| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Handle real-time signal allocation. Generic version. |
| 2 | Copyright (C) 1997-2015 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 <signal.h> |
| 21 | |
| 22 | /* Another sysdeps file can #define this and then #include this file. */ |
| 23 | #ifndef RESERVED_SIGRT |
| 24 | # define RESERVED_SIGRT 0 |
| 25 | #endif |
| 26 | |
| 27 | /* In these variables we keep track of the used variables. If the |
| 28 | platform does not support any real-time signals we will define the |
| 29 | values to some unreasonable value which will signal failing of all |
| 30 | the functions below. */ |
| 31 | #ifdef __SIGRTMIN |
| 32 | static int current_rtmin = __SIGRTMIN + RESERVED_SIGRT; |
| 33 | static int current_rtmax = __SIGRTMAX; |
| 34 | #endif |
| 35 | |
| 36 | /* Return number of available real-time signal with highest priority. */ |
| 37 | int |
| 38 | __libc_current_sigrtmin (void) |
| 39 | { |
| 40 | #ifdef __SIGRTMIN |
| 41 | return current_rtmin; |
| 42 | #else |
| 43 | return -1; |
| 44 | #endif |
| 45 | } |
| 46 | libc_hidden_def (__libc_current_sigrtmin) |
| 47 | strong_alias (__libc_current_sigrtmin, __libc_current_sigrtmin_private) |
| 48 | |
| 49 | /* Return number of available real-time signal with lowest priority. */ |
| 50 | int |
| 51 | __libc_current_sigrtmax (void) |
| 52 | { |
| 53 | #ifdef __SIGRTMIN |
| 54 | return current_rtmax; |
| 55 | #else |
| 56 | return -1; |
| 57 | #endif |
| 58 | } |
| 59 | libc_hidden_def (__libc_current_sigrtmax) |
| 60 | strong_alias (__libc_current_sigrtmax, __libc_current_sigrtmax_private) |
| 61 | |
| 62 | /* Allocate real-time signal with highest/lowest available |
| 63 | priority. Please note that we don't use a lock since we assume |
| 64 | this function to be called at program start. */ |
| 65 | int |
| 66 | __libc_allocate_rtsig (int high) |
| 67 | { |
| 68 | #ifndef __SIGRTMIN |
| 69 | return -1; |
| 70 | #else |
| 71 | if (current_rtmin == -1 || current_rtmin > current_rtmax) |
| 72 | /* We don't have any more signals available. */ |
| 73 | return -1; |
| 74 | |
| 75 | return high ? current_rtmin++ : current_rtmax--; |
| 76 | #endif |
| 77 | } |
| 78 | strong_alias (__libc_allocate_rtsig, __libc_allocate_rtsig_private) |