/* Copyright (C) 1996-1998,2001,2002,2003,2006 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. 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 <features.h> #ifdef __USE_XOPEN2K #include <sys/syscall.h> #include <sys/select.h> #include <sys/time.h> #include <signal.h> #include <cancel.h> static int __NC(pselect)(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timespec *timeout, const sigset_t *sigmask) { #ifdef __NR_pselect6 /* The Linux kernel can in some situations update the timeout value. * We do not want that so use a local variable. */ struct timespec _ts; if (timeout != NULL) { _ts = *timeout; timeout = &_ts; } /* Note: the system call expects 7 values but on most architectures we can only pass in 6 directly. If there is an architecture with support for more parameters a new version of this file needs to be created. */ struct { __kernel_ulong_t ss; __kernel_size_t ss_len; } data; if (sigmask != NULL) { data.ss = (__kernel_ulong_t) sigmask; data.ss_len = __SYSCALL_SIGSET_T_SIZE; sigmask = (void *)&data; } return INLINE_SYSCALL(pselect6, 6, nfds, readfds, writefds, exceptfds, timeout, sigmask); #else struct timeval tval; int retval; sigset_t savemask; /* Change nanosecond number to microseconds. This might mean losing precision and therefore the `pselect` should be available. But for now it is hardly found. */ if (timeout != NULL) TIMESPEC_TO_TIMEVAL (&tval, timeout); /* The setting and restoring of the signal mask and the select call should be an atomic operation. This can't be done without kernel help. */ if (sigmask != NULL) sigprocmask (SIG_SETMASK, sigmask, &savemask); /* The comment below does not apply on uClibc, since we use __select_nocancel */ /* Note the pselect() is a cancellation point. But since we call select() which itself is a cancellation point we do not have to do anything here. */ retval = __NC(select)(nfds, readfds, writefds, exceptfds, timeout != NULL ? &tval : NULL); if (sigmask != NULL) sigprocmask (SIG_SETMASK, &savemask, NULL); return retval; #endif } CANCELLABLE_SYSCALL(int, pselect, (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timespec *timeout, const sigset_t *sigmask), (nfds, readfds, writefds, exceptfds, timeout, sigmask)) #endif