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    <p>You can share a socket between two (or more) processes in Linux and even Windows.</p> <p>Under Linux (Or POSIX type OS), using <code>fork()</code> will cause the forked child to have copies of all the parent's file descriptors. Any that it does not close will continue to be shared, and (for example with a TCP listening socket) can be used to <code>accept()</code> new sockets for clients. This is how many servers, including Apache in most cases, work.</p> <p>On Windows the same thing is basically true, except there is no <code>fork()</code> system call so the parent process will need to use <code>CreateProcess</code> or something to create a child process (which can of course use the same executable) and needs to pass it an inheritable handle.</p> <p>Making a listening socket an inheritable handle is not a completely trivial activity but not too tricky either. <code>DuplicateHandle()</code> needs to be used to create a duplicate handle (still in the parent process however), which will have the inheritable flag set on it. Then you can give that handle in the <code>STARTUPINFO</code> structure to the child process in CreateProcess as a <code>STDIN</code>, <code>OUT</code> or <code>ERR</code> handle (assuming you didn't want to use it for anything else).</p> <p>EDIT:</p> <p>Reading the MDSN library , it appears that <code>WSADuplicateSocket</code> is a more robust or correct mechanism of doing this; it is still nontrivial because the parent/child processes need to work out which handle needs to be duplicated by some IPC mechanism (although this could be as simple as a file in the filesystem)</p> <p>CLARIFICATION:</p> <p>In answer to the OP's original question, no, multiple processes cannot <code>bind()</code>; just the original parent process would call <code>bind()</code>, <code>listen()</code> etc, the child processes would just process requests by <code>accept()</code>, <code>send()</code>, <code>recv()</code> etc.</p>
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    1. POIs there a way for multiple processes to share a listening socket?
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    1. USMarkR
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    1. POIs there a way for multiple processes to share a listening socket?
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    1. COMultiple processes can bind by specifying the SocketOptionName.ReuseAddress socket option.
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      1. USsipwiz
    2. COBut what's the point? Processes are more heavyweight than threads anyway.
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      1. USAnton Tykhyy
    3. COExcellent, nice and simple. I didn't think of inheritable handles. Will try it and report back!
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      1. USDaniel Earwicker
 

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