1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2009 Hudson River Trading LLC 5 * Written by: John H. Baldwin <jhb@FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include "namespace.h" 31 #include <pthread.h> 32 #include "un-namespace.h" 33 #include "libc_private.h" 34 35 /* This implements pthread_once() for the single-threaded case. */ 36 static int 37 _libc_once(pthread_once_t *once_control, void (*init_routine)(void)) 38 { 39 40 if (once_control->state == PTHREAD_DONE_INIT) 41 return (0); 42 init_routine(); 43 once_control->state = PTHREAD_DONE_INIT; 44 return (0); 45 } 46 47 /* 48 * This is the internal interface provided to libc. It will use 49 * pthread_once() from the threading library in a multi-threaded 50 * process and _libc_once() for a single-threaded library. Because 51 * _libc_once() uses the same ABI for the values in the pthread_once_t 52 * structure as the threading library, it is safe for a process to 53 * switch from _libc_once() to pthread_once() when threading is 54 * enabled. 55 */ 56 int 57 _once(pthread_once_t *once_control, void (*init_routine)(void)) 58 { 59 60 if (__isthreaded) 61 return (_pthread_once(once_control, init_routine)); 62 return (_libc_once(once_control, init_routine)); 63 } 64