/* Synchronous I/O multiplexing. Linux/microblaze version. Copyright (C) 2019-2020 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 . */ #include #include #include #include #include #ifndef __ASSUME_PSELECT # define __pselect __pselect_syscall #endif /* If pselect is supported, just use the Linux generic implementation. */ #include #ifndef __ASSUME_PSELECT # undef __pselect int __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timespec *timeout, const sigset_t *sigmask) { int ret = __pselect_syscall (nfds, readfds, writefds, exceptfds, timeout, sigmask); if (ret >= 0 || errno != ENOSYS) return ret; /* The fallback uses 'select' which shows the race condition regarding signal mask set/restore, requires two additional syscalls, and has a worse timeout precision (microseconds instead of nanoseconds). */ struct timeval tval, *ptval = NULL; if (timeout != NULL) { if (! valid_nanoseconds (timeout->tv_nsec)) { __set_errno (EINVAL); return -1; } TIMESPEC_TO_TIMEVAL (&tval, timeout); ptval = &tval; } sigset_t savemask; if (sigmask != NULL) __sigprocmask (SIG_SETMASK, sigmask, &savemask); /* select itself is a cancellation entrypoint. */ ret = __select (nfds, readfds, writefds, exceptfds, ptval); if (sigmask != NULL) __sigprocmask (SIG_SETMASK, &savemask, NULL); return ret; } weak_alias (__pselect, pselect) #endif