diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/select.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/select.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/select.c b/sysdeps/unix/sysv/linux/select.c new file mode 100644 index 0000000..be4a456 --- /dev/null +++ b/sysdeps/unix/sysv/linux/select.c @@ -0,0 +1,71 @@ +/* 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) |