Re: Non-blocking socket read on Windows

On Windows, you can use this ioctl call to make the socket non blocking:

ioctl($socket, 0x8004667e, $nonblocking);
[download]

update: $nonblocking = 1 => makes the socket non blocking, $nonblocking = 0 => makes the socket blocking.

Comment on Re: Non-blocking socket read on Windows Select or Download Code

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Re^2: Non-blocking socket read on Windows by spurperl (Priest) on Feb 13, 2006 at 17:53 UTC
This solution works admirably ! After setting the ioctl() command you're suggesting on my socket, I'm reading from it using sysread(), which behaves in a non-blocking way, returning the amount of bytes it has actually read. This overall works much faster than my looping approach, especially for longer messages. Although this is probably off-topic, it's curious how the "magic value" of 0x8004667E is created. The "macro" for non-blocking IO in ioctl() is FIONBIO, and its calculation is done thus: `IOC_IN = 0x80000000h; FIONBIO = IOC_IN + 4 * 65536 + ORD ('f') * 256 + 126;` [download] I wonder what is the rationale behind this ? Can someone explain how these things work ? Is it portable to just plunge the magic value in my code ?	[reply] [d/l]

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Re^2: Non-blocking socket read on Windows
by spurperl (Priest) on Feb 13, 2006 at 17:53 UTC

After setting the ioctl() command you're suggesting on my socket, I'm reading from it using sysread(), which behaves in a non-blocking way, returning the amount of bytes it has actually read. This overall works much faster than my looping approach, especially for longer messages.

Although this is probably off-topic, it's curious how the "magic value" of 0x8004667E is created. The "macro" for non-blocking IO in ioctl() is FIONBIO, and its calculation is done thus:

IOC_IN = 0x80000000h; 
FIONBIO = IOC_IN + 4 * 65536 + ORD ('f') * 256 + 126;
[download]

[reply]
[d/l]