Merge assorted fixes from 3.2

This commit is contained in:
Antoine Pitrou 2011-12-05 01:47:40 +01:00
commit 3731142e19
1 changed files with 17 additions and 19 deletions

View File

@ -60,11 +60,10 @@ Creating a Socket
Roughly speaking, when you clicked on the link that brought you to this page,
your browser did something like the following::
#create an INET, STREAMing socket
# create an INET, STREAMing socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#now connect to the web server on port 80
# - the normal http port
s.connect(("www.mcmillan-inc.com", 80))
# now connect to the web server on port 80 - the normal http port
s.connect(("www.python.org", 80))
When the ``connect`` completes, the socket ``s`` can be used to send
in a request for the text of the page. The same socket will read the
@ -75,13 +74,11 @@ exchanges).
What happens in the web server is a bit more complex. First, the web server
creates a "server socket"::
#create an INET, STREAMing socket
serversocket = socket.socket(
socket.AF_INET, socket.SOCK_STREAM)
#bind the socket to a public host,
# and a well-known port
# create an INET, STREAMing socket
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind the socket to a public host, and a well-known port
serversocket.bind((socket.gethostname(), 80))
#become a server socket
# become a server socket
serversocket.listen(5)
A couple things to notice: we used ``socket.gethostname()`` so that the socket
@ -101,10 +98,10 @@ Now that we have a "server" socket, listening on port 80, we can enter the
mainloop of the web server::
while True:
#accept connections from outside
# accept connections from outside
(clientsocket, address) = serversocket.accept()
#now do something with the clientsocket
#in this case, we'll pretend this is a threaded server
# now do something with the clientsocket
# in this case, we'll pretend this is a threaded server
ct = client_thread(clientsocket)
ct.run()
@ -126,12 +123,13 @@ IPC
---
If you need fast IPC between two processes on one machine, you should look into
whatever form of shared memory the platform offers. A simple protocol based
around shared memory and locks or semaphores is by far the fastest technique.
pipes or shared memory. If you do decide to use AF_INET sockets, bind the
"server" socket to ``'localhost'``. On most platforms, this will take a
shortcut around a couple of layers of network code and be quite a bit faster.
If you do decide to use sockets, bind the "server" socket to ``'localhost'``. On
most platforms, this will take a shortcut around a couple of layers of network
code and be quite a bit faster.
.. seealso::
The :mod:`multiprocessing` integrates cross-platform IPC into a higher-level
API.
Using a Socket
@ -300,7 +298,7 @@ When Sockets Die
Probably the worst thing about using blocking sockets is what happens when the
other side comes down hard (without doing a ``close``). Your socket is likely to
hang. SOCKSTREAM is a reliable protocol, and it will wait a long, long time
hang. TCP is a reliable protocol, and it will wait a long, long time
before giving up on a connection. If you're using threads, the entire thread is
essentially dead. There's not much you can do about it. As long as you aren't
doing something dumb, like holding a lock while doing a blocking read, the