curl/lib/select.h
Mark Swaanenburg d293bf4a78
lib: don't compare fd to FD_SETSIZE when using poll
FD_SETSIZE is irrelevant when using poll. So ensuring that the file
descriptor is smaller than FD_SETSIZE in VALID_SOCK, can cause
multi_wait to ignore perfectly valid file descriptors and simply wait
for 1s to avoid hammering the CPU in a busy loop.

Fixes #7240
Closes #7241
2021-06-11 10:33:32 +02:00

123 lines
3.5 KiB
C

#ifndef HEADER_CURL_SELECT_H
#define HEADER_CURL_SELECT_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#ifdef HAVE_POLL_H
#include <poll.h>
#elif defined(HAVE_SYS_POLL_H)
#include <sys/poll.h>
#endif
/*
* Definition of pollfd struct and constants for platforms lacking them.
*/
#if !defined(HAVE_STRUCT_POLLFD) && \
!defined(HAVE_SYS_POLL_H) && \
!defined(HAVE_POLL_H) && \
!defined(POLLIN)
#define POLLIN 0x01
#define POLLPRI 0x02
#define POLLOUT 0x04
#define POLLERR 0x08
#define POLLHUP 0x10
#define POLLNVAL 0x20
struct pollfd
{
curl_socket_t fd;
short events;
short revents;
};
#endif
#ifndef POLLRDNORM
#define POLLRDNORM POLLIN
#endif
#ifndef POLLWRNORM
#define POLLWRNORM POLLOUT
#endif
#ifndef POLLRDBAND
#define POLLRDBAND POLLPRI
#endif
/* there are three CSELECT defines that are defined in the public header that
are exposed to users, but this *IN2 bit is only ever used internally and
therefore defined here */
#define CURL_CSELECT_IN2 (CURL_CSELECT_ERR << 1)
int Curl_socket_check(curl_socket_t readfd, curl_socket_t readfd2,
curl_socket_t writefd,
timediff_t timeout_ms);
#define SOCKET_READABLE(x,z) \
Curl_socket_check(x, CURL_SOCKET_BAD, CURL_SOCKET_BAD, z)
#define SOCKET_WRITABLE(x,z) \
Curl_socket_check(CURL_SOCKET_BAD, CURL_SOCKET_BAD, x, z)
int Curl_poll(struct pollfd ufds[], unsigned int nfds, timediff_t timeout_ms);
int Curl_wait_ms(timediff_t timeout_ms);
#ifdef TPF
int tpf_select_libcurl(int maxfds, fd_set* reads, fd_set* writes,
fd_set* excepts, struct timeval *tv);
#endif
/* TPF sockets are not in range [0..FD_SETSIZE-1], which
unfortunately makes it impossible for us to easily check if they're valid
With Winsock the valid range is [0..INVALID_SOCKET-1] according to
https://docs.microsoft.com/en-us/windows/win32/winsock/socket-data-type-2
*/
#if defined(TPF)
#define VALID_SOCK(x) 1
#define VERIFY_SOCK(x) Curl_nop_stmt
#elif defined(USE_WINSOCK)
#define VALID_SOCK(s) ((s) < INVALID_SOCKET)
#define VERIFY_SOCK(x) do { \
if(!VALID_SOCK(x)) { \
SET_SOCKERRNO(WSAEINVAL); \
return -1; \
} \
} while(0)
#else
#ifdef HAVE_POLL_FINE
#define VALID_SOCK(s) ((s) >= 0) /* FD_SETSIZE is irrelevant for poll */
#else
#define VALID_SOCK(s) (((s) >= 0) && ((s) < FD_SETSIZE))
#endif
#define VERIFY_SOCK(x) do { \
if(!VALID_SOCK(x)) { \
SET_SOCKERRNO(EINVAL); \
return -1; \
} \
} while(0)
#endif
#endif /* HEADER_CURL_SELECT_H */