack Overflow See other posts from Stack Overflow or by user946850
Published on 2012-10-05T07:54:33Z Indexed on 2012/10/07 21:37 UTC
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java

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concurrency

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stream

I am using a file as a cache for big data. One thread writes to it sequentially, another thread reads it sequentially.

Can I be sure that all data that has been written (by write()) in one thread can be read() from another thread, assuming a proper "happens-before" relationship in terms of the Java memory model? Is this behavior documented?

EDIT: In my JDK, FileOutputSream does not override flush(), and OutputStream.flush() is empty. That's why I'm wondering...

EDIT^2: The streams in question are owned exclusively by a class that I have full control of. Each stream is guaranteed to be accesses by one thread only. My tests show that it works as expected, but I'm still wondering if this is guaranteed and documented.

See also this related discussion: http://chat.stackoverflow.com/rooms/17598/discussion-between-hussain-al-mutawa-and-user946850

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