1 /* Handle real-time signal allocation. 2 Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, see 18 <http://www.gnu.org/licenses/>. */ 19 20 #include <features.h> 21 #include <signal.h> 22 #include <sys/syscall.h> 23 24 /* Only enable rt signals when it is supported at compile time */ 25 #ifndef __NR_rt_sigaction 26 /* In these variables we keep track of the used variables. If the 27 platform does not support any real-time signals we will define the 28 values to some unreasonable value which will signal failing of all 29 the functions below. */ 30 static int current_rtmin = -1; 31 static int current_rtmax = -1; 32 #else 33 # ifdef __UCLIBC_HAS_THREADS_NATIVE__ 34 static int current_rtmin = __SIGRTMIN + 2; 35 # elif defined __UCLIBC_HAS_THREADS__ && !defined __UCLIBC_HAS_LINUXTHREADS__ 36 /* psm: might be good for LT old as well, do not want to break it for now */ 37 /* Sanity check */ 38 # if !defined __SIGRTMIN || (__SIGRTMAX - __SIGRTMIN) < 3 39 # error "This must not happen" 40 # endif 41 static int current_rtmin = __SIGRTMIN + 3; 42 # else 43 static int current_rtmin = __SIGRTMIN; 44 # endif 45 static int current_rtmax = __SIGRTMAX; 46 #endif 47 48 /* Return number of available real-time signal with highest priority. */ __libc_current_sigrtmin(void)49int __libc_current_sigrtmin (void) 50 { 51 return current_rtmin; 52 } 53 54 /* Return number of available real-time signal with lowest priority. */ __libc_current_sigrtmax(void)55int __libc_current_sigrtmax (void) 56 { 57 return current_rtmax; 58 } 59 60 #if 0 61 /* Allocate real-time signal with highest/lowest available 62 priority. Please note that we don't use a lock since we assume 63 this function to be called at program start. */ 64 int __libc_allocate_rtsig (int high); 65 int __libc_allocate_rtsig (int high) 66 { 67 if (current_rtmin == -1 || current_rtmin > current_rtmax) 68 /* We don't have anymore signal available. */ 69 return -1; 70 71 return high ? current_rtmin++ : current_rtmax--; 72 } 73 #endif 74