From 93ab5fa1916d745aa817ed47297725826f4ec62c Mon Sep 17 00:00:00 2001 From: Anthony Baxter Date: Tue, 11 Jul 2006 02:04:09 +0000 Subject: [PATCH] #1494314: Fix a regression with high-numbered sockets in 2.4.3. This means that select() on sockets > FD_SETSIZE (typically 1024) work again. The patch makes sockets use poll() internally where available. --- Misc/NEWS | 4 +++ Modules/_ssl.c | 29 +++++++++++++++++++- Modules/socketmodule.c | 60 +++++++++++++++++++++++++++++++----------- 3 files changed, 76 insertions(+), 17 deletions(-) diff --git a/Misc/NEWS b/Misc/NEWS index fd6c17ce299..080f4a7f6f9 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -105,6 +105,10 @@ Library Extension Modules ----------------- +- #1494314: Fix a regression with high-numbered sockets in 2.4.3. This + means that select() on sockets > FD_SETSIZE (typically 1024) work again. + The patch makes sockets use poll() internally where available. + - Assigning None to pointer type fields in ctypes structures possible overwrote the wrong fields, this is fixed now. diff --git a/Modules/_ssl.c b/Modules/_ssl.c index f49391d7f00..3b91b24515f 100644 --- a/Modules/_ssl.c +++ b/Modules/_ssl.c @@ -26,6 +26,12 @@ enum py_ssl_error { /* Include symbols from _socket module */ #include "socketmodule.h" +#if defined(HAVE_POLL_H) +#include +#elif defined(HAVE_SYS_POLL_H) +#include +#endif + /* Include OpenSSL header files */ #include "openssl/rsa.h" #include "openssl/crypto.h" @@ -351,7 +357,7 @@ static void PySSL_dealloc(PySSLObject *self) PyObject_Del(self); } -/* If the socket has a timeout, do a select() on the socket. +/* If the socket has a timeout, do a select()/poll() on the socket. The argument writing indicates the direction. Returns one of the possibilities in the timeout_state enum (above). */ @@ -373,6 +379,26 @@ check_socket_and_wait_for_timeout(PySocketSockObject *s, int writing) if (s->sock_fd < 0) return SOCKET_HAS_BEEN_CLOSED; + /* Prefer poll, if available, since you can poll() any fd + * which can't be done with select(). */ +#ifdef HAVE_POLL + { + struct pollfd pollfd; + int timeout; + + pollfd.fd = s->sock_fd; + pollfd.events = writing ? POLLOUT : POLLIN; + + /* s->sock_timeout is in seconds, timeout in ms */ + timeout = (int)(s->sock_timeout * 1000 + 0.5); + Py_BEGIN_ALLOW_THREADS + rc = poll(&pollfd, 1, timeout); + Py_END_ALLOW_THREADS + + goto normal_return; + } +#endif + /* Guard against socket too large for select*/ #ifndef Py_SOCKET_FD_CAN_BE_GE_FD_SETSIZE if (s->sock_fd >= FD_SETSIZE) @@ -393,6 +419,7 @@ check_socket_and_wait_for_timeout(PySocketSockObject *s, int writing) rc = select(s->sock_fd+1, &fds, NULL, NULL, &tv); Py_END_ALLOW_THREADS +normal_return: /* Return SOCKET_TIMED_OUT on timeout, SOCKET_OPERATION_OK otherwise (when we are able to write or when there's something to read) */ return rc == 0 ? SOCKET_HAS_TIMED_OUT : SOCKET_OPERATION_OK; diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c index 11b184ed0a5..d07ce350a7c 100644 --- a/Modules/socketmodule.c +++ b/Modules/socketmodule.c @@ -411,14 +411,24 @@ static int taskwindow; there has to be a circular reference. */ static PyTypeObject sock_type; -/* Can we call select() with this socket without a buffer overrun? */ +#if defined(HAVE_POLL_H) +#include +#elif defined(HAVE_SYS_POLL_H) +#include +#endif + #ifdef Py_SOCKET_FD_CAN_BE_GE_FD_SETSIZE /* Platform can select file descriptors beyond FD_SETSIZE */ #define IS_SELECTABLE(s) 1 +#elif defined(HAVE_POLL) +/* Instead of select(), we'll use poll() since poll() works on any fd. */ +#define IS_SELECTABLE(s) 1 +/* Can we call select() with this socket without a buffer overrun? */ #else /* POSIX says selecting file descriptors beyond FD_SETSIZE - has undefined behaviour. */ -#define IS_SELECTABLE(s) ((s)->sock_fd < FD_SETSIZE) + has undefined behaviour. If there's no timeout left, we don't have to + call select, so it's a safe, little white lie. */ +#define IS_SELECTABLE(s) ((s)->sock_fd < FD_SETSIZE || s->sock_timeout <= 0.0) #endif static PyObject* @@ -686,7 +696,7 @@ internal_setblocking(PySocketSockObject *s, int block) return 1; } -/* Do a select() on the socket, if necessary (sock_timeout > 0). +/* Do a select()/poll() on the socket, if necessary (sock_timeout > 0). The argument writing indicates the direction. This does not raise an exception; we'll let our caller do that after they've reacquired the interpreter lock. @@ -694,8 +704,6 @@ internal_setblocking(PySocketSockObject *s, int block) static int internal_select(PySocketSockObject *s, int writing) { - fd_set fds; - struct timeval tv; int n; /* Nothing to do unless we're in timeout mode (not non-blocking) */ @@ -706,17 +714,37 @@ internal_select(PySocketSockObject *s, int writing) if (s->sock_fd < 0) return 0; - /* Construct the arguments to select */ - tv.tv_sec = (int)s->sock_timeout; - tv.tv_usec = (int)((s->sock_timeout - tv.tv_sec) * 1e6); - FD_ZERO(&fds); - FD_SET(s->sock_fd, &fds); + /* Prefer poll, if available, since you can poll() any fd + * which can't be done with select(). */ +#ifdef HAVE_POLL + { + struct pollfd pollfd; + int timeout; - /* See if the socket is ready */ - if (writing) - n = select(s->sock_fd+1, NULL, &fds, NULL, &tv); - else - n = select(s->sock_fd+1, &fds, NULL, NULL, &tv); + pollfd.fd = s->sock_fd; + pollfd.events = writing ? POLLOUT : POLLIN; + + /* s->sock_timeout is in seconds, timeout in ms */ + timeout = (int)(s->sock_timeout * 1000 + 0.5); + n = poll(&pollfd, 1, timeout); + } +#else + { + /* Construct the arguments to select */ + fd_set fds; + struct timeval tv; + tv.tv_sec = (int)s->sock_timeout; + tv.tv_usec = (int)((s->sock_timeout - tv.tv_sec) * 1e6); + FD_ZERO(&fds); + FD_SET(s->sock_fd, &fds); + + /* See if the socket is ready */ + if (writing) + n = select(s->sock_fd+1, NULL, &fds, NULL, &tv); + else + n = select(s->sock_fd+1, &fds, NULL, NULL, &tv); + } +#endif if (n == 0) return 1; return 0;