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Implement a version of s_lock_try that doesn't cause the next s_lock

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call to panic when SL_DEBUG is set.  (SL_DEBUG is currently set
by default.)
This commit is contained in:
alc 1999-08-23 22:25:11 +00:00
parent a1492fd6d7
commit 0746aa3cb5
1 changed files with 20 additions and 20 deletions
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40
sys/i386/i386/simplelock.s
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@ -22,7 +22,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: simplelock.s,v 1.8 1998/01/19 17:33:08 tegge Exp $
* $Id: simplelock.s,v 1.9 1998/05/17 23:08:03 tegge Exp $
*/
/*
@ -143,6 +143,8 @@ bsl1: .asciz "rslock: cpu: %d, addr: 0x%08x, lock: 0x%08x"
* return (!test_and_set(&lkp->lock_data));
* }
*/
#ifndef SL_DEBUG
ENTRY(s_lock_try)
movl 4(%esp), %eax /* get the address of the lock */
movl $1, %ecx
@ -154,6 +156,23 @@ ENTRY(s_lock_try)
ret
#else /* SL_DEBUG */
ENTRY(s_lock_try)
movl 4(%esp), %edx /* get the address of the lock */
movl _cpu_lockid, %ecx /* add cpu id portion */
incl %ecx /* add lock portion */
xorl %eax, %eax
lock
cmpxchgl %ecx, (%edx)
setz %al /* 1 if previous value was 0 */
movzbl %al, %eax /* convert to an int */
ret
#endif /* SL_DEBUG */
/*
* void
@ -168,25 +187,6 @@ ENTRY(s_unlock)
ret
#ifdef needed
/*
* int test_and_set(struct simplelock *lkp);
*/
ENTRY(test_and_set)
movl 4(%esp), %eax /* get the address of the lock */
movl $1, %ecx
xchgl %ecx, (%eax)
testl %ecx, %ecx
setz %al /* 1 if previous value was 0 */
movzbl %al, %eax /* convert to an int */
ret
#endif /* needed */
/*
* These versions of simple_lock block interrupts,
* making it suitable for regions accessed by both top and bottom levels.