2 * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $FreeBSD: src/lib/libc_r/uthread/uthread_spinlock.c,v 1.8.2.2 2002/10/17 19:37:39 fjoe Exp $
35 extern unsigned int __sleep(unsigned int);
37 #include "namespace.h"
39 #include <sys/fcntl.h>
42 #include <sys/sched.h>
45 #include "un-namespace.h"
47 #include "libc_private.h"
48 #include "pthread_private.h"
51 _spinunlock(spinlock_t
*lck
)
57 * Lock a location for the running thread. Yield to allow other
58 * threads to run if this thread is blocked because the lock is
59 * not available. Note that this function does not sleep. It
60 * assumes that the lock will be available very soon.
63 _spinlock(spinlock_t
*lck
)
65 struct pthread
*curthread
= _get_curthread();
68 * Try to grab the lock and loop if another thread grabs
71 while(_atomic_lock(&lck
->access_lock
)) {
72 /* Block the thread until the lock. */
73 curthread
->data
.spinlock
= lck
;
74 _thread_kern_sched_state(PS_SPINBLOCK
, __FILE__
, __LINE__
);
77 /* The running thread now owns the lock: */
78 lck
->lock_owner
= (long) curthread
;
82 * Lock a location for the running thread. Yield to allow other
83 * threads to run if this thread is blocked because the lock is
84 * not available. Note that this function does not sleep. It
85 * assumes that the lock will be available very soon.
87 * This function checks if the running thread has already locked the
88 * location, warns if this occurs and creates a thread dump before
92 _spinlock_debug(spinlock_t
*lck
, char *fname
, int lineno
)
94 struct pthread
*curthread
= _get_curthread();
98 * Try to grab the lock and loop if another thread grabs
101 while(_atomic_lock(&lck
->access_lock
)) {
105 snprintf(str
, sizeof(str
), "%s - Warning: Thread %p attempted to lock %p from %s (%d) was left locked from %s (%d)\n", _getprogname(), curthread
, lck
, fname
, lineno
, lck
->fname
, lck
->lineno
);
106 __sys_extpwrite(2, str
, strlen(str
), O_FBLOCKING
, -1);
111 /* Block the thread until the lock. */
112 curthread
->data
.spinlock
= lck
;
113 _thread_kern_sched_state(PS_SPINBLOCK
, fname
, lineno
);
116 /* The running thread now owns the lock: */
117 lck
->lock_owner
= (long) curthread
;
119 lck
->lineno
= lineno
;