5e53a4f90f
Mainly focus on files that use BSD 2-Clause license, however the tool I was using mis-identified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts.
106 lines
3.3 KiB
C
106 lines
3.3 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2005, David Xu <davidxu@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "namespace.h"
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#include <pthread.h>
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#include "un-namespace.h"
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#include "thr_private.h"
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__weak_reference(_pthread_once, pthread_once);
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#define ONCE_NEVER_DONE PTHREAD_NEEDS_INIT
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#define ONCE_DONE PTHREAD_DONE_INIT
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#define ONCE_IN_PROGRESS 0x02
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#define ONCE_WAIT 0x03
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/*
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* POSIX:
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* The pthread_once() function is not a cancellation point. However,
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* if init_routine is a cancellation point and is canceled, the effect
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* on once_control shall be as if pthread_once() was never called.
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*/
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static void
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once_cancel_handler(void *arg)
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{
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pthread_once_t *once_control;
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once_control = arg;
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if (atomic_cmpset_rel_int(&once_control->state, ONCE_IN_PROGRESS,
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ONCE_NEVER_DONE))
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return;
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atomic_store_rel_int(&once_control->state, ONCE_NEVER_DONE);
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_thr_umtx_wake(&once_control->state, INT_MAX, 0);
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}
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int
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_pthread_once(pthread_once_t *once_control, void (*init_routine) (void))
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{
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struct pthread *curthread;
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int state;
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_thr_check_init();
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for (;;) {
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state = once_control->state;
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if (state == ONCE_DONE) {
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atomic_thread_fence_acq();
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return (0);
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}
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if (state == ONCE_NEVER_DONE) {
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if (atomic_cmpset_int(&once_control->state, state,
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ONCE_IN_PROGRESS))
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break;
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} else if (state == ONCE_IN_PROGRESS) {
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if (atomic_cmpset_int(&once_control->state, state,
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ONCE_WAIT))
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_thr_umtx_wait_uint(&once_control->state,
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ONCE_WAIT, NULL, 0);
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} else if (state == ONCE_WAIT) {
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_thr_umtx_wait_uint(&once_control->state, state,
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NULL, 0);
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} else
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return (EINVAL);
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}
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curthread = _get_curthread();
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THR_CLEANUP_PUSH(curthread, once_cancel_handler, once_control);
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init_routine();
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THR_CLEANUP_POP(curthread, 0);
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if (atomic_cmpset_rel_int(&once_control->state, ONCE_IN_PROGRESS,
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ONCE_DONE))
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return (0);
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atomic_store_rel_int(&once_control->state, ONCE_DONE);
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_thr_umtx_wake(&once_control->state, INT_MAX, 0);
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return (0);
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}
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