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.
. 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.
Arnaud Le Blanc