| 1 | /* Handle real-time signal allocation. Generic version. |
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| 2 | Copyright (C) 1997-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <signal.h> |
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| 20 | #include <internal-signals.h> |
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| 21 | |
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| 22 | /* In these variables we keep track of the used variables. If the |
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| 23 | platform does not support any real-time signals we will define the |
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| 24 | values to some unreasonable value which will signal failing of all |
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| 25 | the functions below. */ |
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| 26 | #ifdef __SIGRTMIN |
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| 27 | static int current_rtmin = __SIGRTMIN + RESERVED_SIGRT; |
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| 28 | static int current_rtmax = __SIGRTMAX; |
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| 29 | #endif |
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| 30 | |
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| 31 | /* Return number of available real-time signal with highest priority. */ |
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| 32 | int |
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| 33 | __libc_current_sigrtmin (void) |
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| 34 | { |
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| 35 | #ifdef __SIGRTMIN |
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| 36 | return current_rtmin; |
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| 37 | #else |
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| 38 | return -1; |
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| 39 | #endif |
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| 40 | } |
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| 41 | libc_hidden_def (__libc_current_sigrtmin) |
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| 42 | |
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| 43 | /* Return number of available real-time signal with lowest priority. */ |
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| 44 | int |
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| 45 | __libc_current_sigrtmax (void) |
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| 46 | { |
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| 47 | #ifdef __SIGRTMIN |
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| 48 | return current_rtmax; |
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| 49 | #else |
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| 50 | return -1; |
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| 51 | #endif |
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| 52 | } |
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| 53 | libc_hidden_def (__libc_current_sigrtmax) |
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| 54 | |
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| 55 | /* Allocate real-time signal with highest/lowest available |
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| 56 | priority. Please note that we don't use a lock since we assume |
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| 57 | this function to be called at program start. */ |
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| 58 | int |
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| 59 | __libc_allocate_rtsig (int high) |
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| 60 | { |
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| 61 | #ifndef __SIGRTMIN |
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| 62 | return -1; |
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| 63 | #else |
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| 64 | if (current_rtmin == -1 || current_rtmin > current_rtmax) |
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| 65 | /* We don't have any more signals available. */ |
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| 66 | return -1; |
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| 67 | |
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| 68 | return high ? current_rtmin++ : current_rtmax--; |
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| 69 | #endif |
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| 70 | } |
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| 71 | |
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