1 /* POSIX once-only control. 2 Copyright (C) 2019-2021 Free Software Foundation, Inc. 3 4 This file is free software: you can redistribute it and/or modify 5 it under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 This file is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* Written by Bruno Haible <bruno@clisp.org>, 2019. */ 18 19 #include <config.h> 20 21 /* Specification. */ 22 #include <pthread.h> 23 24 #if (defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS 25 # include "windows-once.h" 26 #endif 27 28 #if (defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS 29 /* Use Windows threads. */ 30 31 int 32 pthread_once (pthread_once_t *once_control, void (*initfunction) (void)) /* */ 33 { 34 glwthread_once (once_control, initfunction); 35 return 0; 36 } 37 38 #elif HAVE_PTHREAD_H 39 /* Provide workarounds for POSIX threads. */ 40 41 #else 42 /* Provide a dummy implementation for single-threaded applications. */ 43 44 int 45 pthread_once (pthread_once_t *once_control, void (*initfunction) (void)) /* */ 46 { 47 if (*once_control == 0) 48 { 49 *once_control = ~ 0; 50 initfunction (); 51 } 52 return 0; 53 } 54 55 #endif