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-rw-r--r--sysdeps/unix/sysv/linux/select.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/select.c b/sysdeps/unix/sysv/linux/select.c
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+++ b/sysdeps/unix/sysv/linux/select.c
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+/* Linux select implementation.
+ Copyright (C) 2017 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/select.h>
+#include <errno.h>
+#include <sysdep-cancel.h>
+
+/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
+ readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
+ (if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
+ after waiting the interval specified therein. Returns the number of ready
+ descriptors, or -1 for errors. */
+
+#ifdef __NR__newselect
+# undef __NR_select
+# define __NR_select __NR__newselect
+#endif
+
+int
+__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+ struct timeval *timeout)
+{
+#ifdef __NR_select
+ return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds,
+ timeout);
+#else
+ int result;
+ struct timespec ts, *tsp = NULL;
+
+ if (timeout)
+ {
+ TIMEVAL_TO_TIMESPEC (timeout, &ts);
+ tsp = &ts;
+ }
+
+ result = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, tsp,
+ NULL);
+
+ if (timeout)
+ {
+ /* Linux by default will update the timeout after a pselect6 syscall
+ (though the pselect() glibc call suppresses this behavior).
+ Since select() on Linux has the same behavior as the pselect6
+ syscall, we update the timeout here. */
+ TIMESPEC_TO_TIMEVAL (timeout, &ts);
+ }
+
+ return result;
+#endif
+}
+libc_hidden_def (__select)
+
+weak_alias (__select, select)
+weak_alias (__select, __libc_select)