/* vi: set sw=4 ts=4: */ /* sigwait * * Copyright (C) 2006 by Steven J. Hill <sjhill@realitydiluted.com> * Copyright (C) 2003-2005 by Erik Andersen <andersen@uclibc.org> * * This program 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, write to the Free * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA * 02111-1307 USA. */ #include <errno.h> #include <signal.h> #include <string.h> #include <unistd.h> #ifdef __UCLIBC_HAS_THREADS_NATIVE__ # include <sysdep-cancel.h> # ifdef __NR_rt_sigtimedwait /* Return any pending signal or wait for one for the given time. */ static int do_sigwait(const sigset_t *set, int *sig) { int ret; # ifdef SIGCANCEL sigset_t tmpset; if (set != NULL && (__builtin_expect (__sigismember (set, SIGCANCEL), 0) # ifdef SIGSETXID || __builtin_expect (__sigismember (set, SIGSETXID), 0) # endif )) { /* Create a temporary mask without the bit for SIGCANCEL set. */ // We are not copying more than we have to. memcpy(&tmpset, set, _NSIG / 8); __sigdelset(&tmpset, SIGCANCEL); # ifdef SIGSETXID __sigdelset(&tmpset, SIGSETXID); # endif set = &tmpset; } # endif /* XXX The size argument hopefully will have to be changed to the real size of the user-level sigset_t. */ INTERNAL_SYSCALL_DECL(err); do ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, set, NULL, NULL, _NSIG / 8); while (INTERNAL_SYSCALL_ERROR_P (ret, err) && INTERNAL_SYSCALL_ERRNO (ret, err) == EINTR); if (! INTERNAL_SYSCALL_ERROR_P (ret, err)) { *sig = ret; ret = 0; } else ret = INTERNAL_SYSCALL_ERRNO (ret, err); return ret; } int sigwait (const sigset_t *set, int *sig) { if(SINGLE_THREAD_P) return do_sigwait(set, sig); int oldtype = LIBC_CANCEL_ASYNC(); int result = do_sigwait(set, sig); LIBC_CANCEL_RESET(oldtype); return result; } # else /* __NR_rt_sigtimedwait */ # error We must have rt_sigtimedwait defined!!! # endif #else /* __UCLIBC_HAS_THREADS_NATIVE__ */ # if defined __UCLIBC_HAS_REALTIME__ int sigwait (const sigset_t *set, int *sig) { int ret = 1; if ((ret = sigwaitinfo(set, NULL)) != -1) { *sig = ret; return 0; } return 1; } # else /* __UCLIBC_HAS_REALTIME__ */ /* variant without REALTIME extensions */ static smallint was_sig; /* obviously not thread-safe */ static void ignore_signal(int sig) { was_sig = sig; } int sigwait (const sigset_t *set, int *sig) { sigset_t tmp_mask; struct sigaction saved[NSIG]; struct sigaction action; int save_errno; int this; /* Prepare set. */ __sigfillset (&tmp_mask); /* Unblock all signals in the SET and register our nice handler. */ action.sa_handler = ignore_signal; action.sa_flags = 0; __sigfillset (&action.sa_mask); /* Block all signals for handler. */ /* Make sure we recognize error conditions by setting WAS_SIG to a value which does not describe a legal signal number. */ was_sig = -1; for (this = 1; this < NSIG; ++this) if (__sigismember (set, this)) { /* Unblock this signal. */ __sigdelset (&tmp_mask, this); /* Register temporary action handler. */ /* In Linux (as of 2.6.25), fails only if sig is SIGKILL or SIGSTOP */ /* (so, will it work correctly if set has, say, SIGSTOP?) */ if (sigaction (this, &action, &saved[this]) != 0) goto restore_handler; } /* Now we can wait for signals. */ sigsuspend (&tmp_mask); restore_handler: save_errno = errno; while (--this >= 1) if (__sigismember (set, this)) /* We ignore errors here since we must restore all handlers. */ sigaction (this, &saved[this], NULL); __set_errno (save_errno); /* Store the result and return. */ *sig = was_sig; return was_sig == -1 ? -1 : 0; } # endif /* __UCLIBC_HAS_REALTIME__ */ #endif /* __UCLIBC_HAS_THREADS_NATIVE__ */