We avoid the problem by using poll(2).
On systems without poll(2) (older bsd-ish systems, and win32), we emulate
poll(2) using select(2) and check for valid descriptors before attempting
to access them via the descriptor sets.
If an out-of-range descriptor is detected, an E_WARNING is raised suggesting
that PHP should be recompiled with a larger FD_SETSIZE (and also with a
suggested value).
Most uses of select(2) in the source are to poll a single descriptor, so
a couple of handy wrapper functions have been added to make this easier.
A configure option --enable-fd-setsize has been added to both the unix and
win32 builds; on unix we default to 16384 and on windows we default to 256.
Windows FD_SETSIZE imposes a limit on the maximum number of descriptors that
can be select()ed at once, whereas the unix FD_SETSIZE limit is based on the
highest numbered descriptor; 256 should be plenty for PHP scripts under windows
(the default OS setting is 64).
The win32 specific parts are untested; will do that now.
using the default socket timeout of 60 seconds before returning the socket
to the calling script. The reason they were using that value is that the
same code is used for feof(), so the fix is allowing the caller to
indicate the timeout value for liveness checks.
A possible remaining issue now is that 0 second timeout[1] for pfsockopen
is possibly too short; it's impossible to specify a sane value for all
possible uses, so maybe we need a stream context or an .ini option to
control this, or maybe use the timeout value that was passed to
pfsockopen().
# [1] by timeout, I mean the time that PHP will wait for data on a
# persistent socket before deciding if a new connection should be made;
# NOT the timeout while waiting for a new connection to be established.
. stream_socket_client() - similar to fsockopen(), but more powerful.
. stream_socket_server() - Creates a server socket.
. stream_socket_accept() - Accept a client connection.
. stream_socket_get_name() - Get local or remote name of socket.
Tidy up some leaks and debug printfs.
Move more streams functions into streamsfuncs.c and streamsfuncs.h.
Main Changes:
- Implement a socket transport layer for use by all code that needs to open
some kind of "special" socket for network or IPC.
- Extensions can register (and override) transports.
- Implement ftruncate() on streams via the ioctl-alike option interface.
- Implement mmap() on streams via the ioctl-alike option interface.
- Implement generic crypto API via the ioctl-alike option interface.
(currently only supports OpenSSL, but could support other SSL toolkits,
and other crypto transport protocols).
Impact:
- tcp sockets can be overloaded by the openssl capable sockets at runtime,
removing the link-time requirement for ssl:// and https:// sockets and
streams.
- checking stream types using PHP_STREAM_IS_SOCKET is deprecated, since
there are now a range of possible socket-type streams.
Working towards:
- socket servers using the new transport layer
- mmap support under win32
- Cleaner code.
# I will be updating the win32 build to add the new files shortly
# after this commit.
