Clarify the interaction between timeout/non-blocking mode, makefile

and fromfd.
This commit is contained in:
Guido van Rossum 2002-06-07 12:38:23 +00:00
parent 62a7f63a24
commit 715b861d94

View File

@ -284,7 +284,7 @@ checked --- subsequent operations on the object may fail if the file
descriptor is invalid. This function is rarely needed, but can be
used to get or set socket options on a socket passed to a program as
standard input or output (such as a server started by the \UNIX{} inet
daemon). The socket is assumed to be created in blocking mode without
daemon). The socket is assumed to be in blocking mode without
a timeout.
Availability: \UNIX.
\end{funcdesc}
@ -455,6 +455,7 @@ are described in \ref{bltin-file-objects}, ``File Objects.'')
The file object references a \cfunction{dup()}ped version of the
socket file descriptor, so the file object and socket object may be
closed or garbage-collected independently.
The socket should be in blocking mode.
\index{I/O control!buffering}The optional \var{mode}
and \var{bufsize} arguments are interpreted the same way as by the
built-in \function{file()} function; see ``Built-in Functions''
@ -546,6 +547,14 @@ previously set timeout. Setting the timeout to zero acts similarly
but is implemented different than setting the socket in non-blocking
mode (this could be considered a bug and may even be fixed).
Timeout mode internally sets the socket in non-blocking mode. The
blocking and timeout modes are shared between file descriptors and
socket objects that refer to the same network endpoint. A consequence
of this is that file objects returned by the \method{makefile()}
method should only be used when the socket is in blocking mode; in
timeout or non-blocking mode file operations that cannot be completed
immediately will fail.
\begin{methoddesc}[socket]{setsockopt}{level, optname, value}
Set the value of the given socket option (see the \UNIX{} manual page
\manpage{setsockopt}{2}). The needed symbolic constants are defined in