Messages in this thread | | | From | "Joseph Seigh" <> | Subject | What does atomic_read actually do? | Date | Sat, 18 Dec 2004 11:23:37 -0500 |
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It doesn't do anything that would actually guarantee that the fetch from memory would be atomic as far as I can see, at least in the x86 version. The C standard has nothing to say about atomicity w.r.t. multithreading or multiprocessing. Is this a gcc compiler thing? If so, does gcc guarantee that it will fetch aligned ints with a single instruction on all platforms or just x86? And what's with volatile since if the C standard implies nothing about multithreading then it follows that volatile has no meaning with respect to multithreading either? Also a gcc thing? Are volatile semantics well defined enough that you can use it to make the compiler synchronize memory state as far as it is concerned?
Joe Seigh
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