1 /*- 2 * Copyright (c) 2009 Hudson River Trading LLC 3 * Written by: John H. Baldwin <jhb@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "namespace.h" 32 #include <pthread.h> 33 #include "un-namespace.h" 34 #include "libc_private.h" 35 36 /* This implements pthread_once() for the single-threaded case. */ 37 static int 38 _libc_once(pthread_once_t *once_control, void (*init_routine)(void)) 39 { 40 41 if (once_control->state == PTHREAD_DONE_INIT) 42 return (0); 43 init_routine(); 44 once_control->state = PTHREAD_DONE_INIT; 45 return (0); 46 } 47 48 /* 49 * This is the internal interface provided to libc. It will use 50 * pthread_once() from the threading library in a multi-threaded 51 * process and _libc_once() for a single-threaded library. Because 52 * _libc_once() uses the same ABI for the values in the pthread_once_t 53 * structure as the threading library, it is safe for a process to 54 * switch from _libc_once() to pthread_once() when threading is 55 * enabled. 56 */ 57 int 58 _once(pthread_once_t *once_control, void (*init_routine)(void)) 59 { 60 61 if (__isthreaded) 62 return (_pthread_once(once_control, init_routine)); 63 return (_libc_once(once_control, init_routine)); 64 } 65