8a16b7a18f
Mainly focus on files that use BSD 3-Clause license. 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. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point.
127 lines
3.7 KiB
C
127 lines
3.7 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
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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, this list of conditions and the following 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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* 3. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* 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 <sys/types.h>
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#include <pthread.h>
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#include <libc_private.h>
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#include <spinlock.h>
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#include "thr_private.h"
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#define MAX_SPINLOCKS 72
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/*
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* These data structures are used to trace all spinlocks
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* in libc.
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*/
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struct spinlock_extra {
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spinlock_t *owner;
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struct umutex lock;
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};
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static struct umutex spinlock_static_lock = DEFAULT_UMUTEX;
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static struct spinlock_extra extra[MAX_SPINLOCKS];
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static int spinlock_count;
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static int initialized;
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static void init_spinlock(spinlock_t *lck);
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/*
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* These are for compatability only. Spinlocks of this type
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* are deprecated.
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*/
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void
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__thr_spinunlock(spinlock_t *lck)
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{
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struct spinlock_extra *_extra;
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_extra = lck->thr_extra;
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THR_UMUTEX_UNLOCK(_get_curthread(), &_extra->lock);
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}
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void
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__thr_spinlock(spinlock_t *lck)
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{
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struct spinlock_extra *_extra;
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if (!__isthreaded)
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PANIC("Spinlock called when not threaded.");
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if (!initialized)
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PANIC("Spinlocks not initialized.");
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if (lck->thr_extra == NULL)
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init_spinlock(lck);
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_extra = lck->thr_extra;
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THR_UMUTEX_LOCK(_get_curthread(), &_extra->lock);
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}
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static void
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init_spinlock(spinlock_t *lck)
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{
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struct pthread *curthread = _get_curthread();
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THR_UMUTEX_LOCK(curthread, &spinlock_static_lock);
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if ((lck->thr_extra == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
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lck->thr_extra = &extra[spinlock_count];
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_thr_umutex_init(&extra[spinlock_count].lock);
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extra[spinlock_count].owner = lck;
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spinlock_count++;
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}
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THR_UMUTEX_UNLOCK(curthread, &spinlock_static_lock);
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if (lck->thr_extra == NULL)
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PANIC("Warning: exceeded max spinlocks");
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}
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void
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_thr_spinlock_init(void)
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{
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int i;
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_thr_umutex_init(&spinlock_static_lock);
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if (initialized != 0) {
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/*
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* called after fork() to reset state of libc spin locks,
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* it is not quite right since libc may be in inconsistent
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* state, resetting the locks to allow current thread to be
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* able to hold them may not help things too much, but
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* anyway, we do our best.
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* it is better to do pthread_atfork in libc.
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*/
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for (i = 0; i < spinlock_count; i++)
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_thr_umutex_init(&extra[i].lock);
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} else {
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initialized = 1;
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}
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}
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