mhd_atomic_counter.c (3241B)
1 /* SPDX-License-Identifier: LGPL-2.1-or-later OR (GPL-2.0-or-later WITH eCos-exception-2.0) */ 2 /* 3 This file is part of GNU libmicrohttpd. 4 Copyright (C) 2024-2025 Evgeny Grin (Karlson2k) 5 6 GNU libmicrohttpd 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 GNU libmicrohttpd 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 Alternatively, you can redistribute GNU libmicrohttpd and/or 17 modify it under the terms of the GNU General Public License as 18 published by the Free Software Foundation; either version 2 of 19 the License, or (at your option) any later version, together 20 with the eCos exception, as follows: 21 22 As a special exception, if other files instantiate templates or 23 use macros or inline functions from this file, or you compile this 24 file and link it with other works to produce a work based on this 25 file, this file does not by itself cause the resulting work to be 26 covered by the GNU General Public License. However the source code 27 for this file must still be made available in accordance with 28 section (3) of the GNU General Public License v2. 29 30 This exception does not invalidate any other reasons why a work 31 based on this file might be covered by the GNU General Public 32 License. 33 34 You should have received copies of the GNU Lesser General Public 35 License and the GNU General Public License along with this library; 36 if not, see <https://www.gnu.org/licenses/>. 37 */ 38 39 /** 40 * @file src/mhd2/mhd_atomic_counter.c 41 * @brief The definition of the atomic counter functions 42 * @author Karlson2k (Evgeny Grin) 43 */ 44 45 #include "mhd_sys_options.h" 46 47 #include "mhd_atomic_counter.h" 48 49 #if defined(mhd_ATOMIC_BY_LOCKS) 50 51 #include "mhd_assert.h" 52 53 MHD_INTERNAL mhd_ATOMIC_COUNTER_TYPE 54 mhd_atomic_counter_get_inc_wrap (struct mhd_AtomicCounter *pcnt) 55 { 56 mhd_ATOMIC_COUNTER_TYPE ret; 57 58 mhd_mutex_lock_chk (&(pcnt->lock)); 59 ret = pcnt->count++; 60 mhd_mutex_unlock_chk (&(pcnt->lock)); 61 62 return ret; 63 } 64 65 66 #ifndef NDEBUG 67 68 MHD_INTERNAL mhd_ATOMIC_COUNTER_TYPE 69 mhd_atomic_counter_get_inc (struct mhd_AtomicCounter *pcnt) 70 { 71 const mhd_ATOMIC_COUNTER_TYPE ret = mhd_atomic_counter_get_inc_wrap (pcnt); 72 73 mhd_assert (mhd_ATOMIC_COUNTER_MAX != ret); /* check for overflow */ 74 75 return ret; 76 } 77 78 79 #endif /* ! NDEBUG */ 80 81 82 MHD_INTERNAL mhd_ATOMIC_COUNTER_TYPE 83 mhd_atomic_counter_get_dec (struct mhd_AtomicCounter *pcnt) 84 { 85 mhd_ATOMIC_COUNTER_TYPE ret; 86 87 mhd_mutex_lock_chk (&(pcnt->lock)); 88 ret = pcnt->count--; 89 mhd_mutex_unlock_chk (&(pcnt->lock)); 90 91 mhd_assert (mhd_ATOMIC_COUNTER_MAX != ret); /* check for underflow */ 92 93 return ret; 94 } 95 96 97 MHD_INTERNAL mhd_ATOMIC_COUNTER_TYPE 98 mhd_atomic_counter_get (struct mhd_AtomicCounter *pcnt) 99 { 100 mhd_ATOMIC_COUNTER_TYPE ret; 101 102 mhd_mutex_lock_chk (&(pcnt->lock)); 103 ret = pcnt->count; 104 mhd_mutex_unlock_chk (&(pcnt->lock)); 105 106 return ret; 107 } 108 109 110 #endif /* mhd_ATOMIC_BY_LOCKS */