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72 lines
2.2 KiB
C
72 lines
2.2 KiB
C
/* Linux select implementation.
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Copyright (C) 2017-2020 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 <sys/time.h>
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#include <sys/types.h>
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#include <sys/select.h>
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#include <errno.h>
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#include <sysdep-cancel.h>
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/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
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readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
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(if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
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after waiting the interval specified therein. Returns the number of ready
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descriptors, or -1 for errors. */
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#ifdef __NR__newselect
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# undef __NR_select
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# define __NR_select __NR__newselect
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#endif
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int
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__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
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struct timeval *timeout)
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{
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#ifdef __NR_select
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return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds,
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timeout);
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#else
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int result;
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struct timespec ts, *tsp = NULL;
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if (timeout)
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{
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TIMEVAL_TO_TIMESPEC (timeout, &ts);
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tsp = &ts;
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}
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result = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, tsp,
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NULL);
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if (timeout)
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{
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/* Linux by default will update the timeout after a pselect6 syscall
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(though the pselect() glibc call suppresses this behavior).
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Since select() on Linux has the same behavior as the pselect6
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syscall, we update the timeout here. */
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TIMESPEC_TO_TIMEVAL (timeout, &ts);
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}
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return result;
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#endif
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}
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libc_hidden_def (__select)
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weak_alias (__select, select)
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weak_alias (__select, __libc_select)
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