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74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
/* Synchronous I/O multiplexing. Linux/microblaze version.
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Copyright (C) 2019-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <signal.h>
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#include <time.h>
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#include <sys/poll.h>
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#include <sysdep-cancel.h>
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#ifndef __ASSUME_PSELECT
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# define __pselect __pselect_syscall
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#endif
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/* If pselect is supported, just use the Linux generic implementation. */
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#include <sysdeps/unix/sysv/linux/pselect.c>
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#ifndef __ASSUME_PSELECT
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# undef __pselect
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int
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__pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
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const struct timespec *timeout, const sigset_t *sigmask)
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{
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int ret = __pselect_syscall (nfds, readfds, writefds, exceptfds, timeout,
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sigmask);
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if (ret >= 0 || errno != ENOSYS)
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return ret;
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/* The fallback uses 'select' which shows the race condition regarding
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signal mask set/restore, requires two additional syscalls, and has
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a worse timeout precision (microseconds instead of nanoseconds). */
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struct timeval tval, *ptval = NULL;
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if (timeout != NULL)
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{
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if (! valid_nanoseconds (timeout->tv_nsec))
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{
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__set_errno (EINVAL);
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return -1;
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}
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TIMESPEC_TO_TIMEVAL (&tval, timeout);
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ptval = &tval;
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}
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sigset_t savemask;
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if (sigmask != NULL)
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__sigprocmask (SIG_SETMASK, sigmask, &savemask);
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/* select itself is a cancellation entrypoint. */
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ret = __select (nfds, readfds, writefds, exceptfds, ptval);
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if (sigmask != NULL)
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__sigprocmask (SIG_SETMASK, &savemask, NULL);
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return ret;
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}
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weak_alias (__pselect, pselect)
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#endif
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