Are there equivalents to pread on different platforms?

Question

I am writing a concurrent, persistent message queue in C++, which requires concurrent read access to a file without using memory mapped io. Short story is that several threa

Answer 1

With NIO, java.nio.channels.FileChannel has a read(ByteBuffer dst, long position) method, which internally uses pread.

Oh wait, your question is about C++, not Java. Well, I just looked at the JDK source code to see how it does it for Windows, but unfortunately on Windows it isn't atomic: it simply seeks, then reads, then seeks back.

For Unix platforms, the punchline is that pread is standard for any XSI-supporting (X/Open System Interface, apparently) operating system: http://www.opengroup.org/onlinepubs/009695399/functions/pread.html