diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/howto/sockets.rst | 34 | ||||
| -rw-r--r-- | Doc/library/socket.rst | 14 |
2 files changed, 8 insertions, 40 deletions
diff --git a/Doc/howto/sockets.rst b/Doc/howto/sockets.rst index 2416807..324ea0a 100644 --- a/Doc/howto/sockets.rst +++ b/Doc/howto/sockets.rst @@ -371,12 +371,6 @@ have created a new socket to ``connect`` to someone else, put it in the potential_writers list. If it shows up in the writable list, you have a decent chance that it has connected. -One very nasty problem with ``select``: if somewhere in those input lists of -sockets is one which has died a nasty death, the ``select`` will fail. You then -need to loop through every single damn socket in all those lists and do a -``select([sock],[],[],0)`` until you find the bad one. That timeout of 0 means -it won't take long, but it's ugly. - Actually, ``select`` can be handy even with blocking sockets. It's one way of determining whether you will block - the socket returns as readable when there's something in the buffers. However, this still doesn't help with the problem of @@ -386,32 +380,6 @@ determining whether the other end is done, or just busy with something else. files. Don't try this on Windows. On Windows, ``select`` works with sockets only. Also note that in C, many of the more advanced socket options are done differently on Windows. In fact, on Windows I usually use threads (which work -very, very well) with my sockets. Face it, if you want any kind of performance, -your code will look very different on Windows than on Unix. - - -Performance ------------ +very, very well) with my sockets. -There's no question that the fastest sockets code uses non-blocking sockets and -select to multiplex them. You can put together something that will saturate a -LAN connection without putting any strain on the CPU. The trouble is that an app -written this way can't do much of anything else - it needs to be ready to -shuffle bytes around at all times. - -Assuming that your app is actually supposed to do something more than that, -threading is the optimal solution, (and using non-blocking sockets will be -faster than using blocking sockets). Unfortunately, threading support in Unixes -varies both in API and quality. So the normal Unix solution is to fork a -subprocess to deal with each connection. The overhead for this is significant -(and don't do this on Windows - the overhead of process creation is enormous -there). It also means that unless each subprocess is completely independent, -you'll need to use another form of IPC, say a pipe, or shared memory and -semaphores, to communicate between the parent and child processes. - -Finally, remember that even though blocking sockets are somewhat slower than -non-blocking, in many cases they are the "right" solution. After all, if your -app is driven by the data it receives over a socket, there's not much sense in -complicating the logic just so your app can wait on ``select`` instead of -``recv``. diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst index 7ce7705..afc674c 100644 --- a/Doc/library/socket.rst +++ b/Doc/library/socket.rst @@ -538,9 +538,9 @@ The module :mod:`socket` exports the following constants and functions: .. function:: if_nameindex() - Returns a list of network interface information - (index, name as a string) tuples. - :exc:`socket.error` if the system call fails for any reason. + Return a list of network interface information + (index int, name string) tuples. + :exc:`socket.error` if the system call fails. Availability: Unix. @@ -549,8 +549,8 @@ The module :mod:`socket` exports the following constants and functions: .. function:: if_nametoindex(if_name) - Returns a network interface index number corresponding to an - interface name string. + Return a network interface index number corresponding to an + interface name. :exc:`socket.error` if no interface with the given name exists. Availability: Unix. @@ -560,8 +560,8 @@ The module :mod:`socket` exports the following constants and functions: .. function:: if_indextoname(if_index) - Returns a network interface name string corresponding to a - interface index. + Return a network interface name corresponding to a + interface index number. :exc:`socket.error` if no interface with the given index exists. Availability: Unix. |