glibc/io/sys/poll.h
Martin Sebor 26492c0a14 Annotate additional APIs with GCC attribute access.
This change continues the improvements to compile-time out of bounds
checking by decorating more APIs with either attribute access, or by
explicitly providing the array bound in APIs such as tmpnam() that
expect arrays of some minimum size as arguments.  (The latter feature
is new in GCC 11.)

The only effects of the attribute and/or the array bound is to check
and diagnose calls to the functions that fail to provide a sufficient
number of elements, and the definitions of the functions that access
elements outside the specified bounds.  (There is no interplay with
_FORTIFY_SOURCE here yet.)

Tested with GCC 7 through 11 on x86_64-linux.
2021-05-06 11:01:05 -06:00

80 lines
2.6 KiB
C

/* Compatibility definitions for System V `poll' interface.
Copyright (C) 1994-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _SYS_POLL_H
#define _SYS_POLL_H 1
#include <features.h>
/* Get the platform dependent bits of `poll'. */
#include <bits/poll.h>
#ifdef __USE_GNU
# include <bits/types/__sigset_t.h>
# include <bits/types/struct_timespec.h>
#endif
/* Type used for the number of file descriptors. */
typedef unsigned long int nfds_t;
/* Data structure describing a polling request. */
struct pollfd
{
int fd; /* File descriptor to poll. */
short int events; /* Types of events poller cares about. */
short int revents; /* Types of events that actually occurred. */
};
__BEGIN_DECLS
/* Poll the file descriptors described by the NFDS structures starting at
FDS. If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
an event to occur; if TIMEOUT is -1, block until an event occurs.
Returns the number of file descriptors with events, zero if timed out,
or -1 for errors.
This function is a cancellation point and therefore not marked with
__THROW. */
extern int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
__attr_access ((__write_only__, 1, 2));
#ifdef __USE_GNU
/* Like poll, but before waiting the threads signal mask is replaced
with that specified in the fourth parameter. For better usability,
the timeout value is specified using a TIMESPEC object.
This function is a cancellation point and therefore not marked with
__THROW. */
extern int ppoll (struct pollfd *__fds, nfds_t __nfds,
const struct timespec *__timeout,
const __sigset_t *__ss)
__attr_access ((__write_only__, 1, 2));
#endif
__END_DECLS
/* Define some inlines helping to catch common problems. */
#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
# include <bits/poll2.h>
#endif
#endif /* sys/poll.h */