125 lines
3.7 KiB
C
125 lines
3.7 KiB
C
/*
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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 = (struct spinlock_extra *)lck->fname;
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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->fname == NULL)
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init_spinlock(lck);
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_extra = (struct spinlock_extra *)lck->fname;
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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->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
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lck->fname = (char *)&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->fname == 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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