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- Add a mutex_wakeup() which clears the waiters flag and wakes all waiters. 

Will be needed to fix a problem with mutexes on sparc.
- mutex_tryenter(): fix a false "locking against myself" error.
This commit is contained in:
ad 2007-02-15 15:49:27 +00:00
parent 1fddd99f52
commit 10a11a26b3
2 changed files with 36 additions and 5 deletions
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38
sys/kern/kern_mutex.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: kern_mutex.c,v 1.3 2007/02/10 21:07:52 ad Exp $ */
/* $NetBSD: kern_mutex.c,v 1.4 2007/02/15 15:49:27 ad Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007 The NetBSD Foundation, Inc.
@ -49,7 +49,7 @@
#define __MUTEX_PRIVATE
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_mutex.c,v 1.3 2007/02/10 21:07:52 ad Exp $");
__KERNEL_RCSID(0, "$NetBSD: kern_mutex.c,v 1.4 2007/02/15 15:49:27 ad Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@ -206,6 +206,12 @@ MUTEX_RELEASE(kmutex_t *mtx)
MUTEX_GIVE();
mtx->mtx_owner = 0;
}
static inline void
MUTEX_CLEAR_WAITERS(kmutex_t *mtx)
{
/* nothing */
}
#endif /* __HAVE_SIMPLE_MUTEXES */
/*
@ -700,6 +706,29 @@ mutex_vector_exit(kmutex_t *mtx)
}
}
#ifndef __HAVE_SIMPLE_MUTEXES
/*
* mutex_wakeup:
*
* Support routine for mutex_exit() that wakes up all waiters.
* We assume that the mutex has been released, but it need not
* be.
*/
void
mutex_wakeup(kmutex_t *mtx)
{
turnstile_t *ts;
ts = turnstile_lookup(mtx);
if (ts == NULL) {
turnstile_exit(mtx);
return;
}
MUTEX_CLEAR_WAITERS(mtx);
turnstile_wakeup(ts, TS_WRITER_Q, TS_WAITERS(ts, TS_WRITER_Q), NULL);
}
#endif /* !__HAVE_SIMPLE_MUTEXES */
/*
* mutex_owned:
*
@ -742,8 +771,6 @@ mutex_tryenter(kmutex_t *mtx)
{
uintptr_t curthread;
MUTEX_WANTLOCK(mtx);
/*
* Handle spin mutexes.
*/
@ -751,11 +778,13 @@ mutex_tryenter(kmutex_t *mtx)
MUTEX_SPIN_SPLRAISE(mtx);
#ifdef FULL
if (__cpu_simple_lock_try(&mtx->mtx_lock)) {
MUTEX_WANTLOCK(mtx);
MUTEX_LOCKED(mtx);
return 1;
}
MUTEX_SPIN_SPLRESTORE(mtx);
#else
MUTEX_WANTLOCK(mtx);
MUTEX_LOCKED(mtx);
return 1;
#endif
@ -763,6 +792,7 @@ mutex_tryenter(kmutex_t *mtx)
curthread = (uintptr_t)curlwp;
MUTEX_ASSERT(mtx, curthread != 0);
if (MUTEX_ACQUIRE(mtx, curthread)) {
MUTEX_WANTLOCK(mtx);
MUTEX_LOCKED(mtx);
MUTEX_DASSERT(mtx,
MUTEX_OWNER(mtx->mtx_owner) == curthread);

3
sys/sys/mutex.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: mutex.h,v 1.2 2007/02/09 21:55:37 ad Exp $ */
/* $NetBSD: mutex.h,v 1.3 2007/02/15 15:49:27 ad Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007 The NetBSD Foundation, Inc.
@ -174,6 +174,7 @@ typedef struct kmutex kmutex_t;
void mutex_vector_enter(kmutex_t *);
void mutex_vector_exit(kmutex_t *);
void mutex_spin_retry(kmutex_t *);
void mutex_wakeup(kmutex_t *);
#endif /* __MUTEX_PRIVATE */